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Spheroidal degeneration with yellow spherules and irregular surface before phototherapeutic keratectomy
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Phototherapeutic keratectomy (PTK) is done regularly for anterior corneal diseases such as corneal dystrophies, corneal degenerations, scars, and band-shaped keratopathy. The various indications include both therapeutic and visual. The aim of this article is to discuss the therapeutic indications for PTK, the specific technique pertaining to a spec...
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Background:
Four eyes of two patients were injured simultaneously by industrial alkali while working. One eye of both patients healed without later consequences.
Patients and methods:
Two eyes were treated with phototherapeutic keratectomy (PTK) because of recurrent corneal erosion syndrome caused by alkali burn.
Results:
In both cases reepith...
Purpose: To evaluate the surgically induced astigmatism (SIA) 1 year after excimer laser photorefractive astigmatic keratectomy (PARK) and photorefractive keratectomy (PRK).Setting: Royal Victorian Ear and Eye Hospital, Melbourne, Australia.Methods: This study comprised 333 PARK patients and 155 PRK patients treated with a VISX 20/20 excimer laser...
Citations
... The procedure can be repeated if necessary, provided there is adequate corneal thickness [9]. Complications of PTK include infection, delayed healing of the epithelium, reactivation of herpes simplex virus, and recurrence of bullous keratopathy [8,10]. ...
BACKGROUND: We report a case of late-onset chronic fistula in a decompensated cornea after multiple ocular surgeries and a recent phototherapeutic keratectomy (PTK).
CASE REPORT: A 73-year-old woman presented to our service with a past ocular history of bilateral chronic angle closure glaucoma and pseudophakic bullous keratopathy in the left eye. Given a history of long-term uncontrolled glaucoma with advanced disc cupping and poor visual potential, the patient underwent multiple palliative procedures, including, most recently, a PTK. Few years later she presented with a spontaneous late onset of slowly appearing corneal leak on fluorescein staining upon routine clinical examination. Corrected distance visual acuity was hand motion and intraocular pressure (IOP) was 40 mmHg in the affected eye. Serial anterior segment optical coherence tomography (AS-OCT) sections were obtained, which aided in understanding the current presentation and revealed distinctive multilayer corneal changes during the healing process. The patient was successfully managed with cyanoacrylate corneal gluing and ocular hypotensive medications, which halted the corneal leak.
CONCLUSIONS: We report a case of a rare finding of corneal fistula in an eye with multiple previous ocular surgeries, and provide an explanation of the possible etiopathogenesis. We also highlight the pivotal role of AS-OCT for evaluating such cases and stress the importance of early detection of similar subtle leaks in the setting of a formed anterior chamber, which can often be missed, carrying a risk of infection.
... Obrart et al. [29] found that only the slightest subepithelial haze appeared in 5 eyes during the first 3 months, which improved rapidly, and there was no evidence of persistent corneal opacity disturbances associated with photoablative 6 months after surgery. Cases with delayed epithelial healing and deeper ablation had an increased risk of postoperative haze formation [33]. Unlike PRK [27,28], haze was not visible or was only occasionally observed after PTK, which may be attributed to the limited ablation depths used in the treatment of RCES patients. ...
Background:
Phototherapeutic Keratectomy (PTK) has been increasingly used to treat severe recurrent corneal erosion syndrome (RCES) patients who do not respond to other treatments. However, the efficacy and complication of each study are currently uncertain due to varying rates.
Objectives:
The objective of this study was to investigate the safety and efficacy of the Phototherapeutic Keratectomy for recurrent corneal erosions.
Methods:
This article performed a systematic literature research in Cochrane, Embase, PubMed, Scopus, and the Web of Science for the literature on PTK treatment of RCES until December 20, 2022. The extracted data include recurrence rate and the adverse event rate were used for meta-analysis.
