Table 3 - uploaded by Antonio Bergua
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Source publication
Real colour documentation of the optic nerve head (ONH) is one of the most important methods to identify the early progression of glaucomatous optic nerve damage. This study compares the qualitative and semiquantitative evaluation of ONH photographs, using a 3D time-multiplexing system and conventional 2D photography, visualised on a computer monit...
Context in source publication
Similar publications
Purpose:
To describe estimation dynamic distance direct ophthalmoscopy (eDDDO) and compare it with the monocular estimation method of dynamic retinoscopy (eDR) for the assessment of accommodation in children.
Methods:
In this prospective observational cohort study, an ophthalmologist performed eDDDO followed by eDR in children with normal eyes,...
Citations
... However, depth measurement and depth information are not provided. [2][3][4] Current developments in the field of fundus imaging are dominated by scanning laser technologies that do not have the advantage of one-shot technology but have a higher diagnostic potential 5,6 than classical fundus photography. However, with the novel development of 3D light ...
... 11 In particular, the 3D imaging of the optic nerve head and the quantitative analysis of the excavation can be applied in glaucoma diagnostics. 3,4 One strong risk factor for glaucoma is a suspicious optic nerve head appearance with abnormal cupping or an increase in the cup-to-disc ratio. 12,13 With demographic changes in industrialized countries, the incidence of glaucoma is increasing. ...
... (3) What wavelength produces the most depth information? (4) Are structures at deeper layers, such as the choroidea, measurable? (5) What kinds of image artifacts occur? 2 Methods ...
Significance:
Light-field fundus photography has the potential to be a new milestone in ophthalmology. Up-to-date publications show only unsatisfactory image quality, preventing the use of depth measurements. We show that good image quality and, consequently, reliable depth measurements are possible, and we investigate the current challenges of this novel technology.
Aim:
We investigated whether light field (LF) imaging of the retina provides depth information, on which structures the depth is estimated, which illumination wavelength should be used, whether deeper layers are measurable, and what kinds of artifacts occur.
Approach:
The technical setup, a mydriatic fundus camera with an LF imager, and depth estimation were validated by an eye model and in vivo measurements of three healthy subjects and three subjects with suspected glaucoma. Comparisons between subjects and the corresponding optical coherence tomography (OCT) measurements were used for verification of the depth estimation.
Results:
This LF setup allowed for three-dimensional one-shot imaging and depth estimation of the optic disc with green light. In addition, a linear relationship was found between the depth estimates of the OCT and those of the setup developed here. This result is supported by the eye model study. Deeper layers were not measurable.
Conclusions:
If image artifacts can be handled, LF technology has the potential to help diagnose and monitor glaucoma risk at an early stage through a rapid, cost-effective one-shot technology.
... For example, the three-dimensional aspect of CDR is poorly appreciated from two-dimensional images obtained with nonmydriatic cameras. Three-dimensional evaluation of the ONH has been shown significantly more accurate in comparison to traditional two-dimensional pictures [3]. In addition, discrepancies in observer training and experience evaluating the ONH can lead to significant variability in patient referral patterns [4]. ...
... Vessani et al. demonstrated that stereoscopic images of several cameras have better diagnostic performance than subjective assessment of ONH by general ophthalmologists [13]. Other studies have also demonstrated the improved detection of at-risk eyes between stereoscopic imaging and nonstereoscopic imaging with higher CDR in all regions of the ONH and even increased interobserver agreement using stereoscopic imaging compared with monoscopic assessments [3,14,15]. These studies suggest that stereoscopic imaging and depth software analysis could supplement the clinical exam in glaucoma detection during remote screenings and telemedicine efforts. ...
. Software guided optic nerve assessment can assist in process automation and reduce interobserver disagreement. We tested depth analysis software (DAS) in assessing optic nerve cup-to-disc ratio (VCD) from stereoscopic optic nerve images (SONI) of normal eyes.
