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Spectral-Domain Optical Coherence Tomography Angiography of Choroidal Neovascularization
... Eliminating the need for dye injection, optical coherence computed tomography angiography is a non-invasive imaging method that may provide clear, high-resolution images of the retinal microvasculature. It functions by gathering and contrasting decorrelation data at a particular retinal area from successive OCT B-scans [8] . ...
... In the 4.5 x 4.5-mm whole ONH scan, the Type 2 diabetes group had Based on a clinical examination, Thompson et al. [14] assessed the vasculature of diabetic eyes that were reported to be free of diabetic retinopathy. On the OCTA picture, 8 [40%] of the 20 participants had non-clinically evident microaneurysms or capillary dropout. ...
... In contrast to slit-lamp biomicroscopy-based imaging method, optical coherence tomography angiography (OCTA) provides depth-resolved images though motion contrast and detecting blood ow signals, enabling visualization of the vasculature at speci c tissue depths [10,11]. Anterior segment-OCTA (AS-OCTA) has been used to assessing conjunctival microvascular changes in diabetes mellitus (DM) patients, however, few conjunctival OCTA studies of individuals with cardiovascular diseases are currently available [12]. ...
... Prolonged endothelial cell dysfunction and in ammatory responses can lead to decreased arterial wall elasticity and compliance, thereby causing alterations in vascular tortuosity and morphology [27]. In addition, OCTA constructs vascular images by detecting the motion of erythrocytes in the vessel [11]. However, the limitation of interscan time may result in the failure to capture blood ows with excessively fast or slow velocities [30]. ...
Background
To quantify conjunctival microvascular characteristics obtained by optical coherence tomographic angiography (OCTA) and investigate their relationship with the presence and severity of coronary artery disease (CAD).
Methods
This cross-sectional study included 103 consecutive CAD patients confirmed by coronary angiography and 125 non-CAD controls. The temporal conjunctivas along the limbus of each participant were scanned using OCTA. Quantification of conjunctival microvasculature was performed by AngioTool software. The severity of the disease was evaluated using SYNTAX and Gensini scores.
Results
Compared to the controls, the CAD group exhibited significantly lower vessel area density (30.22 ± 3.34 vs. 26.70 ± 4.43%, p < 0.001), lower vessel length density (6.39 ± 0.77 vs. 5.71 ± 0.89/m, p < 0.001), lower junction density (3.44 ± 0.56 vs. 3.05 ± 0.63/m, p < 0.001), and higher lacunarity (0.11 ± 0.03 vs. 0.14 ± 0.05, p < 0.001). Among all participants, lower vessel area density, lower vessel length density, lower junction density, and higher lacunarity were associated with greater odds of having CAD; the adjusted ORs (95% confidence intervals) per one SD decrease were 2.71 (1.71, 4.29), 2.51(1.61, 3.90), 2.06 (1.39, 3.05), and 0.36 (0.23, 0.58), respectively. Among CAD patients, junction density was negatively associated with the Gensini score (r=-0.359, p = 0.037) and the Syntax score (r=-0.350, p = 0.042) in women but not in men (p > 0.05).
Conclusions
Conjunctival microvascular characteristics were significantly associated with the presence of CAD. Junction density significantly associated with the severity of CAD among women patients.
... Nevertheless, at the best of our knowledge, no study focused on the MNV modifications after VEGF antagonist treatment in eyes affected by nAMD and mild NPDR. OCTA allows the clinician to capture depth-resolved information and definite images of MNV in nAMD 22,23 . For this reason, by means of OCTA, we analyzed the MNV size and flow area in both groups. ...
... To visualize the whole MNV, the methodology displayed by de Carlo et al. 22 was used. Briefly, manual segmentation was used to capture the choriocapillaris en face (CC-OCTA) image (slab 30 μm thick beginning 31 μm posterior to the RPE-Bruch's membrane complex). ...
The purpose of this study was to investigate the effect of diabetic retinopathy (DR) on longitudinal morphological changes in AMD-associated type 1 macular neovascularization using optical coherence tomography angiography (OCTA). We enrolled fifty treatment-naïve eyes with a diagnosis of exudative AMD and type 1 MNV. Twenty of 50 eyes were affected by mild DR. En face OCT angiography were examined for the MNV lesion area (mm²), the MNV flow area (mm²), the central macular thickness (CMT) and the BCVA. The OCTA acquisition was performed at the following visits: (i) before the loading phase (LP) of intravitreal injection of aflibercept (T1), and (ii) 1 month after the last intravitreal injection of loading phase comprising 3 monthly injections (T2). All morpho-functional parameters showed a significantly change at T2 compared to T1 values in both groups. Furthermore, we found a greater MNV area reduction after LP in eyes without DR (P = 0.023). With regard to the remaining parameters, no significant changes were found between two groups (P > 0.05). Our analysis revealed a less MNV area reduction after loading dose of anti-VEGF therapy in eyes affected by diabetic retinopathy.
... OCTA allows to visualise, characterise, monitor and quantify the vascular network of MNV membranes in co-registration with the structural OCT [13,14,16,22]. MNV detection on OCTA has been compared to FA by various authors, reporting sensitivity values between 50% and 100% for detection of MNV [17,[23][24][25][26][27]. These studies differed regarding the underlying disease, MNV subtypes, OCTA instruments, evaluated automatically provided slabs, approach of manual modification of slabs (if performed) as well as masking to other imaging modalities. ...
... Some studies used only the OCTA en face view without corresponding crosssectional OCTA [26]. Other studies did not report whether the cross-sectional view was taken into account in addition to OCTA en face images [17,25]. ...
Purpose
To evaluate sensitivity and specificity of swept source-optical coherence tomography angiography (SS-OCTA) en face images versus cross-sectional OCTA versus a combination of both for the detection of macular neovascularization (MNV).
Design
Prospective cohort study.
Participants
Consecutive patients with various chorioretinal diseases and subretinal hyperreflective material (SHRM) and/or pigment epithelial detachment (PED) on OCT possibly corresponding to MNV in at least one eye.
Methods
102 eyes of 63 patients with fluorescein angiography (FA), OCT and SS-OCTA performed on the same day were included. FA images, the outer retina to choriocapillaris (ORCC) OCTA en face slab, a manually modified en face slab (‘custom slab’), cross-sectional OCTA and a combination of OCTA en face and cross-section were evaluated for presence of MNV.
Main outcome measures
Sensitivity and specificity for MNV detection, as well as the concordance was calculated using FA as the reference.
Results
OCTA en face imaging alone yielded a sensitivity of 46.3% (automated)/78.1% (custom) and specificity of 93.4% (automated)/88.5% (custom) for MNV detection. Cross-sectional OCTA (combination with en face) resulted in a sensitivity of 85.4% (82.9%) and specificity of 82.0% (85.3%). Concordance to FA was moderate for automated en face OCTA ( κ = 0.43), and substantial for custom en face OCTA ( κ = 0.67), cross-sectional OCTA ( κ = 0.66) and the combination ( κ = 0.68).
Conclusion
Segmentation errors result in decreased sensitivity for MNV detection on automatically generated OCTA en face images. Cross-sectional OCTA allows detection of MNV without manual modification of segmentation lines and should be used for evaluation of MNV on OCTA.
... Since there is no masking effect in fluorescein angiography (FA), it can show the neovascular network more clearly and can provide qualitative and quantitative information about MNV [11,12]. In different studies, the sensitivity of OCTA to detect MNV was 50-100%, more than other imaging systems [13,14]. ...
Purpose
To evaluate the predictive factors of neovascular age-related macular degeneration (nAMD) with poor response to three loading doses of intravitreal bevacizumab (IVB).
Methods
A retrospective cohort study was performed on nAMD patients three loading IVB initial treatment. The patients were divided into two groups, without residual fluid on optical coherence tomography (OCT) images (Group 1) and with residual fluid (Group 2). Demographic data, OCT findings, and morphological features of macular neovascularization (MNV) in optical coherence tomography angiography (OCTA) were recorded.
Results
The study included one hundred thirty-six eyes of 120 patients (Group 1: n = 66 eyes, Group 2: n = 70 eyes). Central macular thickness, presence of intraretinal fluid, subretinal fluid, hyperreflective foci-band, pigment epithelial detachment (PED), and prechoroidal cleft were similar between the two groups. Pre-injection central choroidal thickness (CCT) was 214.17 ± 50.28 µm in Group 1 and 247.40 ± 60.55 µm in Group 2 (p = 0.021). PED width (p = 0.028) and PED area (p = 0.042) were statistically significantly higher in Group 1. When the morphology of MNV in OCTA was examined, branching (p = 0.736), loops (p = 0.442), peripheral arcade (p = 0.600), hypointense halo (p = 0.779), sea fan (p = 0.250), medusa (p = 0.255), pruned vascular tree pattern (p = 0.148), capillary fringe (p = 0.683) were similar in both groups. The presence of a closed circuit pattern was significantly higher in Group 2 (p = 0.028).
Conclusion
Initial CCT and closed circuit pattern MNV were higher in IVB-resistant cases. It was observed that PEDs with large bases and areas responded significantly better to loading therapy. The presence of a closed-circuit pattern was an independent risk factor for poor response to loading therapy.
Retrospectively registered. Registration number: 2011-KAEK-25 2023/05-08.
... El Ameen et al (23) identified two distinct type 2 morphologies: The Medusa and the glomerulus patterns, typically associated with a main branch. De Carlo et al (24) have used a fiber descriptor for MNV morphology. A study conducted by Kuehlewein et al (25) found that among highly organized CNV lesions observed through OCTA, 55% exhibit the Medusa type, 21% the seafan type and 24% an indistinct type. ...
The present study aimed to examine the optical coherence tomography angiography (OCTA) parameters associated with macular neovascularization (MNV) in patients diagnosed with neovascular age-related macular degeneration (nAMD) and treated with either intravitreal conbercept (IVC) or ranibizumab (IVR). It enrolled 39 nAMD patients presenting with MNV, including 23 in the IVC group and 16 in the IVR group. All participants were treatment-naïve with intravitreal therapy and they underwent treatment following a ‘3+PRN’ regimen. The MNV patterns identified through OCTA were categorized as Medusa, tangled, seafan and other variations. Key outcome measures encompassed best-corrected visual acuity (BCVA), MNV vascular area (MNV-VA), MNV vascular density (MNV-VD) ratio and central macular thickness (CMT). In the present study, 44 eyes were included, with 28 eyes undergoing treatment with IVC and 18 eyes with IVR. On day 90, there was a statistically significant improvement in mean BCVA from baseline among all patients treated with IVC (P=0.002). Notably, improved outcomes were observed in those with the ‘tangled’ pattern compared with the other three patterns (P=0.007). CMT exhibited a significant decrease from baseline (P=0.007), with consistent improvement observed across all four patterns (P=0.052) on day 90. The mean MNV-VA decreased in all patients, reaching statistical significance for the Medusa pattern (P=0.008), although the improvement in visual acuity was deemed unsatisfactory. Patients with the seafan pattern treated with IVR improved significantly in BCVA (P=0.042). The mean CMT significantly improved from baseline (P=0.001), consistent across the four patterns (P=0.114). Significant improvements were noted in the mean MNV-VA for the seafan pattern and in the mean MNV-VD ratio for the other patterns. The two regimens had no significant differences regarding BCVA, CMT, and MNV parameters. Conbercept emerged as a viable treatment option for patients presenting with tangled MNV patterns. On the other hand, ranibizumab might be considered an effective intervention for individuals with seafan MNV patterns. Notably, the Medusa MNV pattern was associated with a morphologic configuration indicative of a poor prognosis.
... Optical coherence tomography angiography (OCTA), allowing visualization of the retinal and choroidal vasculature noninvasively, has been reported to be useful in treating AMD patients in clinical situations. By providing visualization of macular neovascularization (MNV), OCTA facilitates the assessment of AMD patients, particularly through observation of MNV features and their responses to treatment [4,5]. Specifically, OCTA proves to be a useful imaging modality in AMD treated with a PRN regimen of anti-VEGF by monitoring the dynamic vascular changes [6]. ...
Background
To identify the macular neovascularization (MNV) features in exudative age-related macular degeneration (AMD) patients who exhibited residual fluid after receiving three loading doses of aflibercept.
Methods
Patients were classified into two groups: Group 1, which did not exhibit intraretinal fluid (IRF) and subretinal fluid (SRF), and Group 2, which did exhibit IRF and/or SRF. Optical coherence tomography angiography (OCTA) features were assessed and compared between the groups.
Results
A total of 101 eyes were enrolled; 65 for Group 1 and 36 for Group 2. No significant differences were found in baseline MNV size (2.94 ± 2.51 µm² vs. 2.22 ± 2.26 µm², P = 0.178) or vessel density (47.1 ± 15.4 % vs. 41.3 ± 10.5%, P = 0.052) between Groups 1 and 2. There were significant differences in the presence of loops (52.3% vs. 75%, P = 0.026) and peripheral arcades (29.2% vs. 55.6%, P < 0.001) at baseline between the two groups. In Group 1, there was a significant reduction in the presence of branching (P < 0.001) and loops (P = 0.016) after treatment. In Group 2, only the presence of branching decreased significantly (P < 0.001) after treatment. Multivariable analysis revealed that the presence of a peripheral arcade (B = 4.77, P = 0.001) was significantly associated with residual fluid.