Results:
The recurrence rate was 18% (95% CI, 13%-24%) (129/700 eyes). Subgroup analysis showed that the RCE recurrence was 17% (95% CI, 9%-24%) after trauma and 22% (95% CI, 11%-32%) in the corneal dystrophy group. Treatment-related adverse events included subepithelial haze, hyperopic shift, and decrease of the best spectacle corrected visual acuity (BSCVA). In this study, the incidence of these events were 13% (95% CI, 6%-21%), 20% (95% CI, 11%-28%), and 11% (95% CI, 5%-16%), respectively.
Conclusions:
PTK represented a valuable treatment option for patients with recurrent corneal erosions, especially those with traumatic injuries, which had minimal side effects.
... Phototherapeutic keratectomy (PTK) and penetrating keratoplasty (PKP) are the most recommended visual rehabilitation methods for GCD cases with significant corneal opacities [15][16][17][18]. In addition to the histopathological changes in GCD, these surgical interventions may affect corneal biomechanical strength [19,20] and increase the rate of ectasia reoccurrence after surgery [21,22], so the assessment of corneal biomechanics in this group of disorders seems reasonable. ...
Background:
The aim of this study was to assess stress-strain index (SSI) and corneal biomechanical parameters in eyes with granular corneal dystrophy (GCD).
Methods:
This case-control study included 12 eyes of 12 patients with GCD (mean age 45.2 ± 18.7 years) and 20 eyes of 20 healthy individuals (mean age 54.4 ± 3.8 years). In addition to SSI, dynamic corneal response (DCR) parameters were assessed at the first and second applanation, including length (AL1, AL2), velocity (AV1, AV2), time (AT1, AT2), and deformation amplitude (DA A1, DA A2), and at the highest concavity (HC) phase, including DA, peak distance (PD), radius (HCR), and DA ratio (DAR 1 and 2 mm), by Corvis ST. Central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were considered covariates in comparing DCR parameters between the two groups.
Results:
SSI was statistically significantly lower in eyes with GCD than in normal eyes (p = 0.04). The corneal velocity towards the first applanation was 0.02 m/s faster in the GCD eyes AV1 (0.15 ± 0.02 vs. 0.13 ± 0.02 m/s, p < 0.001) and IR (7.48 ± 1.01 vs. 6.80 ± 1.22 mm, p = 0.003) parameters were significantly higher in the GDC group, while AT1 (7.33 ± 0.66 vs. 7.47 ± 0.36 ms, p = 0.002) and HCR (7.42 ± 0.76 vs. 8.20 ± 1.08 mm, p = 0.014) were significantly lower in the normal group.
Conclusions:
GCD led to a change in biomechanical properties of the cornea. SSI refers to fewer stiff corneas in GDC than normal.
... Superficial anterior stromal diseases can be treated with minimally invasive surgical procedures, including superficial keratectomy, lamellar keratoplasty, and excimer lasers, that is, phototherapeutic keratectomy (PTK) (2) . At this point, PTK represents a bridge that links medical and surgical treatments (3) . ...
... PTK can be used for many refractive and/or therapeutic indications (3) . In this study, we aimed to investigate the efficacy of PTK as the treatment for anterior corneal pathologies and assess the refractive and therapeutic effects of PTK. ...
... The delayed healing of epithelial defects, which are generally expected to heal within 1 week, increases the risk of haze and infection (3) . An infection should be expected in such diseased corneas, especially when presenting with an epithelial defect and delayed healing. ...
Purpose: To examine the efficacy of phototherapeutic keratectomy as a treatment for variable pathologies with anterior corneal opacities and evaluate the distribution of phototherapeutic keratectomy indications over the past 10 years.
Methods: The records of 334 eyes from 276 patients who underwent phototherapeutic keratectomy between March 2010 and 2020 were retrospectively reviewed. Etiologies of the patients who underwent phototherapeutic keratectomy were noted, and their changes were examined. Refractive and visual acuity results before and after the operation were recorded and analyzed according to etiology.