Methods
. In a prospective study, simultaneous SONI from normal subjects were collected during telemedicine screenings using a Kowa 3Wx nonmydriatic simultaneous stereoscopic retinal camera (Tokyo, Japan). VCD was determined from SONI pairs and proprietary pixel DAS (Kowa Inc., Tokyo, Japan) after disc and cup contour line placement. A nonstereoscopic VCD was determined using the right channel of a stereo pair. Mean, standard deviation,
t
-test, and the intraclass correlation coefficient (ICCC) were calculated.
Results
. 32 patients had mean age of
40
±
14
years. Mean VCD on SONI was
0.36
±
0.09
, with DAS
0.38
±
0.08
, and with nonstereoscopic
0.29
±
0.12
. The difference between stereoscopic and DAS assisted was not significant (
p
=
0.45
). ICCC showed agreement between stereoscopic and software VCD assessment. Mean VCD difference was significant between nonstereoscopic and stereoscopic (
p
<
0.05
) and nonstereoscopic and DAS (
p
<
0.005
) recordings.
Conclusions
. DAS successfully assessed SONI and showed a high degree of correlation to physician-determined stereoscopic VCD.
... Despite being effective for daily activities, monocular vision is of limited use in executing complex tasks that involve greater precision. 2 Stereoscopic imaging techniques are quite old, but previous technologic limitations made production difficult. 3 The computer revolution and development of new photographic and video cameras with digital ca-pabilities, lenses, and flashes with longer ranges allowed improvements in 3D documentation, providing an exponential increase in imaging applications. ...
... However, in our rapidly changing world, 3D images are becoming increasingly common in our daily lives and appear to be moving toward becoming essential, especially in the areas of education and documentation. 2,4 Three-dimensional medical studies are documented in the literature. 1,5 A clearer understanding of anatomic structures is essential in medical education, and the use of 3D images 6 can help greatly in the study of anatomy. ...
The stereoscopic imaging technique is an option for a more realistic understanding of what we normally see in 2 dimensions on paper or on a screen. To produce a 3-dimensional image of an object, it is necessary to register 2 different images of the same object at the same distance and height with the use of cameras that focus on one particular point. A convergence between the left and right images is required for human vision. The distance between the camera and the images necessary to create the stereo pair should be proportional to the normal distance between the pupils. Stereoscopic or polarization techniques are used to create the images, and special glasses are required to view them. In medicine, 3-dimensional images are an extremely effective resource in the study and teaching of anatomy at both the macroscopic and microscopic levels. With advancements in technology and the emergence of new diagnostic imaging techniques and innovative therapeutic modalities, 3-dimensional images can be an excellent educational tool.
The objective was to describe an inexpensive system to visualize stereoscopic photographs of the optic nerve head on computer displays and to transmit such images via the Internet for collaborative research or remote clinical diagnosis in glaucoma. Stereoscopic images of glaucoma patients were digitized and stored in a file format (joint photographic stereoimage [jps]) containing all three-dimensional information for both eyes on an Internet Web site (www.trizax.com). The size of jps files was between 0.4 to 1.4 MB (corresponding to a diagonal stereo image size between 900 and 1400 pixels) suitable for Internet protocols. A conventional personal computer system equipped with wireless stereoscopic LCD shutter glasses and a CRT-monitor with high refresh rate (120 Hz) can be used to obtain flicker-free stereo visualization of true-color images with high resolution. Modern thin-film transistor-LCD displays in combination with inexpensive red-cyan goggles achieve stereoscopic visualization with the same resolution but reduced color quality and contrast. The primary aim of our study was met to transmit stereoscopic images via the Internet. Additionally, we found that with both stereoscopic visualization techniques, cup depth, neuroretinal rim shape, and slope of the inner wall of the optic nerve head, can be qualitatively better perceived and interpreted than with monoscopic images. This study demonstrates high-quality and low-cost Internet transmission of stereoscopic images of the optic nerve head from glaucoma patients. The technique allows exchange of stereoscopic images and can be applied to tele-diagnostic and glaucoma research.