Conclusions
Although responding to treatment, the presence of loops and peripheral arcades in exudative AMD patients may contribute to residual fluid following the three loading doses of aflibercept. The peripheral arcade, in particular, may play a more significant role in the presence of residual fluid.
... Clinically, in vivo imaging includes conventional techniques using both fluorescein (FA) and indocyanine green angiography (ICGA) (Gelisken et al., 1998;Yannuzzi, 2011). In addition, optical coherence tomography angiography (OCTA) (de Carlo et al., 2015a(de Carlo et al., , 2015bWong et al., 2011) and spectral domain optical coherence tomography (SD-OCT) are now routinely used in the clinic (Margolis and Spaide, 2009;Mrejen and Spaide, 2013;Ferrara et al., 2016;Koh et al., 2017;Wang et al., 2018). Although, the general distribution and pattern of the choroidal vasculature of primates and other species including rodents has been described, a reliable method for the qualitative and quantitative histological assessment of choroidal vasculature in pigmented mice would benefit from the removal of melanin pigment. ...
... Optical coherence tomography (OCT) allows detailed visualization and characterization of macular anatomy, and classification of AMD according to the risk of exudative progression 4 . The advent of OCT angiography (OCT-A) has allowed rapid non-invasive diagnosis of MNV and has also led to the realization that many patients with a diagnosis of intermediate AMD may indeed have nonexudative MNV 15,16 . Type 1 MNV is a neovascular complex between the RPE and Bruch's membrane, while type 2 MNV lesions traverse the RPE into the subretinal space. ...
Purpose
To systematically review and report the rate of exudative progression over time in patients with non-exudative macular neovascularization (MNV) in age-related macular degeneration (AMD).
Design
Systematic review with prevalence meta-analyses and individual participant meta-analysis.
Methods
We searched 10 literature databases on March 26, 2023, for studies of consecutive patients with treatment-naïve non-exudative MNV in AMD. The primary outcome of interest was time from diagnosis to exudative progression. We conducted meta-analyses on the prevalence of exudative progression at 1 and 2 years. Where possible, we extracted individual participant data from studies and conducted an individual participant meta-analysis and explored the exudative progression using a time-to-event curve.
Results
We identified 16 eligible studies with a total of 384 eyes with non-exudative MNV. Exudative progression had occurred in 20.9 % (95 % CI: 13.1–29.8) of eyes at 1 year and in 30.7% (95%CI: 21.8–40.4%) at 2 years. Similar results were observed in the individual participant meta-analysis, showing exudative progression in 18.9% (95%CI: 13.5–26.3%) of eyes at 1 year and 31.3% (95%CI: 24.2–40.0%) at 2 years. Risk factors for a fast exudative progression were the presence of subretinal lipid globules, large MNV areas, rapid MNV growth, growth in pigment epithelium detachment height and width, appearance of a branching pattern, and development of a hyporeflective halo around the MNV.
Conclusions
Non-exudative MNVs in AMD are at high risk of exudative progression. Recognition of these lesions may allow for better individualized follow-up regimens in which closer monitoring may facilitate earlier diagnosis of exudative progression.
... Optical coherence tomography (OCT) provides a crosssection retinal imaging and has been clinically adopted to observe structural changes of retina [6] . Optical coherence tomography angiography (OCTA) is a non-invasive technique for detection of retinal and choroidal vascular changes, providing 3D mapping of both choroidal and retinal microvasculature [7] . It can image not only the superficial capillary plexus but also the deep capillary plexus and allows detection of retinal vessel density through motion contrast imaging and high-speed scanning [8] . ...
... This is in contrast to traditional fluorescein angiogram (FA) images ( Figure 1D), which capture blood flow and vessels as an en face image aggregated from the entire thickness of the retina without the ability to study blood flow within individual retinal layers [4,5]. Novel approaches to OCTA image analysis have increasingly adopted volume rendering to visualize the full 3D vasculature instead of the Clinically, OCTA enables the characterization of a wide variety of vascular pathological features, including micro-and macro-aneurysms [11][12][13], capillary remodeling [6], neovascularization [14][15][16], macular telangiectasia [10,17], retinal non-perfusion [18], and venous malformations [15,19]. Consequently, OCTA has opened up a new paradigm in the diagnostic imaging of retinal vascular diseases that will deepen our understanding of these conditions and may ultimately result in clinical benefit for patients. ...
Traditionally, abnormalities of the retinal vasculature and perfusion in retinal vascular disorders, such as diabetic retinopathy and retinal vascular occlusions, have been visualized with dye-based fluorescein angiography (FA). Optical coherence tomography angiography (OCTA) is a newer, alternative modality for imaging the retinal vasculature, which has some advantages over FA, such as its dye-free, non-invasive nature, and depth resolution. The depth resolution of OCTA allows for characterization of the retinal microvasculature in distinct anatomic layers, and commercial OCTA platforms also provide automated quantitative vascular and perfusion metrics. Quantitative and qualitative OCTA analysis in various retinal vascular disorders has facilitated the detection of pre-clinical vascular changes, greater understanding of known clinical signs, and the development of imaging biomarkers to prognosticate and guide treatment. With further technological improvements, such as a greater field of view and better image quality processing algorithms, it is likely that OCTA will play an integral role in the study and management of retinal vascular disorders. Artificial intelligence methods—in particular, deep learning—show promise in refining the insights to be gained from the use of OCTA in retinal vascular disorders. This review aims to summarize the current literature on this imaging modality in relation to common retinal vascular disorders.
... Патогенетически обоснованным методом лечения ХНВ I типа при хронической ЦСХРП являются интравитреальные введения ингибиторов ангиогенеза (ИВВИА) [14][15][16][17][18]. При этом эффективность лечения ингибиторами ангиогенеза в виде монотерапии значительно ниже, чем при лечении ХНВ I типа при нВМД. ...
Purpose : to evaluate the effectiveness of combined treatment of chronic central serous chorioretinopathy (CSCRP) complicated by type 1 choroidal neovascularization (CNV) by subthreshold micropulse laser exposure (SMILE) and intravitreal injection of angiogenesis inhibitors ( IIAI). Material and methods . 37 patients (20 men and 17 women) with monolateral chronic recurrent CSCRP complicated by type 1 CNV, aged 35 to 57 (ave. 43.6 ± 6.7 yrs.) at the moment of first referral, were divided into two groups. The retrospective group included 15 patients (15 eyes) whose first phase of treatment consisted in IIAI (up to 5 injections with an interval of one month). Those who showed no treatment effect were given a SMILE procedure one day before the 6th injection. If neurosensory retinal detachment persisted, the combined treatment (SMILE + IIAI) was repeated monthly until the neurosensory retina could be fully attached, whereupon the patients were transferred to monotherapy with anti-VEGF injections, gradually increasing the interval between the injections. The main group included 22 patients (22 eyes), whose treatment began with a single IIAI. If no neurosensory retinal detachment resorption occurred, the patients received a SMILE procedure one day before the second IIAI injection. The combined treatment was repeated monthly until neurosensory retinal detachment completely resorbed, then the treatment continued with IIAI alone with a gradual increase of intervals between the injections. Results. The number of IIAI in the main group (5 to 8, ave. 6.1 ± 0.8) was significantly lower than in the retrospective group (8 to 10, ave. 8.8 ± 0.77). Best corrected visual acuity increased in both groups, but the main group showed a better central photosensitivity, which is associated with the faster reattachment of neurosensory retina. By the end of the follow-up period, the area of type 1 CNV, and the thickness of the choroid were significantly lower in the main group as compared to the retrospective group. The combined treatment did not cause a single case of complication. Conclusion. The proposed combination of laser exposure followed by IIAI is a safe method for treating complicated forms of CSCRP, which quickens the resorption of subretinal fluid and reduces the number of treatment procedures.
... (9) OCT angiography permits the imaging of retinal and choroidal circulation via motion contrast imaging. (10) In-contrast to OCT, OCT angiography can image vascular changes of diabetic maculopathy such as neovascularization and non-perfused areas (ischemic maculopathy). (11) ...
... Currently, dye angiography remains the gold standard for diagnosing type 1 CNV in AMD [24]. However, in regard to CNV in the pachychoroid spectrum, this identification is more difficult. ...
Background: To investigate the sensitivity and specificity of optical coherence tomography angiography (OCTA) versus dye angiography for detecting pachychoroid neovasculopathy (PNV) and to determine the morphological factors that affect PNV detection. Methods: Patients with pachychoroid phenotype were prospectively enrolled and underwent multimodal imaging examinations during the same visit. The diagnostic accuracy of fundus fluorescein angiography (FFA), FFA combined with indocyanine green angiography (ICGA) and OCTA for PNV was evaluated using multimodal imaging as the reference. Multimodal parameters of PNV were qualitatively and quantitatively assessed. Results: PNV was detected in 58 eyes (46 patients) out of 340 pachychoroid eyes (201 patients) according to reference standard. Patients with PNV eyes were significantly older (54.6±7.56 vs. 48.2±9.1 years), were more likely to have a chronic central serous chorioretinopathy history (CSC) (93.1% vs. 12.4%) and had a worse visual acuity (0.30±0.22 vs. 0.58±0.30) than those without PNV eyes (all P<0.001). The sensitivity of FFA, FFA combined with ICGA, and OCTA in detecting PNV in patients with the pachychoroid phenotype was 67.2%, 63.8% and 98.3%, respectively, and the specificity was 87.2%, 96.8% and 100.0%, respectively. PNV not identified by dye angiography was more manifested as the absence of late plaque hypercyanescence on ICGA (P<0.001) and overall smaller capillaries without a distinct pattern (P=0.001), fewer core vessels (P=0.002) and smaller area (P=0.044). Conclusions: OCTA showed superior detection rate and accuracy for identifying PNV over dye angiography. In case multimodal imaging is unavailable, OCTA can be an effective and noninvasive method for monitoring PNV and guiding treatment decisions.
... Patients with MS have been reported to be more likely to develop ischemic heart disease, stroke, and peripheral vascular disease (Marrie et al., 2015). Optical coherence tomography angiography (OCTA) is a novel imaging technique visualizing the retinal and choroidal microvasculature noninvasively (de Carlo et al., 2015). Without contrast agents or dye injection, OCTA images the microvasculature though detecting the motion contrast of blood cells (Kashani et al., 2017). ...
Purpose
A systematic review and meta-analysis was conducted to investigate changes in retinal and choroidal microvasculature in patients with multiple sclerosis (MS) using optical coherence tomography angiography (OCTA).
Methods
PubMed and Google Scholar were searched for studies that compared retinal and choroidal microvasculature between MS and healthy controls (HC) with OCTA. MS patients were divided into 2 groups: MS with (MSON) or without optic neuritis (MSNON).
Results
Totally, 13 studies including 996 MS eyes and 847 HC eyes were included. Compared with the HC, the vessel density of the whole superficial vascular complex (SVC) was reduced by 2.27% and 4.30% in the MSNON and MSON groups, respectively. The peripapillary vessel density was 2.28% lower and 4.96% lower in the MSNON and MSON groups, respectively, than in the HC. Furthermore, the MSON group had significant lower vessel density of the SVC (mean difference [MD] = −2.17%, P < 0.01) and lower peripapillary vessel density (MD = −2.02%, P = 0.02) than the MSNON group. No significant difference was found in the deep vascular complex or choriocapillaris densities among MSNON, MSON or HC groups (P > 0.05). Meta-regression analyses suggested that illness duration and the Expanded Disability Status Scale scores of MS patients were possible sources of heterogeneity (P < 0.05).
Conclusion
The retinal SVC and peripapillary vessel density decreased significantly in MS eyes, especially in eyes with optic neuritis. Retinal microvasculature is a potential biomarker of disease progression in MS.
... 250 mm for cRORA.23 SD-OCT qCNV Presence of "double layer sign" or a "shallow irregular RPE elevation" (SIRE) without any signs of exudative activity.24 Presence of neovascular network, indicated by a sub-RPE flow signal in OCTA at the corresponding retinal location.25 SD-OCT, OCT-A BM ¼ Bruch's membrane; CFP ¼ color fundus photography; FAF ¼ fundus autofluorescence; HRF ¼ hyperreflective foci; i/cRORA ¼ incomplete/complete retinal pigment epithelium and outer retinal atrophy; OCTA ¼ OCT angiography; PA ¼ pigmentary abnormalities; PED ¼ pigment epithelium detachment; qCNV ¼ quiescent choroidal neovascularization; RPD ¼ reticular pseudodrusen; RPE ¼ retinal pigment epithelium; SD ¼ spectral-domain. ...
Purpose:
To report the prevalence and topographic distribution of structural characteristics in study participants with age-related macular degeneration (AMD) and controls in the cross-sectional study part of the MACUSTAR study (ClinicalTrials.gov Identifier: NCT03349801).