Results: The mean age of the patients was 40.7 ± 16.2 years (range: 19-84). The mean follow-up was 25.5 ± 19.1 months (range: 3-96). Phototherapeutic keratectomy was most frequently applied for corneal stromal dystrophies (44%, 151 eyes from 111 patients), and granular dystrophy was the most common phototherapeutic keratectomy indication among corneal dystrophies. Unlike other indications, there has been an increase in the application of phototherapeutic keratectomy for persistent subepithelial opacities due to adenoviral conjunctivitis in the past 10 years. There was a significant increase in visual acuity in all groups except for the recurrent epithelial defect group (p<0.05). The greatest improvement in visual acuity was detected for stromal dystrophies in the granular dystrophy subgroup.
Conclusion: Despite changing indication trends, phototherapeutic keratectomy remains an effective and reliable treatment for anterior corneal lesions.
... Before considering a photoablation procedure such as PTK, it is important to have an objective measurement of corneal thickness as well as the localization of the foreign bodies on the corneal/ conjunctival surface (3). In the context of a patient with multiple chronic foreign bodies the indication of PTK is based on the clinical judgment of the specialist, being the best candidates those with opacities in 10-20% of the anterior cornea and/ or conjunctiva, without significant irregularities and thinning (10). The possible adverse effects of PTK like any other method of photoablation such as refraction error and secondary infections must be considered. ...
... The possible adverse effects of PTK like any other method of photoablation such as refraction error and secondary infections must be considered. Corneal topography, ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT) are very useful in these cases to plan and manage the postoperative result (10). ...
We examined a male patient with multiple corneal and conjunctival foreign bodies. The composition of the material seemed not to be toxic due to the non-inflammatory, calm appearance of the eye and the asymptomatic course. Therefore, the removal of the foreign bodies was not necessary. Currently, the patient remains asymptomatic.
... Numerous causes have been implicated in the occurrence of DLK, including the presence of particles and debris during surgery 2 , glove powder 3 , red blood cells 4 , tissue particles 1, endotoxins, secretions, and secretions 5 , incidence of corneal epithelial defects and infiltration of betadine solution 6 . Treatment with corticosteroids before and after surgery reduces the severity of DLK 6,7 , but treatment with fabric membrane stabilizers and nonsteroidal anti-inflammatory drugs have less effect on the DLK process after surgery 8 . Increased intraocular pressure (IOP) following surgery can create a clinical picture similar to DLK (false DLK) 9 . ...
Background: And aim: The prevalence of DLK has been reported differently in different centers based onits severity. Hence, the aim of present study was evaluate the prevalence, natural course, and final visualacuity in patients with stages III or IV of diffuse lamellar keratitis following laser in situ keratomileusis.Methods: In the present descriptive study, 3941 eyes files from 2125 patients underwent LASIK surgery;were examined. All patients had a complete ophthalmologic examination before LASIK and had suitableconditions for LASIK.Result: Among the studied cases, 39 eyes (0.98%), out of 16 patients (0.75). The mean time intervalbetween LASIK and DLK diagnosis was 3± 2.4 days. A history of allergy was negative in all patients. Themean post-operative spherical refractive error in all eyes was in the range of 1 diopters and the averagecylindrical refractive error in 33 eyes was -0.66±1.2 diopters. The mean of final spherical refraction in34 eyes was 0.5±1.2 diopter and the mean of final cylindrical refraction in 35 eyes was -0.75±1.3 diopter.Severe turbidity at the flap surface in the first week decreased over time in all patients with stage III and IVDLK. So that only in four eyes (10.25%)Conclusion: The prevalence of stages III and IV in DLK is negligible compared to the large number ofLASIK procedures and all patients respond well to topical and systemic corticosteroid therapy.