Design:
European, multicenter cohort study.
Subjects:
301 eyes of 301 subjects with early (n=34), intermediate (n=168) and late AMD (n=43), as well as eyes without any AMD features (n=56).
Methods:
In study eyes with intermediate AMD (iAMD), the presence of structural AMD biomarkers including pigmentary abnormalities (PA), pigment-epithelium detachment (PED), refractile deposits, reticular pseudodrusen (RPD), hyperreflective foci (HRF), incomplete/complete retinal pigment epithelium and outer retinal atrophy (i/cRORA)) and quiescent choroidal neovascularization (qCNV) was systematically determined in the prospectively acquired multimodal retinal imaging cross-sectional data set of MACUSTAR. Retinal layer thicknesses and the retinal pigment-epithelium drusen complex (RPEDC) volume were determined for the total study cohort in spectral-domain optical coherence tomography (SD-OCT) imaging using a deep-learning based algorithm.
Main outcome measures:
Prevalence and topographic distribution of structural iAMD features.
Results:
A total of 301 study eyes of 301 subjects with a mean (± standard deviation) age of 71.2 ± 7.20 years (63.1% female) were included. Besides large drusen, the most prevalent structural feature in intermediate AMD (iAMD) study eyes were PA (57.1%), followed by HRF (51.8%) and RPD (22.0%). PED lesions were observed in 4.8%, vitelliform lesions in 4.2%, refractile deposits in 3.0% and qCNV in 2.4%. Direct precursor lesions for manifest retinal atrophy were detected in 10.7% (iRORA) and 4.2% (cRORA) in iAMD eyes. Overall, highest RPEDC volume with a median of 98.92 x 10-4 mm³ was found in iAMD study eyes. Spatial analysis demonstrated a predominant distribution of RPD in the superior and temporal subfields at a foveal eccentricity of 1.5-2 mm, while HRF and large drusen had a distinct topographic distribution involving the foveal center.
Conclusions:
Detailed knowledge of the prevalence and distribution of structural iAMD biomarkers is vital to identifying reliable outcome measure for disease progression. Longitudinal analyses are needed to evaluate their prognostic value for conversion to advanced disease stages.
... With regard to the sensitivity of each device depending on MNV type, type 1 MNV visualization achieved a sensitivity of 100% (p = 0.444) using the SS-OCTA device (PlexElite), 78.6% using the Heidelberg OCT2 (p = 0.09) and 61.6% using the AngioVue (p = 0.03). Notably, in our study, the detection of type 1 MNVs using the AngioVue was slightly lower than the current literature [6,[20][21][22], with the overall detection rates varying from 32% to 90% [13,23]. ...
Background and Objectives: The aim of this study was to report the characteristics of macular neovascularization (MNV) with undetectable flow on optical coherence tomography angiography (OCTA) in neovascular age related macular degeneration (nAMD), and compare them with the characteristics of detectable MNV. Materials and Methods: Patients with a diagnosis of nAMD who underwent dye imaging and OCTA in the same day were included and divided into two groups: undetectable and detectable flow on OCTA. Three OCTA devices were used, two with spectral-domain technology (AngioVue, RTVue 100xAvanti, Optovue, Freemont, CA, USA and Heidelberg OCT2 Beta Angiography Module, Heidelberg Engineering, Germany) and one swept-source OCTA (PlexElite 9000; Carl Zeiss Meditec, Inc., Dublin, CA, USA). We studied the demographics, neovascularization characteristics, and OCTA device and acquisition characteristics for both groups. Results: A global comparison between Group 1 and Group 2 was made, followed by an analysis of variables associated with (un)detectability for each OCTA device. A total of 108 eyes were included: 90 in the detectable group (Group 1) and 18 in the undetectable group (Group 2), corresponding to a global sensitivity of OCTA for the detection of MNV of 83.49%. There was a statistically significant difference between the two groups regarding MNV type (p = 0.02) and PED height (p = 0.017). For the three devices, detection sensitivity with automatic segmentation was significantly lower than with manual segmentation. For Heidelberg, PED Height and scan quality explained 68.3% of the undetectability. For AngioVue, PED Height and absence of hemorrhage explained 67.9% of undetectability. Conclusions: In this study, we found a global sensitivity of 83.49% for the three OCTA devices combined, with a range from 55.5% to 96.26% depending on the segmentation and OCTA device. This means that undetectable/undetected MNV can represent up to 45% of the examinations, eventually misdiagnosing choroidal neovascularization for 1 out every 2 patients.
... A later study found the sensitivity and specificity of OCT-A in detection of CNV associated with nAMD to be 50% and 91%, respectively. (11) The sample size was, however, small and the classification criteria for CNV activity were not clearly defined; it is likely that the lack of discrimination between active and inactive disease resulted in the highly The sensitivity of OCT-A in detection of angiographically-proven CNV lesions associated with nAMD was reported in another study. (12) Masked observers were asked to assess OCT-A scans of eyes with dry AMD, nAMD, and healthy subjects. ...
... Some studies have found an increased prevalence of MNV after treatment with laser 8 9 or photodynamic therapy (PDT) 9 10 in CSC, which may be caused by rupture of the BM after laser therapy or choroidal ischaemia and excessive vascular endothelial growth factor (VEGF) production after PDT. 9 The emergence of optical coherence tomography angiography (OCTA), an innovative imaging technique that does not require a fluorescent dye, facilitates the visualisation of three-dimensional images of the retina and choroidal microcirculation. 3 By comparing static tissue and locomotive blood cells, a split-spectrum amplitudedecorrelation angiography algorithm is implemented to improve the detection ability of blood flow signals and abnormal neovascularisation. 3 11 Furthermore, the specificity and sensitivity of OCTA for detecting MNV are comparable with values obtained using invasive fluorescein angiography (FA). ...
Objective
To identify the risk factors and characteristics of central serous chorioretinopathy (CSC) with subsequent macular neovascularisation (MNV) detected on optical coherence tomography angiography (OCTA).
Methods and analysis
We included patients from six institutions who were initially diagnosed with CSC and subsequently did or did not develop MNV detected by OCTA. Potential influencing factors were identified by evaluating the patients’ baseline demographics, multimodal fundus imaging, treatment options, recurrence and outcomes in both groups.
Results
We enrolled 176 eyes in 152 patients (112 men, 40 women; mean age: 52.1±10.4 years) with a mean follow-up of 30.4±16.3 months. Secondary MNV was present in 23 eyes (13.1%), and non-MNV was observed in 153 eyes (86.9%) by OCTA. Multivariate analysis revealed that older age (OR 1.06; 95% CI 1.01 to 1.11; p=0.014), chronic CSC (OR 3.05; 95% CI 1.12 to 8.30; p=0.029), leakage sites within the fovea on fluorescein angiography (OR 7.60; 95% CI, 1.89 to 30.48; p=0.004) and recurrent fluid within the first year (OR 5.12; 95% CI 1.66 to 15.77; p=0.012) were risk factors for subsequent MNV. Moreover, eyes with CSC complicated with MNV were characterised by poor visual acuity and low complete fluid resolution rates.
Conclusion
The factors associated with MNV secondary to CSC were older age, higher rates of chronic CSC and recurrence, and foveal leakage points on fluorescein angiography.
... [10][11][12] Thus, OCTA has the advantage of using an intrinsic contrast agent (i.e., RBCs) to differentiate blood vessels from surrounding tissues. With three dimensional (3D) and high-spatial resolution imaging ability of small vessels, OCTA has been widely used in a variety of studies, such as angiography of retina vessels in ophthalmology, [13][14][15][16][17][18][19] cerebrovascular perfusions in neuroscience, 20,21 cancer biology, 22,23 and skin diseases. [24][25][26][27] Despite the fast adoption in a variety of applications, OCTA is still facing several challenges, such as realizing quantitative detection of the blood flow 28 and the tail artifacts beneath big vessels. ...
Significance
A long-standing challenge of the blood vessel tail artifacts along the axial direction prevents optical coherence tomography angiography (OCTA) for a comprehensive three-dimensional (3D) vascular mapping. Addressing the blood vessel tail artifacts issue will make OCTA to be a real 3D blood vessel structural imaging technique, which in combination with OCT-based blood flow velocity measurements will pave the way for a simpler and robust 3D imaging of the capillary transit time, one important parameter for the evaluation of micro circulation.
Approach
We first described the basic principles of OCTA imaging, discussed the origin of blood vessel tail artifacts in an OCTA image, then reviewed the existing OCTA techniques for tail artifacts suppression, and at last we envisioned the potential solutions for effective OCTA tail artifacts suppression.
Results
The origin of blood vessel tail artifacts is due to the multiple scattering of photons with flowing red blood cells, which elongates the light path of the dynamic signal from vessel lumen to the tail regions. High numerical aperture implementation, subtraction-based post-data processing, Hessian filtering, and high acquisition rate-based dynamic analysis methods have been proposed to address the blood vessel tail artifacts issue in OCTA.
Conclusions
High acquisition rate-based dynamic analysis in combination with Hessian filtering have the potential to effectively suppress the blood vessel tail artifacts and in the meantime preserve flows in small vessels within the tail region, providing real 3D OCTA imaging of blood vessel structures.
... The DR and DME diagnoses are performed by looking for the presence of microaneurysms, intraretinal hemorrhages, exudates and edema [7][8][9] . The evaluation of the thickness of the neurosensory retina, retinal pigment epithelium, and choroid are analyzed independently for the AMD diagnosis [10,11] . ...
... Optical Coherence Tomography Angiography (OCTA) is a new technology that allows rapid examination and offers high-quality images of the retinal vasculature [4,5]. Using contrast imaging, this technology allows a quantitative assessment of the retinal and choroidal microvasculature which includes the optic nerve head (ONH), the peripapillary region, and the macular region [6,7], being, therefore, a non-invasive technique safer than conventional angiography (it does not require any injection of a contrast agent) [8]. ...
To evaluate the differences in peripapillary and macular vascular parameters by optical coherence tomography angiography (OCTA) between patients with primary congenital glaucoma (PCG) and healthy controls; and to determine their diagnostic accuracy.
Observational, cross-sectional study including 39 eyes with PCG and 78 healthy eyes. Only one eye per patient was included. All included patients underwent a comprehensive ophthalmic examination and peripapillary and macular analysis were performed by AngioplexTM OCTA (Cirrus HD-OCT 5000) with a 4.5 × 4.5 mm optic nerve head scan and 6 × 6 mm macular scan. Global data and quadrant data from peripapillary vascular parameters and global data and circular sectors data from macular superficial plexus parameters were compared between groups. The glaucoma discrimination capability of these parameters was calculated as areas under the receiver operating characteristics curve (AUC ROC).
Mean age was 14.1 ± 8.7 years for the PCG patients and 11.7 ± 6.2 years for controls (p = 0.093). All vascular peripapillary measurements (global and quadrants; all p < 0.001) and all macular measurements (p < 0.042) excepting perfusion density in the inner circle (p = 0.087), were reduced in the PCG group compared to controls. According to AUC ROC, peripapillary (all ≥ 0.706) and macular parameters (all ≥ 0.699) showed good diagnostic capacity. AUC ROC for the most discriminatory measurements corresponding to blood flux index (0.887) and whole macula vascular density (0.855) were similar (p = 0.085).
Peripapillary and macular vascular parameters by OCTA are decreased in patients with PCG, showing a good capacity to discriminate between normal and glaucomatous eyes.
... ОКТ-ангиография (OКTA) представляет собой неинвазивный метод первой линии диагностики влажной ВМД, показавший высокую чувствительность и специфичность в выявлении ХНВ. В настоящее время показана целесообразность применения OКTA при ГА с целью диагностики ХНВ и оценки состояния кровотока на уровне хориокапилляров [19,20]. ...
The atrophic form of late age-related macular degeneration (AMD) is a common cause of severe vision loss. Recently, a new classification system has been proposed, which identifies two types of atrophy in the late stage of AMD that require a more detailed study: (1) drusenassociated geographic atrophy (GA), which is the final stage of progression of dry AMD, and (2) macular atrophy (MA), which occurs in wet AMD, including the period of AMD treatment with angiogenesis inhibitors. Purpose: an integrated analysis of clinical and morphometric signs of atrophic AMD forms. Material and methods. 48 people (61eyes) aged 48–84 with GA (group 1) and MA (group 2) and a control group, recruited from age-matching 25 healthy volunteers (35 eyes), underwent standard ophthalmological examinations, fundus autofluorescence (FAF) with lesion area measurement, fundus photography, optical coherence tomography (OCT) in the standard mode and Enhanced Depth Imagine Mode, Multicolor, and OCT angiography. Results. The comparative analysis of two atrophic AMD forms showed that in GA eyes, foci of atrophy capturing the fovea were significantly more common, while, contrariwise in MA eyes atrophic foci not capturing the fovea were more frequent (p < 0.05). Photoreceptor tubulation was diagnosed mainly in eyes with GA (p < 0.05). The morphometric analysis showed a significant decrease in the subfoveal thickness of the choroid in the groups with GA and MA as compared to the control (p < 0.05), whilst no significant differences between two groups were noted. The assessment of the frequency of occurrence of types of fundus AF patterns in groups 1 and 2 followed by a comparative analysis, showed the presence of all types of patterns in GA patients, including the heterogeneous and the bordering pattern (p < 0.05). In the MA group, diffuse and focal types of patterns were revealed, while the frequency of the diffuse pattern turned out to be significantly more frequent (p < 0.05). Conclusion. The integrated analysis revealed the main semiological signs and morphometric parameters, their features and prevalence in GA and MA, which may have diagnostic and prognostic importance for the management and treatment of patients with AMD.
... Recent publications have shown that OCTA specifically indicates non-perfusion in DR [11] , presenting an objective, automatic analysis of macular capillary NP as a possible indication of central ischemia [12] . The disturbance of photoreceptors [13] , the disruption of the external limiting membrane [ELM] and the disorganisation of the retinal inner layers [DRIL] in OCT in diabetic patients could seem to be credible indicators of underlying non-perfusion [14] . ...
Background: Diabetic retinopathy is a common deficiency of diabetes mellitus. Diabetic macular ischemia [DMI] is a permanent form of diabetic maculopathy, and its presence reduces the potential benefits of diabetic retinopathy management. Optical coherence tomography [OCT] is used to precisely and reliably measure the macular thickness and outline the retinal layers. Optical coherence tomography angiography [OCTA] can be utilized as a reliable tool to classify the superficial capillary plexus [SCP], the deep capillary plexus [DCP] and the capillary non-perfusion [NP]. Aim of the work: The current research aimed to investigate the correlation between macular non-perfusion that diagnosed by OCTA and patterns of macular layers that diagnosed by OCT scans through the same parts, in a trial to help in the evaluation of both structural and vascular integrity. Patients and Methods: The study included 250 eyes of 125 diabetic patients. All study participants were scanned by OCTA. OCT angiograms were re-sampled with OCT scans from the same region, permitting synchronous evaluation of structure and blood flow. Results: 250 of 125 diabetic patients were categorized into two groups according to capillary NP, ischemic [G1] and non-ischemic [G2]. In current study the incidence of DMI was 40%. The incidence of DCPNP was 100% in eyes with DMI while the incidence of SCPNP was 71%. The incidence of foveal avascular zone [FAZ] irregularity, disorganization of the retinal inner layers [DRIL], inner/outer segment IS/OS and external limiting membrane ELM disruptions were 100%, 83%, 95%, 71% respectively among eyes with DMI. DCPNP was more found in all eyes with FAZ irregularity, DRIL, IS/OS and ELM disruption than SCP NP which makes it as the central cause of structural changes in the retina during ischemia. There was a strong positive correlation between the appearance of FAZ irregularity, DRIL, IS/OS and ELM disruption with each of the duration and severity of DR. Conclusion: FAZ irregularity, DRIL, IS/OS and ELM disruption are considered reliable OCT/OCTA findings that reflect an underling DMI and their existence can influence the visual prognosis.
The study aimed to assess different choroidal neovascular network characteristics in relation to changes in best corrected visual acuity (BCVA) over 3 and 12 months following treatment. Using optical coherence tomography angiography, the choroidal neovascular complexes of 46 treatment naïve patients with neovascular age-related macular degeneration (nAMD) were evaluated. The change in BCVA from baseline to 3 months and 12 months after treatment was recorded. The mean vessels percentage area, junctions density, lacunarity, and fractal dimension were significantly correlated with the change of BCVA from baseline to month 3 (P = 0.003, 0.046, 0.007, and 0.005 respectively). FD and vessels percentage area were correlated with the change of BCVA from baseline to month 12 (P = 0.023 and 0.023 respectively). The findings suggest that baseline characteristics of choroidal neovascular complexes may serve as predictors for BCVA changes following treatment with aflibercept in nAMD patients.
Purpose
To investigate the impact of diabetic retinopathy (DR) on morphological choriocapillaris (CC) modifications in eyes with type 1 macular neovascularization (MNV) secondary to AMD using optical coherence tomography angiography (OCTA).
Methods
Eyes with AMD-related type 1 MNV with and without DR were prospectively included. We performed 3 × 3 mm OCTA scans at two visits: before the loading phase of intravitreal injections of aflibercept (T1) and 1 month after the last injection (T2). OCTA En face flow images of the CC were analyzed for flow deficit percentage (FD%), FD average area and FD number in a 500-µm-wide ring surrounding the dark halo (DH) around type 1 MNV.
Results
A total of 65 eyes, out of which 30 eyes had mild DR, were included. In the group without diabetes, there was a gradual reduction in FD% in the CC ring around the DH after antiangiogenic therapy, indicating reperfusion of the CC (P = 0.003). However, in the DR group, there were no significant changes in CC parameters between the two study visits. Specifically, the FD% in the CC ring around the DH did not show a significant reduction at T2 compared with T1 values (P > 0.05). Furthermore, the comparison of the variation in FD% between the two groups was statistically significant. The nondiabetic group exhibited a gradual CC reperfusion after the loading phase of aflibercept, whereas the diabetic eyes did not show significant changes (P = 0.029).
Conclusions
The CC surrounding the DH associated to type 1 MNV exhibited greater hypoperfusion in diabetic eyes compared with eyes without diabetes, both before starting therapy and after the loading phase. Hence, DR may be a potential risk factor in the development and progression of late-stage AMD and may also influence the response to antiangiogenic therapy.
Choroidal vessels account for 85% of all blood vessels in the eye, and the accurate segmentation of choroidal vessels from Optical Coherence Tomography (OCT) images provides important support for the quantitative analysis of choroid-related diseases and the development of treatment plans. Although deep learning-based methods have great potential for segmentation, these methods rely on large amounts of well-labeled data, and the data collection process is both time-consuming and laborious. Approach. In this paper, we propose a novel asymmetric semi-supervised segmentation framework called SSCR, based on a student-teacher model, to segment choroidal vessels in OCT images. The proposed framework enhances the segmentation results with uncertainty-aware self-integration and transformation consistency techniques. Meanwhile, we designed an asymmetric encoder-decoder network called Pyramid Pooling SegFormer (APP-SFR) for choroidal vascular segmentation. The network combines local attention and global attention information to improve the model's ability to learn complex vascular features. Additionally, we proposed a boundary repair module that enhances boundary confidence by utilizing a repair head to re-predict selected fuzzy points and further refines the segmentation boundary. Main results. We conducted extensive experiments on three different datasets: the ChorVessel dataset with 400 OCT images, the Meibomian Glands (MG) dataset with 400 images, and the U2OS Cell Nucleus Dataset with 200 images. The proposed method achieved an average Dice score of 74.23% on the ChorVessel dataset, which is 2.95% higher than the fully supervised network (U-Net) and outperformed other comparison methods. In both the MG dataset and the U2OS cell nucleus dataset, our proposed SSCR method achieved average Dice scores of 80.10% and 87.26%, respectively. Significance. The experimental results show that our proposed methods achieve better segmentation accuracy than other state-of-the-art methods. The method is designed to help clinicians make rapid diagnoses of ophthalmic diseases and has potential for clinical application.
Purpose
We hypothesize that OCTA-visualized vascular morphology may be a predictor of CNV status in AMD. We thus evaluated the use of AI to predict different stages of AMD disease based on OCTA en-face 2D projections scans.
Methods
Retrospective cross-sectional study based on collected 2D OCTA data from 310 high-resolution scans. Based on OCT B-scan fluid and clinical status, OCTA was classified as normal, dry AMD, wet AMD active and wet-AMD in remission with no signs of activity. Two human experts graded the same test set and a consensus grading between 2 experts was used for the prediction of 4 categories.
Results
The AI can achieve 80.36% accuracy on a four-category grading task with 2D OCTA projections. The sensitivity of prediction by AI was: 0.7857 (active), 0.7142 (remission), 0.9286 (dry AMD), and 0.9286 (normal) and the specificity was 0.9524, 0.9524, 0.9286, and 0.9524, respectively. The sensitivity of prediction by human experts was: 0.4286 active CNV, 0.2143 remission, 0.8571 dry AMD, and 0.8571 normal with specificity of 0.7619, 0.9286, 0.7857, 0.9762 respectively. The overall AI classification prediction was significantly better than the human (odds ratio=1.95, p=0.0021).
Conclusion
Our data shows that CNV morphology can be used to predict disease activity by AI; Longitudinal studies are needed to better understand the evolution of CNV and features that predict reactivation. Future studies will be able to evaluate the additional predicative value of OCTA on top of other imaging characteristics (i.e., fluid location on OCT B scans) to help predict response to treatment.
Purpose
To explore the predictive roles of the morphologic features of neovascularization in the prognosis of myopic choroidal neovascularization.
Methods
In this retrospective case series study, quantitative morphologic features of neovascularization were obtained from the optical coherence tomography angiography images. According to the number of anti-vascular endothelial growth factor injections administered within 1 year, the eyes were classified into a stable group (≤2 injections) or an unstable group (>2 injections). Best-corrected visual acuity was recorded before the treatment and at the 1-year follow-up.
Results
Overall, 50 eyes with treatment-naive myopic choroidal neovascularization were included; 26 in the stable group and 24 in the unstable group. Multivariate analysis showed that the eyes in the unstable group were associated with a larger lesion area (odds ratio = 2.596, P = 0.012), higher junction density (odds ratio = 1.611, P = 0.014), and higher end point density (odds ratio = 1.435, P = 0.023).The area under the receiver operating characteristic curve of the multivariate model was 0.865, with 91.7% sensitivity and 65.4% specificity. The final best-corrected visual acuity was significantly correlated with the lesion area (β = 0.152, P = 0.032) after adjusted for age, sex, and baseline best-corrected visual acuity.
Conclusion
Lesions with larger areas and higher end point and junction densities tended to have more frequent anti-vascular endothelial growth factor injections and worse visual outcomes in eyes with myopic choroidal neovascularization.
Objective:
To determine the correlation between contrast sensitivity and morphological characteristics obtained by Optical Coherence Tomography (OCT) in patients with Age-Related Macular Degeneration treated with a loading dose of vascular endothelial growth factor inhibitors (anti-VEGF).
Design:
This is an ambispective (prospective + retrospective) observational, cross-sectional, and analytical study PARTICIPANTS: All patients over 55 years of age with Age-Related Macular Degeneration who attended the Retina service of the Ophthalmology department and met the inclusion criteria between March- May 2022 METHODS: Data collection was carried out by reviewing the records of patients diagnosed with Age-Related Macular Degeneration of the neovascular variety treated with the loading dose of anti-VEGF. OCT studies obtained by Optovue® iVue80 prior to the application of intravitreal injections of patients who met the inclusion criteria and were currently in the first month after the last dose of anti-VEGF were analyzed. A total of 33 subjects were included, of which 30 continued follow-ups. The subjects underwent a new ophthalmological evaluation and new retinal measurements of the affected eye. Normality tests (Shapiro‒Wilk) were performed where a nonparametric data distribution was demonstrated.
Results:
A linear regression analysis was performed comparing the logarithmic values of both visual acuity and contrast sensitivity, obtaining a significant relationship between both values after the application of treatment (p=<0.0001***). Likewise, correlation was demonstrated between the decrease in contrast sensitivity values and all the characteristics evaluated in the patients' OCT.
Conclusions:
Antiangiogenesis strategies can lead to better results in global visual function, positively impacting contrast sensitivity.
This paper aims to present an artificial intelligence-based algorithm for the automated segmentation of Choroidal Neovascularization (CNV) areas and to identify the presence or absence of CNV activity criteria (branching, peripheral arcade, dark halo, shape, loop and anastomoses) in OCTA images. Methods: This retrospective and cross-sectional study includes 130 OCTA images from 101 patients with treatment-naïve CNV. At baseline, OCTA volumes of 6 × 6 mm2 were obtained to develop an AI-based algorithm to evaluate the CNV activity based on five activity criteria, including tiny branching vessels, anastomoses and loops, peripheral arcades, and perilesional hypointense halos. The proposed algorithm comprises two steps. The first block includes the pre-processing and segmentation of CNVs in OCTA images using a modified U-Net network. The second block consists of five binary classification networks, each implemented with various models from scratch, and using transfer learning from pre-trained networks. Results: The proposed segmentation network yielded an averaged Dice coefficient of 0.86. The individual classifiers corresponding to the five activity criteria (branch, peripheral arcade, dark halo, shape, loop, and anastomoses) showed accuracies of 0.84, 0.81, 0.86, 0.85, and 0.82, respectively. The AI-based algorithm potentially allows the reliable detection and segmentation of CNV from OCTA alone, without the need for imaging with contrast agents. The evaluation of the activity criteria in CNV lesions obtains acceptable results, and this algorithm could enable the objective, repeatable assessment of CNV features.