... Phototherapeutic keratectomy (PTK) and transepithelial photorefractive keratectomy (t-PRK) are safe and efficient procedures that use a 193-nm argonfluoride laser to ablate corneal tissues [12][13][14]. Although PTK can be applied to a wide range of corneal disorders, t-PRK may be preferred for patients who have a refractive error [15]. ...
PurposeTo evaluate long-term visual and refractive outcomes of corneal wavefront-guided transepithelial photorefractive keratectomy (t-PRK) with mitomycin C for the treatment of corneal opacities secondary to adenoviral epidemic keratoconjunctivitis.Methods
Records of patients who underwent corneal wavefront-guided t-PRK with excimer laser from January 2012 to December 2018 were retrospectively reviewed. Preoperative and postoperative uncorrected visual acuity, best-spectacle corrected visual acuity, slit-lamp biomicroscopic examination findings, manifest refraction, and corneal aberrations and fundus examination findings were evaluated.ResultsTwenty-two eyes of 22 patients comprising 12 male (55%) and 10 female (45%) were treated. The mean age was 34.5 ± 10.8 years (range 19–55). The mean follow-up time was 34.4 ± 17.50 months (range 13–61 months). There was a statistically significant improvement in UCVA and BSCVA (p < 0.001 and p = 0.02), and there was a significant decrease in total higher-order aberrations, spherical, coma and trefoil aberration at postoperative first year (p < 0.001 in each). In two eyes of two patients, minimal haze formation was observed after the procedure, and both eyes were treated with topical steroid. No recurrence was observed in subepithelial infiltrates in any patient during long-term follow-up.Conclusion
In long-term clinical follow-up, corneal wavefront-guided t-PRK treatment is an effective and reliable treatment method for rehabilitation of visual impairment due to corneal scars following adenoviral infections, in properly selected patients.
... In patients with multiple failed corneal transplantations or grafts, the Boston Keratoprosthesis (KPro) implantation may help manage corneal LSCDs [52]. Phototherapeutic keratectomy (PTK) may be beneficial by applying a laser to the basement membrane and Bowman's layer to facilitate stronger adhesion mechanisms [4,53,54]. PTK may be able to treat both refractive errors and epithelial defects [4]. ...
Persistent corneal epithelial defects (PEDs or PCEDs) result from the failure of rapid re-epithelialization and closure within 10-14 days after a corneal injury, even with standard supportive treatment. Disruptions in the protective epithelial and stromal layers of the cornea can render the eye susceptible to infection, stromal ulceration, perforation, scarring, and significant vision loss. Although several therapies exist and an increasing number of novel approaches are emerging, treatment of PEDs can still be quite challenging. It is important to treat the underlying causative condition, which may include an infection, limbal stem cell deficiency, or diabetes, in order to facilitate wound healing. Standard treatments, such as bandage contact lenses (BCLs) and artificial tears (ATs), aim to provide barrier protection to the epithelial layer. Recently-developed medical treatments can target the re-epithelialization process by facilitating access to growth factors and anti-inflammatory agents, and novel surgical techniques can provide re-innervation to the cornea. PEDs should be treated within 7-10 days to avoid secondary complications. These interventions, along with a step-wise approach to management, can be useful in patients with PEDs that are refractory to standard medical treatment. In this review, we discuss the epidemiology, etiology, diagnosis, current and novel management, and prognosis of persistent epithelial defects.
... However, postoperative redevelopment of opacities in corneas has been frequently reported, especially among patients with some types of CD, such as Reis-Bücklers corneal dystrophy (RBCD) [2][3][4][5][6][7][8][9]. Compared with penetrating keratoplasty (PKP) or lamellar keratoplasty, PTK is less invasive and does not require a corneal graft; thus, it is more efficient for the treatment of CD patients who experience a high rate of recurrence [10]. Previous research demonstrated that, in CD patients treated with PTK, best-corrected visual acuity considerably improved postoperatively [11][12][13][14][15]. Additionally, PTK is effective for treating CD opacities that redevelop postoperatively [16][17][18][19][20][21]. ...