Introduction: Age-related macular degeneration (AMD) is a leading cause of visual impairment and severe vision loss, with the number of cases expected to increase because of the aging population. However, many aspects of AMD, including how it works and how it is treated, have yet to be elucidated. This study aims to identify and evaluate the global trends in AMD research over the last twenty years and visualize the frontiers using bibliometric analysis.
Methods: We collected all the publications on AMD from 2002 to 2021, analyzed trends within them, and defined the contributions of various countries/regions, institutions, core authors, and journals. Additionally, we used VOSviewer and CiteSpace software to combine networks and define the hot keywords in this field. AMD citation network was visualized using CitNetExplorer.
Results: In total, 16,145 publications on myopia were retrieved from 2001 to 2021. The United States has contributed the most publications (6,081) and the most citations (307,164). Holz FG contributed to the most publications, and Klein R had the most citations. Ophthalmology was the journal with the highest number of citations, and Investigative Ophthalmology & Visual Science had the maximum number of publications. The top 10 cited papers mainly focused on the therapeutic target. Keywords analysis and Citation network analysis were clustered into four groups: mechanisms, treatment, feature and classification, and prevalence, among which “mechanisms” was the largest cluster.
Conclusions: With the increasing prevalence of AMD, mechanisms for AMD control are a potential research hotspot and pressing public health issue. These results helped clarify the comprehensive research progress that has been made as well as the future trends in the study of AMD, which can assist and guide future research.
Background and objective:
The purpose of this article is to demonstrate the optical coherence tomography angiography (OCTA) Analysis Toolkit (OAT), a custom-designed software package, as a repeatable and reproducible tool for computing OCTA metrics across different devices.
Materials and methods:
Fourteen participants were imaged using three devices. Foveal avascular zone, vessel index, vessel length index, and vessel diameter index were calculated using the OAT. Repeatability and reproducibility were assessed using the coefficient of variation and interclass correlation coefficient (ICC).
Results:
Analysis of identical images demonstrated perfect levels of repeatability for all metrics (coefficient of variation 0%), which was a consequence of the software being deterministic (ie, producing the same outputs for the same inputs). Foveal avascular zone ICC values were in the excellent-to-good range (ICC > 0.6) for all devices. All values for vessel index (VI), vessel length index, and vessel diameter index fell in the good-to-fair (ICC > 0.4) or excellent-to-good range, except for vessel index analysis in the Cirrus device (ICC = 0.34).
Conclusions:
The OAT appears to be a reliable tool that may enable comparison between OCTA data sets acquired on different imaging instruments, thereby facilitating a more consistent approach to OCTA analysis. [Ophthalmic Surg Lasers Imaging Retina 2023;54:114-122.].
Purpose
To compare morphologic characteristics of type 1 macular neovascularization (MNV) flow pattern in treatment-naïve and previously treated patients with age-related macular degeneration (AMD) as assessed by optical coherence tomography angiography (OCTA).
Study Design
Cross-sectional study
Materials and Methods
Macular OCT angiography images were acquired using RTVue XR Avanti with AngioVue. Distinct morphologic biomarkers and quantifiable features of the neovascular membranes were studied on en-face projection images comparing treatment-naïve and previously treated patients.
Results
The study included 68 eyes of 58 patients. Among them, 24 eyes were treatment-naïve, and the remaining eyes had received a mean of 19.6 injections. Immature lesions were more associated with treatment-naïve eyes and hyper-mature lesions were associated with previously treated eyes (p = 0.005). Tangle pattern was associated with treatment-naïve eyes (p = 0.013), whereas mature core vessels and sea fan pattern were associated more with previously treated eyes (p = 0.001 and p = 0.044, respectively). Vascular density of the neovascular membrane was higher in the treatment-naïve group (p = 0.036) and the average MNV area was similar between the 2 groups (p = 0.683).
Conclusions
Based on OCTA, morphologic biomarkers of type 1 MNV might be an indication of previous treatment. The MNV pattern can improve our understanding of its maturation under anti-VEGF treatment and might be valuable to better guide therapeutic decisions and provide more personalized care to patients with AMD.
Purpose
β- thalassemia major causes hypoxia, which affects the retinal nerve fiber layer (RNFL), causing apoptosis. The frequent blood transfusion in transfusion-dependent thalassemia (TDT) accumulates ferritin, causing more damage. Using Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA), we aim to compare these changes in Youngs and adults.
Methods
In this cross-sectional non-randomized comparative study, 50 TDT patients were included: 28 were under 18 years (group1) and 22 were above 18 years (group2). They were subjected to hematological examination and ophthalmological examination, including OCT and OCTA. Then, the data were collected and analyzed.
Results
There was a statistical difference between the age in both groups (p=0.01). The two groups did not differ in sex distribution as well (p=0.085). All hematological parameters showed fewer values in (group 2) with a statistically significant difference in Serum ferritin, showing a marked increasing difference. There was a statistical difference between all Macular parameters and peripapillary quadrantal RNFL thickness of both groups (except for the C/D ratio), with higher values in (group 1). A moderate or strong positive correlation was found between all retinal parameters except for the C/D ratio and Hb level. A moderate or strong positive correlation was found between all retinal parameters except for the C/D ratio and serum ferritin. Moreover, there was a moderate to strong negative correlation between all retinal parameters except for the C/D ratio and frequency of blood transfusion.
Conclusion
patients above 18 years (group2) are more affected by more RNFL thinning and vascular density changes.
Purpose We sought to analyze quantitative data findings of optical coherence tomography angiography (OCTA) of different morphologies of macular neovascularization (MNV) in patients with neovascular age-related macular degeneration (nAMD) who received intravitreal conbercept (IVC) or ranibizumab (IVR).
Methods This was a prospective, interventional case series study and involved 39 patients, including 23 treated with 0.05 mL of conbercept and 16 treated with 0.05 mL of ranibizumab. Patients with MNV were diagnosed with nAMD for the first time at Shaanxi People's Hospital and all were treated with the "3 + PRN" regimen. These MNV cases could be further divided into four OCTA patterns: the “Medusa” pattern, the “tangled” pattern, the “seafan” pattern, and the “other” pattern. Patients were examined using OCTA before (T1) the injection and at 1 day (T2), 7 days (T3), 30 days (T4), 60 days (T5), and 90 days (T6) after anti–vascular endothelial growth factor (VEGF) treatments. Main outcome measures included best-corrected visual acuity (BCVA), MNV vascular area (MNV-VA), MNV vascular density ratio (MNV-VD ratio), and central macular thickness (CMT).
Results Forty-four eyes of 39 patients with nAMD (17 men and 22 women) were included. The average age of participants was 71.34 ± 10.34 years (range, 50–91 years). Twenty-eight eyes (23 patients) received IVC, and 18 eyes (16 patients) received IVR. At 90 days after treatment, the mean BCVAs of patients with the four patterns in the IVC group were improved (P = 0.002); notably, the tangled pattern patients had significantly better results than those with the other three patterns (P = 0.007). Eyes with all four patterns showed significant CMT decreases from the baseline level at 90 days, but there was no significant difference in the total change of CMT between the eyes with different patterns (P = 0.052). The mean MNV-VA and MNV-VD ratios were reduced in all four pattern groups, although the difference of the Medusa pattern was statistically significant for the mean MNV-VA (P = 0.008) but not the mean MNV-VD ratio (P = 0.107). In the IVR group, among the four patterns, the patients with the seafan MNV pattern showed a more significant BCVA improvement (P = 0.042). The mean CMTs of four MNV patterns were decreased after treatment, most notably in patients with the other pattern, but there was no significant difference (P = 0.114). Considering MNV parameters, the mean MNV-VA of the seafan pattern and the mean MNV-VD of the other pattern were significantly decreased, albeit without significant differences (P = 0.225 and P = 0.109). For the comparison between the 2 groups, the mean BCVA, CMT, and MNV parameters were all not significantly different between pre-injection and at the last visit (90 days) after injection.
Conclusions The distinct morphologies of MNV in nAMD patients can be identified and quantitatively analyzed by OCTA. These different patterns might be useful and instructive predictors for the prognosis of nAMD patients after anti-VEGF therapy. Conbercept for patients with the tangled MNV pattern and ranibizumab for patients with the seafan MNV pattern may be considered as therapeutics.
Trial registration number ChiCTR2200056961
Purpose:
To analyze the clinical features of refractory age-related macular degeneration patients associated with the response to three consecutive loading doses of anti-vascular endothelial growth factor.
Methods:
A retrospective chart review was performed on typical exudative age-related macular degeneration patients treated by three consecutive anti-vascular endothelial growth factor injections. The patients were divided into a group without residual fluid on optical coherence tomography images (Group 1) and a group with residual fluid (Group 2). We analyzed qualitative and quantitative morphologic features of optical coherence tomography and optical coherence tomography angiography. We performed univariate and multivariate logistic regression analyses to identify factors associated with the treatment response.
Results:
We enrolled a total of 90 patients (Group 1: n = 60, Group 2: n = 30). Under optical coherence tomography, the choroidal thickness differed significantly between groups 1 and 2 (246.60 ± 67.67 vs. 286.90 ± 40.92 µ m, P = 0.001). Under optical coherence tomography angiography, the presence of branching (48.3% vs. 73.3%, P = 0.024), loops (31.7% vs. 66.7%, P = 0.002), and a peripheral arcade (40.0% vs. 76.7%, P = 0.001) differed significantly. Logistic regression analysis showed that the initial CT (B = 0.012; P = 0.007), presence of loops (B = 1.289; P = 0.015), and peripheral arcade (B = 1.483; P = 0.008) significantly affected the anti-vascular endothelial growth factor treatment response.
Conclusion:
A thicker choroid and the presence of loops and a peripheral arcade were significantly associated with a poorer response to three loading anti-vascular endothelial growth factor injections in typical exudative age-related macular degeneration patients.
Background
To investigate the sensitivity and specificity of optical coherence tomography angiography (OCTA) versus dye angiography for detecting pachychoroid neovasculopathy (PNV) and to determine the morphological factors that affect PNV detection.
Methods
Patients with pachychoroid phenotype wereprospectively enrolled and underwent multimodal imaging examinations during the same visit. The diagnostic accuracy of fundus fluorescein angiography (FFA), FFA combined with indocyanine green angiography (ICGA) and OCTA for PNV was evaluated using multimodal imaging as the reference. Multimodal parameters of PNV were qualitatively and quantitatively assessed.
Results
PNV was detected in 58 eyes (46 patients) out of 340 pachychoroid eyes (201 patients) according to reference standard. Patients with PNV eyes were significantly older (54.6±7.56 vs. 48.2±9.1 years), were more likely to have a chronic central serous chorioretinopathy history (CSC) (93.1% vs. 12.4%) and had a worse visual acuity (0.30±0.22 vs. 0.58±0.30) than those without PNV eyes (all P<0.001). The sensitivity of FFA, FFA combined with ICGA, and OCTA in detecting PNV in patients with the pachychoroid phenotype was 67.2%, 63.8% and 98.3%, respectively, and the specificity was 87.2%, 96.8% and 100.0%, respectively. PNV not identified by dye angiography was more manifested as the absence of late plaque hypercyanescence on ICGA (P<0.001) and overall smaller capillaries without a distinct pattern (P=0.001), fewer core vessels (P=0.002) and smaller area (P=0.044).
Conclusions
OCTA showed superior detection rate and accuracy for identifying PNV over dye angiography. In case multimodal imaging is unavailable, OCTA can be an effective and noninvasive method for monitoring PNV and guiding treatment decisions.
Non-exudative macular and choroidal neovascularization (MNV and CNV) usually refers to the entity of treatment-naïve type 1 neovascularization in the absence of associated signs of exudation. Histopathological studies, dating back in the early 70s, identified the presence of non-exudative MNV, but the first clinical report of this finding was in the late 90s using indocyanine green angiography in eyes with age-related macular degeneration (AMD). With more advanced retinal imaging, there has been an ever increasing appreciation of non-exudative MNV associated with AMD and CNV with other macular disorders. However, consensus regarding the exact definition and the clinical management of this entity is lacking. Furthermore, there may be variation in the imaging features and clinical course suggesting that a spectrum of disease may exist. Herein, we review the large body of published work that has provided a better understanding of non-exudative MNV and CNV in the last decade. The prevalence, multimodal imaging features, clinical course, and response to treatment are discussed to elucidate further key insights about this entity. Based on these observations, this review also proposes a new theory about the origin and course of different sub-types of non-exudative MNV/CNV which can have different etiologies and pathways according to the clinical context of disease.
Purpose:
To identify baseline morphological predictors of lesion shrinkage in eyes with myopic choroidal neovascularization (mCNV) treated with anti-vascular endothelial growth factor (VEGF).
Methods:
This retrospective study included 46 eyes (41 consecutive patients) with active mCNV receiving anti-VEGF treatment. Optical coherence tomography angiography (OCTA) was performed at baseline and 1 year after treatment. Quantitative features were obtained from OCTA images using AngioTool software. Eyes were classified as "high-shrinkage" or "low-shrinkage" according to the median relative change in lesion area. Baseline quantitative morphological features associated with mCNV shrinkage were identified in univariate and multivariate analyses.