... According to previous studies [10,23], PTK might be accompanied by the risk of delayed corneal epithelial healing or haze. This led us to consider that multiple PTK treatments may pose a higher risk for the abovementioned effects. ...
Background:
To investigate the efficacy and safety of repeated phototherapeutic keratectomies (PTKs) during long-term treatment for corneal dystrophy (CD) in a Chinese pedigree carrying the R124L mutation in TGFBI.
Methods:
This was a retrospective review of 20-year medical and genetic records involving five CD patients (10 eyes) from one pedigree. During this period, PTK was conducted for an eye when best-corrected distance visual acuity (BCDVA) reached > 1.0 (LogMAR), due to either primary or recurrent opacities in the cornea. All PTKs were performed by 193-nm excimer laser with or without creation of epithelial flaps. For each eye, routine measurements were conducted for the number of PTKs during follow-up, mean time to recurrence, and BCDVA pre- and post- every PTK (measurements within 3 months from each PTK). Corneal thicknesses measured after the last PTK and at the last visit were analyzed, and subjective satisfaction was assessed.
Results:
Gene testing revealed an R124L mutation in TGFBI. During 19.60 ± 1.78 years of follow-up, PTKs were conducted twice for three eyes, three times for six eyes, and four times for one eye. After each PTK, effective visual acuity was maintained for 3.60 ± 1.12 years before significant recurrence. BCDVA improved significantly postoperatively than preoperatively for the first PTK for each eye (p < 0.001), as well as the second (p < 0.001) and third one (p < 0.001). After the last PTK and at the final visit, the thinnest corneal thickness was 371.50 ± 56.47 μm and 358.40 ± 101.11 μm, respectively. The average subjective satisfaction score was 8.60 ± 0.89.
Conclusions:
Multiple repeated PTKs were effective and safe in a long-term study of CD patients with an R124L mutation in TGFBI.
... General anesthesia may be required in patients requiring additional surgical procedures and in pediatric patients. 154,155 A written and informed consent should be obtained from the patients, explaining the possible risks and complications of the surgical procedure. Asepsis is achieved using 5% povidone-iodine solution, and a wire speculum is applied for adequate exposure. ...
... Various visual and auditory signals have been described, which help in guiding the extent and depth of ablation during surgery. 112,155 These include snapping sound heard during tissue ablation, soft sound produced during ablation of masking fluid, and bubbling sound, suggestive of excess amount of masking fluid. 155 Visual indicators include blue fluorescence observed in a dark room with epithelial ablation. ...
... 112,155 These include snapping sound heard during tissue ablation, soft sound produced during ablation of masking fluid, and bubbling sound, suggestive of excess amount of masking fluid. 155 Visual indicators include blue fluorescence observed in a dark room with epithelial ablation. ...
Phototherapeutic keratectomy is an excimer laser-based surgical procedure widely performed by corneal surgeons for treating anterior corneal stromal pathologies. Phototherapeutic keratectomy helps by ablating the corneal stroma, thereby improving corneal clarity and smoothening the surface. Transient discomfort and induced hyperopia from corneal flattening are the immediate postoperative concerns. The long-term course is often marked by the recurrence of original corneal pathology and corneal haze formation. Phototherapeutic keratectomy, however, allows for repeat stromal ablation for managing recurrences, as the corneal thickness permits, without affecting the outcome of future keratoplasty. Adjunctive methods such as topical mitomycin-C may be additionally used to reduce recurrence rates. Also, various masking agents such as carboxymethyl cellulose, sodium hyaluronate, and dextran are used in eyes with irregular corneal surface to allow for uniform stromal ablation. Overall, phototherapeutic keratectomy has provided corneal surgeons an additional surgical tool, particularly those residing in developing nations where the availability of donor corneal tissue is an important limiting factor.