Results:
The mCNV area was significantly smaller after 1 year (P=0.013), with a median relative change of -16.5%. The relative change in mCNV area was -48.3% in high-shrinkage eyes (n=23) and -5.2% in low-shrinkage eyes (n=23). High-shrinkage eyes had a smaller mCNV area (P=0.013), shorter total vessel length (P=0.023), and higher endpoint density (P<0.001). Multivariate analysis showed significant associations of high shrinkage with endpoint density (β=-0.037, P=0.043) and previous anti-VEGF treatment (β=0.216, P=0.029).
Conclusion:
Morphological features of neovascularization detected by OCTA can predict lesion shrinkage in eyes with mCNV receiving anti-VEGF therapy. Higher endpoint density contributed to shrinkage, particularly of treatment-naive lesions.
Purpose
This work aims to review the principles of optical coherence tomography angiography (OCTA), to survey its clinical utility, and to highlight the strengths of this technology as well as barriers to adoption.
Methods
A literature review with editorial discussion of the current applications for OCTA is presented.
Results
There have been recent advances in multiple domains in OCTA imaging, including devices, algorithms, and new observations pertaining to a range of pathologies. New devices have improved the scanning speed, signal-to-noise ratio, and spatial resolution and offer an increased field of view. New algorithms have been proposed to optimize image processing and reduce artifacts. Numerous studies employing OCTA have been published describing changes to the microvasculature in diabetic retinopathy, age-related macular degeneration, central serous chorioretinopathy, retinal vein occlusion, and uveitis.
Conclusions
OCTA provides noninvasive, high-resolution volumetric scans of the retinal and choroidal vasculature. OCTA can provide valuable data to augment traditional dye-based angiography in a range of chorioretinal diseases.
Purpose This study aimed to determine the changes that occur in the vasculature, as based on optical coherence tomography angiography (OCTA) after non-damaging endpoint management (EpM), using a continuous wave yellow laser. The study was on eyes with diabetic macular edema (DME) that were resistant to anti-vascular endothelial growth factors (anti-VEGFs).
Materials and Methods This was a retrospective analysis of OCTA images of 44 eyes in 44 patients with DME refractory to anti-VEGF. The eyes were treated with a PASCAL Streamline yellow laser (577 nm wavelength, 200 mm spot size). Treatment was administered to the DME area and utilized 10% continuous wave laser energy and 0.50 µm beam diameter spot spacing. Best-corrected visual acuity (BCVA) and enhanced in-depth imaging with optical coherence tomography (EDI-OCT) and fundus autofluorescence (FAF) images were recorded at baseline, and 3 and 6 months posttreatment. Total choroidal area (TCA), luminal area (LA), stromal area (SA), and the choroidal vascularity index (CVI) were calculated using Image J software. The macula was divided into five quadrants in accordance with the mapping system in the Early Treatment Diabetic Retinopathy Study (ETDRS).
Results All patients (mean age: 58.90 ± 9.55 years) were diagnosed with diabetes mellitus type 2. Mean BCVA at baseline was 0.30 ± 0.11 logarithm of the minimum angle of resolution (logMAR) versus 0.23 ± 0.10 logMAR at 3 months (p = 0.032) and 0.17 ± 0.10 logMAR at 6 months (p = 0.013). The foveal avascular zone area (FAZ) decreased in the deep capillary plexus (DCP) from baseline to 6 months (p = 0.028). Vessel densities (VDs) of the superficial capillary plexus (SCP), DCP, and choriocapillaris decreased significantly in the fovea at 3 and 6 months compared to baseline (p < 0.05 for both follow-up time points). There were significant decreases in SCP and DCP in the superior quadrant at the end of month 6 (p = 0.001 and p = 0.038, respectively). There was a significant decrease in the nasal quadrant of the DCP and choriocapillaris at the end of month 6 (p = 0.024 and p = 0.049, respectively). Although there was a significant decrease in central macular thickness (CMT) (p < 0.001), subfoveal choroidal thickness (SFCT) (p < 0.001), and LA (p = 0.034) at months 3 and 6, there was no significant change in the CVI (p = 0.19). According to the DME recovery rate, 36 eyes (81%) were irradiated once, whereas 8 eyes (19%) were irradiated twice.
Conclusions Non-damaging EpM therapy using a continuous wave yellow laser in eyes with DME that are resistant to anti-VEGFs induces significant changes in the SCP, choriocapillaris, and, most commonly, the DCP, which caused a significant decrease in VDs during 6 months of follow-up.
Background
Neovascular age-related macular degeneration is a leading cause of sight loss, and early detection and treatment is important. For patients with neovascular age-related macular degeneration in one eye, it is usual practice to monitor the unaffected eye. The test used to diagnose neovascular age-related macular degeneration, fundus fluorescein angiography, is an invasive test. Non-invasive tests are available, but their diagnostic accuracy is unclear.
Objectives
The primary objective was to determine the diagnostic monitoring performance of tests for neovascular age-related macular degeneration in the second eye of patients with unilateral neovascular age-related macular degeneration. The secondary objectives were the cost-effectiveness of tests and to identify predictive factors of developing neovascular age-related macular degeneration.
Design
This was a multicentre, prospective, cohort, comparative diagnostic accuracy study in a monitoring setting for up to 3 years. A Cox regression risk prediction model and a Markov microsimulation model comparing cost-effectiveness of the index tests over 25 years were used.
Setting
This took place in hospital eye services.
Participants
Participants were adults (aged 50–95 years) with newly diagnosed (within the previous 6 weeks) neovascular age-related macular degeneration in one eye and an unaffected second (study) eye who were attending for treatment injections in the first eye and who had a study eye baseline visual acuity of ≥ 68 Early Treatment Diabetic Retinopathy Study letters.
Interventions
The index tests were Amsler chart (completed by participants), fundus clinical examination, optical coherence tomography, self-reported vision assessment (completed by participants) and visual acuity. The reference standard was fundus fluorescein angiography.
Main outcome measures
The main outcome measures were sensitivity and specificity; the performance of the risk predictor model; and costs and quality-adjusted life-years.
Results
In total, 552 out of 578 patients who consented from 24 NHS hospitals ( n = 16 ineligible; n = 10 withdrew consent) took part. The mean age of the patients was 77.4 years (standard deviation 7.7 years) and 57.2% were female. For the primary analysis, 464 patients underwent follow-up fundus fluorescein angiography and 120 developed neovascular age-related macular degeneration on fundus fluorescein angiography. The diagnostic accuracy [sensitivity (%) (95% confidence interval); specificity (%) (95% confidence interval)] was as follows: optical coherence tomography 91.7 (85.2 to 95.6); 87.8 (83.8 to 90.9)], fundus clinical examination [53.8 (44.8 to 62.5); 97.6 (95.3 to 98.9)], Amsler [33.7 (25.1 to 43.5); 81.4 (76.4 to 85.5)], visual acuity [30.0 (22.5 to 38.7); 66.3 (61.0 to 71.1)] and self-reported vision [4.2 (1.6 to 9.8); 97.0 (94.6 to 98.5)]. Optical coherence tomography had the highest sensitivity across all secondary analyses. The final prediction model for neovascular age-related macular degeneration in the non-affected eye included smoking status, family history of neovascular age-related macular degeneration, the presence of nodular drusen with or without reticular pseudodrusen, and the presence of pigmentary abnormalities [ c -statistic 0.66 (95% confidence interval 0.62 to 0.71)]. Optical coherence tomography monitoring generated the greatest quality-adjusted life-years gained per patient (optical coherence tomography, 5.830; fundus clinical examination, 5.787; Amsler chart, 5.736, self-reported vision, 5.630; and visual acuity, 5.600) for the lowest health-care and social care costs (optical coherence tomography, £19,406; fundus clinical examination, £19,649; Amsler chart, £19,751; self-reported vision, £20,198; and visual acuity, £20,444) over the lifetime of the simulated cohort. Optical coherence tomography dominated the other tests or had an incremental cost-effectiveness ratio below the accepted cost-effectiveness thresholds (£20,000) across the scenarios explored.
Limitations
The diagnostic performance may be different in an unselected population without any history of neovascular age-related macular degeneration; the prediction model did not include genetic profile data, which might have improved the discriminatory performance.
Conclusions
Optical coherence tomography was the most accurate in diagnosing conversion to neovascular age-related macular degeneration in the fellow eye of patients with unilateral neovascular age-related macular degeneration. Economic modelling suggests that optical coherence tomography monitoring is cost-effective and leads to earlier diagnosis of and treatment for neovascular age-related macular degeneration in the second eye of patients being treated for neovascular age-related macular degeneration in their first eye.
Future work
Future works should investigate the role of home monitoring, improved risk prediction models and impact on long-term visual outcomes.
Study registration
This study was registered as ISRCTN48855678.
Funding
This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 26, No. 8. See the NIHR Journals Library website for further project information.
Purpose:
To evaluate eyes with age-related macular degeneration and high-risk characteristics for choroidal neovascularization (CNV) with optical coherence tomographic (OCT) angiography to determine whether earlier detection of CNV is possible.
Methods:
Eyes with drusen, pigmentary changes, and with CNV in the fellow eye were scanned with a 70-kHz spectral domain OCT system (Optovue RTVue-XR Avanti). The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to distinguish blood flow from static tissue. Two masked graders reviewed scans for CNV, defined as flow in the outer retinal/sub-RPE slab. Choroidal neovascularization flow area repeatability and between-grader reproducibility were calculated.
Results:
Of 32 eyes, 2 (6%) were found to have Type 1 CNV with OCT angiography. The lesions were not associated with leakage on fluorescein angiography or fluid on OCT. One case was followed for 8 months without treatment, and the CNV flow area enlarged slightly without fluid buildup on OCT or vision loss. Between-grader reproducibility of the CNV flow area was 9.4% (coefficient of variation) and within-visit repeatability was 5.2% (pooled coefficient of variation).
Conclusion:
Optical coherence tomographic angiography can detect the presence of nonexudative CNV, lesions difficult to identify with fluorescein angiography and OCT. Further study is needed to understand the significance and natural history of these lesions.
We demonstrate in vivo choriocapillaris and choroidal microvasculature imaging in normal human subjects using optical coherence tomography (OCT). An ultrahigh speed swept source OCT prototype at 1060 nm wavelengths with a 400 kHz A-scan rate is developed for three-dimensional ultrahigh speed imaging of the posterior eye. OCT angiography is used to image three-dimensional vascular structure without the need for exogenous fluorophores by detecting erythrocyte motion contrast between OCT intensity cross-sectional images acquired rapidly and repeatedly from the same location on the retina. En face OCT angiograms of the choriocapillaris and choroidal vasculature are visualized by acquiring cross-sectional OCT angiograms volumetrically via raster scanning and segmenting the three-dimensional angiographic data at multiple depths below the retinal pigment epithelium (RPE). Fine microvasculature of the choriocapillaris, as well as tightly packed networks of feeding arterioles and draining venules, can be visualized at different en face depths. Panoramic ultra-wide field stitched OCT angiograms of the choriocapillaris spanning ∼32 mm on the retina show distinct vascular structures at different fundus locations. Isolated smaller fields at the central fovea and ∼6 mm nasal to the fovea at the depths of the choriocapillaris and Sattler's layer show vasculature structures consistent with established architectural morphology from histological and electron micrograph corrosion casting studies. Choriocapillaris imaging was performed in eight healthy volunteers with OCT angiograms successfully acquired from all subjects. These results demonstrate the feasibility of ultrahigh speed OCT for in vivo dye-free choriocapillaris and choroidal vasculature imaging, in addition to conventional structural imaging.
Detailed visualization of microvascular changes in the human retina is clinically limited by the capabilities of angiography imaging, a 2D fundus photograph that requires an intravenous injection of fluorescent dye. Whereas current angiography methods enable visualization of some retinal capillary detail, they do not adequately reveal the choriocapillaris or other microvascular features beneath the retina. We have developed a noninvasive microvascular imaging technique called phase-variance optical coherence tomography (pvOCT), which identifies vasculature three dimensionally through analysis of data acquired with OCT systems. The pvOCT imaging method is not only capable of generating capillary perfusion maps for the retina, but it can also use the 3D capabilities to segment the data in depth to isolate vasculature in different layers of the retina and choroid. This paper demonstrates some of the capabilities of pvOCT imaging of the anterior layers of choroidal vasculature of a healthy normal eye as well as of eyes with geographic atrophy (GA) secondary to age-related macular degeneration. The pvOCT data presented permit digital segmentation to produce 2D depth-resolved images of the retinal vasculature, the choriocapillaris, and the vessels in Sattler's and Haller's layers. Comparisons are presented between en face projections of pvOCT data within the superficial choroid and clinical angiography images for regions of GA. Abnormalities and vascular dropout observed within the choriocapillaris for pvOCT are compared with regional GA progression. The capability of pvOCT imaging of the microvasculature of the choriocapillaris and the anterior choroidal vasculature has the potential to become a unique tool to evaluate therapies and understand the underlying mechanisms of age-related macular degeneration progression.
To analyze the internal structure of fibrovascular pigment epithelial detachment (FV-PED) due to AMD using en face enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT).
Thirty-eight consecutive patients presenting with FV-PED due to AMD were enrolled in this study. Retinal images were automatically obtained with a spectral domain (SD) OCT instrument; the typical inverted 97 sections at 30-μm intervals, each comprised of nine averaged B-scans, were acquired in less than 60 seconds. The resultant images of en face cross-sections of the choroid (C-scans) were compared with indocyanine green angiography (ICGA) images, currently the only technique available for directly viewing occult choroidal neovascularization (CNV).
Thirty-eight eyes of 38 consecutive patients (27 females and 11 males, mean age 76.7±3 years) were studied. In all 38 eyes, ICGA allowed visualization of the CNV within the FV-PED. In 30 eyes, en face EDI-OCT revealed what appeared to be the hyperreflective course of presumed CNV, which was located just beneath the detached retinal pigment epithelium; this was confirmed by comparative analysis of the extent of hyperreflective lesions on en face EDI-OCT images and that of the neovascular network on ICGA. An area of homogeneous hyporeflectivity, consistent with serous exudation, separated the CNV from the Bruch's membrane and the choroid. In the remaining eight eyes, en face EDI-OCT revealed homogenous hyperreflectivity, consistent with fibrous tissue that partially hid the neovascular network.
Noninvasive en face EDI-OCT technique enables visualization and localization of the entire branching neovascular network of CNV within FV-PED without dye injection.
To compare the utility of fluorescein angiography (FA) and optical coherence tomography (OCT) as diagnostic adjuncts in evaluating symptomatic patients with choroidal neovascularisation (CNV) due to multifocal choroiditis (MFC).
Patients with CNV due to MFC were retrospectively evaluated in a consecutive fashion. Fundus photography, FA, OCT and biomicroscopy were used to establish the diagnosis. Primary outcome measures included CNV classification (type 1 or occult and type 2 or classic) location and the associated FA and OCT findings.
Twenty eyes from 17 patients were included in the study. In 19 eyes (95%) the FA revealed CNV type 2; in one eye (5%) the type of CNV was indeterminate due to a subretinal haemorrhage that covered the lesion. Thirteen eyes had OCT imaging and all revealed hyper-reflectance beneath the neurosensory retina. However, only 53.8% revealed subretinal fluid (SRF) or intraretinal cystic abnormalities.
The CNV in MFC is virtually always type 2, or so-called classic CNV, with vessels beneath the neurosensory retina. Except when blocked by subretinal blood, the neovascularisation is clearly demonstrated by FA. In contrast, only 53.8% of these eyes showed clear evidence of actively proliferating neovascularisation on OCT. Therefore, eyes suspected of having CNV in MFC should be evaluated with FA.
In this study, the authors sought to develop and characterize techniques for measuring changes in choroidal neovascularization (CNV) lesion size and fluorescence over time for quantitative analysis of fluorescein angiograms.
Initial assessment of the quantitative technique was made by retrospectively analyzing digital fluorescein angiograms taken before and 3 months after photodynamic therapy (PDT) for CNV (6 patients, group 1). The method was then applied prospectively to digital fluorescein angiograms (baseline and day 71) obtained on 12 patients taking part in a clinical trial investigating the effect of vascular endothelial growth factor (VEGF) Trap in CNV (group 2). Two masked observers, with the use of image processing, measured the area of hyperfluorescence and fluorescence intensity above background. Values for each image were plotted against time after dye injection to generate curves, and each area under the curve (AUC) was calculated.
The physician who treated the patients in group 1 judged the condition of three patients to be improved and of three to be worse 3 months after PDT. Masked retrospective grading of fluorescein angiograms showed an 11% decrease in AUC for fluorescence area and a 32% decrease in AUC for fluorescence intensity in the three patients whose conditions clinically improved but increases of 131% and 292% in the three patients whose conditions clinically worsened. In group 2, a 38% decrease in AUC for fluorescence intensity and a 19% decrease in AUC for fluorescence area were observed in patients who received VEGF Trap compared with increases of 66% (P = 0.004, Mann-Whitney U test) and 21% (P = 0.07) for patients who received placebo. Macular volume decreased by 11% in VEGF Trap-treated patients and increased by 10% in placebo-treated patients (P = 0.03).
This study reports a technique for analysis of change in fluorescence area and intensity over time during fluorescein angiography (FA) using a continuous scale and its application in a clinical setting and a clinical trial. Compared with previous techniques making use of categorical scales, this approach provides an advantage for evaluating responses to treatment that may improve the value of FA as an outcome measure in clinical trials.
To compare the volume of various spaces visible on optical coherence tomography (OCT) images in different angiographic lesion subtypes of neovascular age-related macular degeneration (AMD).
Sixty-six cases of previously untreated, active subfoveal choroidal neovascularization (CNV) associated with AMD were retrospectively collected. CNV lesions were classified as occult with no classic CNV, minimally classic CNV, predominantly classic CNV, or CNV lesions with associated retinal angiomatous proliferation (RAP). Corresponding OCT image sets were analyzed by trained graders using previously validated custom software that allows manual placement of boundaries on OCT B-scans. Spaces delineated by these boundaries included the neurosensory retina, subretinal fluid, subretinal tissue, and pigment epithelial detachments (PEDs). Volume measurements were calculated by the software and compared among groups.
Minimally and predominantly classic CNV membranes demonstrated subretinal tissue on OCT in all cases and appeared to show a significantly greater volume of subretinal tissue than did the occult membranes. Subretinal fluid was present in all the predominantly classic cases. A PED was visible in all the occult CNV cases in our study, demonstrating less retinal thickening and significantly greater PED volumes than minimally and predominantly classic CNV lesions. Lesions associated with RAP showed the highest percentage of cystoid spaces.
OCT and angiography provide complementary information regarding CNV lesions. Quantitative analysis of OCT images allows for an improved understanding of the anatomic characteristics of angiographically defined CNV lesion subtypes.
Age-related macular degeneration is a progressive degenerative eye condition that causes painless loss of central vision in those aged 55 years or over. It is a disease normally associated with the elderly, and is therefore a growing problem worldwide due to our ageing population. The cause is suspected to be multi-factorial and no cure has been found. However, there are novel treatments available that can help delay its progression.
To characterize en face features of the retinal pigment epithelium (RPE) and choroid in eyes with chronic central serous chorioretinopathy (CSCR) using a high-speed, enhanced-depth swept-source optical coherence tomography (SS-OCT) prototype.
Consecutive patients with chronic CSCR were prospectively examined with SS-OCT.
Fifteen eyes of 13 patients.
Three-dimensional 6×6 mm macular cube raster scans were obtained with SS-OCT operating at 1050 nm wavelength and 100 000 A-lines/sec with 6 μm axial resolution. Segmentation of the RPE generated a reference surface; en face SS-OCT images of the RPE and choroid were extracted at varying depths every 3.5 μm (1 pixel). Abnormal features were characterized by systematic analysis of multimodal fundus imaging, including color photographs, fundus autofluorescence, fluorescein angiography, and indocyanine-green angiography (ICGA).
En face SS-OCT morphology of the RPE and individual choroidal layers.
En face SS-OCT imaging at the RPE level revealed absence of signal corresponding to RPE detachment or RPE loss in 15 of 15 (100%) eyes. En face SS-OCT imaging at the choriocapillaris level showed focally enlarged vessels in 8 of 15 eyes (53%). At the level of Sattler's layer, en face SS-OCT documented focal choroidal dilation in 8 of 15 eyes (53%) and diffuse choroidal dilation in 7 of 15 eyes (47%). At the level of Haller's layer, these same features were observed in 3 of 15 eyes (20%) and 12 of 15 eyes (80%), respectively. In all affected eyes, these choroidal vascular abnormalities were seen just below areas of RPE abnormalities. In 2 eyes with secondary choroidal neovascularization (CNV), distinct en face SS-OCT features corresponded to the neovascular lesions.
High-speed, enhanced-depth SS-OCT at 1050 nm wavelength enables the visualization of pathologic features of the RPE and choroid in eyes with chronic CSCR not usually appreciated with standard spectral domain (SD) OCT. En face SS-OCT imaging seems to be a useful tool in the identification of CNV without the use of angiography. This in vivo documentation of the RPE and choroidal vasculature at variable depths may help elucidate the pathophysiology of disease and can contribute to the diagnosis and management of chronic CSCR.
Proprietary or commercial disclosure may be found after the references.
Phase-variance optical coherence tomography (PV-OCT) provides volumetric imaging of the retinal vasculature without the need for intravenous injection of a fluorophore. We compare images from PV-OCT and fluorescein angiography (FA) for normal individuals and patients with age-related macular degeneration (AMD) and diabetic retinopathy.
This is an evaluation of a diagnostic technology.
Four patients underwent comparative retinovascular imaging using FA and PV-OCT. Imaging was performed on 1 normal individual, 1 patient with dry AMD, 1 patient with exudative AMD, and 1 patient with nonproliferative diabetic retinopathy.
Fluorescein angiography imaging was performed using a Topcon Corp (Tokyo, Japan) (TRC-50IX) camera with a resolution of 1280 (H) × 1024 (V) pixels. The PV-OCT images were generated by software data processing of the entire cross-sectional image from consecutively acquired B-scans. Bulk axial motion was calculated and corrected for each transverse location, reducing the phase noise introduced from eye motion. Phase variance was calculated through the variance of the motion-corrected phase changes acquired within multiple B-scans at the same position. Repeating these calculations over the entire volumetric scan produced a 3-dimensional PV-OCT representation of the vasculature.
Feasibility of rendering retinal and choroidal microvasculature using PV-OCT was compared qualitatively with FA, the current gold standard for retinovascular imaging.
Phase-variance OCT noninvasively rendered a 2-dimensional depth color-coded vasculature map of the retinal and choroidal vasculature. The choriocapillaris was imaged with better resolution of microvascular detail using PV-OCT. Areas of geographic atrophy and choroidal neovascularization imaged by FA were depicted by PV-OCT. Regions of capillary nonperfusion from diabetic retinopathy were shown by both imaging techniques; there was not complete correspondence between microaneurysms shown on FA and PV-OCT images.
Phase-variance OCT yields high-resolution imaging of the retinal and choroidal microvasculature that compares favorably with FA.
Proprietary or commercial disclosure may be found after the references.
Purpose of review:
To highlight the most common methods that are used to detect new-onset choroidal neovascularization (CNV) as a result of age-related macular degeneration (AMD).
Recent findings:
Numerous modalities are available to try to detect CNV. Amsler grid testing, preferential hyperacuity perimetry (PHP), optical coherence tomography (OCT), and fluorescein angiography are tools that may be used to detect CNV. The Age-Related Macular Degeneration: Detection of Onset of new Choroidal neovascularization Study (AMD DOC Study) evaluated the sensitivity of time domain OCT, relative to fluorescein angiography, in detecting new-onset neovascular AMD within a 2-year period. The sensitivity of each modality for detecting CNV was OCT 0.40 [(95% confidence interval (95% CI) (0.16-0.68), supervised Amsler grid 0.42 (95% CI 0.15-0.72), and PHP 0.50 (95% CI 0.23-0.77)].
Summary:
Numerous modalities are available to try to detect CNV. The prospective AMD DOC Study demonstrated that fluorescein angiography still remains the best method to detect new-onset CNV.
To determine the sensitivity of time domain optical coherence tomography (OCT) in detecting conversion to neovascular age-related macular degeneration (AMD) in eyes at high risk for choroidal neovascularization (CNV), compared with detection using fluorescein angiography (FA) as the gold standard.
Prospective, multicenter, observational study.
Individuals aged ≥50 years with nonneovascular AMD at high risk of progressing to CNV in the study eye and evidence of neovascular AMD in the fellow eye.
At study entry and every 3 months through 2 years, participants underwent best-corrected visual acuity, supervised Amsler grid testing, preferential hyperacuity perimetry (PHP) testing, stereoscopic digital fundus photographs with FA, and OCT imaging. A central Reading Center graded all images.
The sensitivity of OCT in detecting conversion to neovascular AMD by 2 years, using FA as the reference standard. Secondary outcomes included comparison of sensitivity, specificity, positive predictive value, and negative predictive value of OCT, PHP, and supervised Amsler grid relative to FA for detecting incident CNV.
A total of 98 participants were enrolled; 87 (89%) of these individuals either completed the 24-month visit or exited the study after developing CNV. Fifteen (17%) study eyes had incident CNV confirmed on FA by the Reading Center. The sensitivity of each modality for detecting CNV was: OCT 0.40 (95% confidence interval [CI], 0.16-0.68), supervised Amsler grid 0.42 (95% CI, 0.15-0.72), and PHP 0.50 (95% CI, 0.23-0.77). Treatment for incident CNV was recommended by the study investigator in 13 study eyes. Sensitivity of the testing modalities for detection of CNV in these 13 eyes was 0.69 (95% CI, 0.39-0.91) for OCT, 0.50 (95% CI, 0.19-0.81) for supervised Amsler grid, and 0.70 (95% CI, 0.35-0.93) for PHP. Specificity of the OCT was higher than that of the Amsler grid and PHP.
Time-domain OCT, supervised Amsler grid, and PHP have low to moderate sensitivity for detection of new-onset CNV compared with FA. Optical coherence tomography has greater specificity than Amsler grid or PHP. Among fellow eyes of individuals with unilateral CNV, FA remains the best method to detect new-onset CNV.
To evaluate the diagnostic characteristics of type 2 (classic) choroidal neovascularizations secondary to age-related macular degeneration using spectral domain-optical coherence tomography (SD OCT), indocyanine green angiography (ICGA), and fluorescein angiography (FA).
Observational case series.
Institutional.
Thirteen treatment-naïve eyes with type 2 choroidal neovascularization without an occult component.
Greatest horizontal dimension, based on the anatomic features of the neovascular complex by SD OCT (Spectralis; Heidelberg Engineering), ICGA, and FA; retinal leakage area in late-phase FA and ICGA; and the area of retinal edema in SD OCT.
For direct comparison, ICGA and FA images were overlaid manually on infrared plus SD OCT images using VirtualDub and Paint.NET software. Greatest horizontal dimension was measured using Image J software (National Institutes of Health).
The mean greatest horizontal dimension of the neovascular complex and the retinal leakage area consistently were smaller on ICGA compared with the area of retinal edema on SD OCT. According to FA, the greatest horizontal dimension of early, well-demarcated hyperfluorescence was significantly smaller than the neovascular complex on SD OCT. In addition, the greatest horizontal dimension of the retinal leakage area in late-phase FA consistently was smaller than the area of retinal edema on SD OCT.
In classic choroidal neovascularization, ICGA and FA seem to underestimate the extension of the neovascular complex and the associated retinal pathologic features compared with SD OCT imaging.
To evaluate spectral-domain optical coherence tomography (SD-OCT) findings that predict angiographic leakage in choroidal neovascularization (CNV).
SD-OCT and fluorescein angiography (FA) images of 93 eyes of 93 patients were retrospectively analyzed. All patients were previously treated with anti-vascular endothelial growth factor agents for CNV from age-related macular degeneration. FA images were analyzed to assess the presence of leakage. SD-OCT images were analyzed to identify the overall presence of fluid, as well as specific patterns of fluid presentation, including intraretinal cystic spaces (ICS), retinal pigment epithelium detachment (PED), and neurosensory detachment (NSD). The presence of ultrastructural features such as intraretinal hyperreflective flecks and the inherent reflectivity and boundary definition of the subretinal material were evaluated. Both the association and the sensitivity, specificity, and both positive and negative predictive values of SD-OCT findings compared with FA leakage were calculated.
A statistically significant association between SD-OCT findings and FA leakage was found for eyes that displayed fluid, NSD, intraretinal flecks, and low reflectivity or undefined boundaries from subretinal material, and not for PED or ICS. Sensitivity and specificity for SD-OCT findings were, respectively: 94% and 27% for fluid; 68% and 88% for NSD; 81% and 83% for intraretinal flecks; 63% and 92% for undefined boundaries of subretinal material; and 94% and 87% for low reflectivity from subretinal material.
The evidence of fluid on SD-OCT is sensitive but nonspecific in identifying FA leaky CNV. The assessment of neurosensory detachment as well as other ultrastructural elements may increase the specificity of analysis.
To correlate the volume of various spaces on optical coherence tomography (OCT) with fluorescein angiographic (FA) parameters in neovascular age-related macular degeneration (AMD).
Sixty-five consecutive cases of active subfoveal choroidal neovascularization (CNV) associated with AMD were retrospectively collected. Area and greatest linear dimension of CNV lesion components were calculated on FA. Corresponding StratusOCT image sets were analyzed using custom software (termed OCTOR), which allows manual measurement of the volume of the neurosensory retina, subretinal fluid, subretinal tissue, and pigment epithelial detachment (PED).
Area of occult CNV on FA correlated with PED (R = 0.62) and subretinal fluid (R = 0.28) volume and negatively with subretinal tissue volume (R = -0.26) on OCT. Area of classic CNV on FA correlated with subretinal tissue (R = 0.60) and retinal (R = 0.38) volume on OCT. Automated StratusOCT output values showed poorer correlations than manually calculated OCTOR values.
OCT features of CNV lesions as measured by manual quantitative subanalysis correlate better with angiographic parameters than values provided by the automated StratusOCT analysis. These measures may improve our understanding of the morphologic effects of CNV lesions and may facilitate the development of a hybrid FA and OCT-based classification system for future clinical trials, which more fully characterizes CNV lesions.
Intravenous fluorescein angiography is a commonly performed and extraordinarily valuable diagnostic procedure. The frequency of adverse reactions after angiography has varied considerably in previous reports. In a prospective study of 2789 angiographic procedures in 2025 patients, the authors found that the percentage of adverse reactions depended strongly on the patient's angiographic history. Overall, adverse reactions followed 4.8% of the angiographic procedures. These reactions included nausea (2.9%), vomiting (1.2%), flushing/itching/hives (0.5%), and other reactions (dyspnea, syncope, excessive sneezing) (0.2%). No cases of anaphylaxis, myocardial infarction, pulmonary edema, or seizures occurred. The percentage of reactions was 1.8% for patients who had had previous angiography without ever having had an adverse reaction. In contrast, the percentage of reactions was 48.6% for patients who had had an adverse reaction to angiography previously.
Adverse reactions following intravenous sodium fluorescein are very unusual and their mechanism is still uncertain. We report the case of a patient who suffered an adverse reaction during a fluorescein ocular angiography. Positive allergy tests to fluorescein suggest an IgE-mediated mechanism.
Report the allergy evaluation performed in a patient who suffered an adverse reaction during an intravenous fluorescein administration.
We selected the case of a patient who suffered dizziness, diaphoresis, generalized pallor, nausea, sphincter relaxation, hypotension, and intense malaise during a fluorescein ocular angiography and compared the results to other nonreactive subjects. Allergy evaluation: Prick and intradermal skin tests and serial determinations of serum tryptase were performed on the patient and four control subjects who underwent and tolerated the same procedure as well as on a patient who developed an intense vagal reaction during blood extraction.
Positive skin tests and dramatic increase of serum tryptase (67U/I) were observed in our patient. The rest of the patients had negative skin tests and did not have any variation in their serum tryptase.
An IgE-mediated mechanism is suggested as responsible for this adverse reaction. We recommend that a complete allergy evaluation should be performed in all patients who have adverse reactions to fluorescein in order to differentiate true allergic reactions from other types of reactions.
It is known that choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) may erode through the retinal pigment epithelium, infiltrate the neurosensory retina, and communicate with the retinal circulation in what has been referred to as a retinal-choroidal anastomosis (RCA). This is extremely common in the end stage of disciform disease. In recent years, the reverse also seems to be possible, as angiomatous proliferation originates from the retina and extends posteriorly into the subretinal space, eventually communicating in some cases with choroidal new vessels. This form of neovascular ARMD, termed retinal angiomatous proliferation (RAP) in this article, can be confused with CNV.
The purpose of this article is 1) to review the clinical and angiographic characteristics of a series of patients with RAP and 2) to propose a theoretical sequence of events that accounts for the neovascularized process.
In this retrospective clinical and angiographic analysis, 143 eyes with RAP (108 patients) were reviewed and classified based on their vasogenic nature and course. Clinical biomicroscopic examination, fluorescein angiography, and indocyanine green angiography were used to evaluate patients.
The results of this series suggest that angiomatous proliferation within the retina is the first manifestation of the vasogenic process in this form of neovascular ARMD. Dilated retinal vessels and pre-, intra-, and subretinal hemorrhages and exudate evolve, surrounding the angiomatous proliferation as the process extends into the deep retina and subretinal space. One or more dilated compensatory retinal vessels perfuse and drain the neovascularization, sometimes forming a retinal-retinal anastomosis. Fluorescein angiography in these patients usually revealed indistinct staining simulating occult CNV. Indocyanine green angiography was useful to make an accurate diagnosis in most cases. It revealed a focal area of intense hyperfluorescence corresponding to the neovascularization ("hot spot") and other characteristic findings. Based on understanding of the nature and progression of the neovascularized process, patients with RAP were classified into three vasogenic stages. Stage I involved proliferation of intraretinal capillaries originating from the deep retinal complex (intraretinal neovascularization [IRN]). Stage II was determined by growth of the retinal vessels into the subretinal space (subretinal neovascularization [SRN]). Stage III occurred when CNV could clearly be determined clinically or angiographically. A vascularized pigment epithelial detachment and RCA were inconsistent features of this stage.
Retinal angiomatous proliferation appears to be a distinct subgroup of neovascular ARMD. It may present in one of three vasogenic stages: IRN, SRN, or CNV. Whereas ICG angiography is helpful in diagnosing RAP and in documenting the stage of the neovascularized process, it is frequently difficult to determine the precise nature and location of the new vessel formation. It is important for clinicians to recognize the vasogenic potential and the associated manifestations of this peculiar form of neovascular ARMD so that a proper diagnosis can be made, and when possible, an appropriate management administered.
Age-related macular degeneration is the principal cause of registered legal blindness among those aged over 65 in the United States, western Europe, Australia, and Japan. Despite intensive research, the precise etiology of molecular events that underlie age-related macular degeneration is poorly understood. However, investigations on parallel fronts are addressing this prevalent public health problem. Sophisticated biochemical and biophysical techniques have refined our understanding of the pathobiology of drusen, geographic atrophy, and retinal pigment epithelial detachments. Epidemiological identification of risk factors has facilitated an intelligent search for underlying mechanisms and fueled clinical investigation of behavior modification. Gene searches have not only brought us to the cusp of identifying the culpable gene loci in age-related macular degeneration, but also localized genes responsible for other macular dystrophies. Recent and ongoing investigations, often cued by tumor biology, have revealed an important role for various growth factors, particularly in the neovascular form of the condition. Transgenic and knockout studies have provided important mechanistic insights into the development of choroidal neovascularization, the principal cause of vision loss in age-related macular degeneration. This in turn has culminated in preclinical and clinical trials of directed molecular interventions.
New England Eye Center at Tufts Medical Center, 260 Tremont Street, Biewend Building, 9-11th Floor
- Nadia K Waheed
- Md
- Mph
Nadia K. Waheed, MD, MPH, New England Eye Center at Tufts Medical
Center, 260 Tremont Street, Biewend Building, 9-11th Floor, Boston,
MA 02116. E-mail: nadiakwaheed@gmail.com.
Relationship between angiographic and optical coherence tomographic (OCT) parameters for quantifying choroidal neovascular lesions.
- Sadda S.R.
- Liakopolous S.
- Keane P.A.
Sadda SR, Liakopolous S, Keane PA, et al. Relationship between angiographic and optical coherence tomographic (OCT)
parameters for quantifying choroidal neovascular lesions.
Graefes Arch Clin Exp Ophthalmol 2010;248:175-84.
Optical imaging of the chorioretinal vasculature in the living human eye.
- Kim D.Y.
- Finger J.
- Zawadzki R.J.
Kim DY, Finger J, Zawadzki RJ, et al. Optical imaging of the
chorioretinal vasculature in the living human eye. Proc Natl
Acad Sci U S A 2013;110:14354-9.
Waheed Analysis and interpretation: de Carlo, Bonini Filho, Chin, Adhi, Waheed Data collection: de Carlo, Bonini Filho Waheed Obtained funding: Not applicable Overall responsibility: de Carlo, Bonini Filho Waheed Abbreviations and Acronyms: AMD ¼ age-related macular degeneration
- Conception De Carlo
- Bonini Filho
- Ferrara
- Baumal
- Duker Witkin
Conception and design: de Carlo, Bonini Filho, Ferrara, Baumal, Witkin,
Duker, Waheed
Analysis and interpretation: de Carlo, Bonini Filho, Chin, Adhi, Waheed
Data collection: de Carlo, Bonini Filho, Chin, Baumal, Witkin, Reichel,
Duker, Waheed
Obtained funding: Not applicable
Overall responsibility: de Carlo, Bonini Filho, Chin, Adhi, Ferrara, Baumal,
Witkin, Reichel, Duker, Waheed
Abbreviations and Acronyms:
AMD ¼ age-related macular degeneration; CNV ¼ choroidal neovascularization;
Quantitative optical coherence tomography angiography of choroidal neovascularization in age-related macular degeneration.
- Jia Y.
- Bailey S.T.
- Wilson D.J.
Quantitative optical coherence tomography findings in various subtypes of neovascular age-related macular degeneration.
- Liakopolous S.
- Ongchin S.
- Bansal A.
Spectral-domain optical coherence tomography as an indicator of fluorescein angiography leakage from choroidal neovascularization.
- Giant A.
- Luiselli C.
- Esmaili D.D.