An innovative and simple method, clinically comparable to high-definition optical coherence tomography in quantifying posterior segment lesions in the retina.

Purpose: To introduce a simple and inexpensive method using a fundus contact lens and a reticle, to measure retinal lesions comparing it with values obtained with high-definition optical coherence tomography (HD-OCT). This study considers optic disc as the object for comparison. Methods: : Patients underwent routine ophthalmologic examination and their horizontal optic disc diameter was measured, both with the reticle and OCT. For measurement with reticle a simple equation was deduced, x = 0.7y, where x corresponds to the actual image size and y to the reticle scale reading in millimeters. Results: : An aggregate of 127 eyes of 75 patients were dilated and examined. The calculated mean diameter according to OCT was 1.639 mm (standard deviation = 0.179) and that assenting to reticle was 1.713 mm (standard deviation = 0.175), with a difference in mean being 0.089 mm. Conclusion: Values obtained by this new method was found to be comparable with the OCT values for retinal measurements, useful for ophthalmologists who cannot afford expensive and sophisticated machines.

Disc Configuration as a Risk and Prognostic Factor in NAION: The Impact of Cup to Disc Ratio, Disc Diameter, and Crowding Index.

Purpose: The presence of the so called disc at risk (a small disc with no cupping) has been considered the main risk factor for the development of non-arteritic anterior ischemic optic neuropathy (NAION). However its role as a prognostic factor has not been studied. Our aim was to determine the weight of disc configuration as a risk and a prognostic factor for NAION. Methods: Case control study. Forty eyes of 40 patients who were diagnosed with NAION between 2008 and 2017, and 120 controls (3 controls for each patient) were included in the study. Disc diameter (DD), cup to disc ratio (CDR), and peripapillar retinal nerve fiber layer thickness (RNFLT) of the non-affected eye were measured using optic coherence tomography (3D OCT 2000, Topcon). Crowding index (CI) was defined as the quotient of average RNFLT and disc area. Mean deviation (MD) at the time of diagnosis and at least three months later was determined using a Humphrey Visual Field Analyzer (SITA standard 24-2 strategy). Visual acuity (VA) was measured using Snellen charts and transformed into LogMAR values. Results: Only CDR was found to be a risk factor for NAION. No correlationship was found between CI and visual loss. Conclusions: DD and CI did not show value as either prognostic or risk factors. Glial tissue may be a part of the content of the optic disc as important as axons. Our results are in line with the latest studies about NAION pathophysiology. Contrary to classic thinking, these papers have not found smaller disc diameters, but smaller values of lamina cribosa depth in NAION patients.

Optic disc area in Malaysian population / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM: To evaluate the optic disc parameters in the three main ethnic groups of Malaysia (Malay, Chinese and Indian). Possible relationships between optic disc parameters and gender, intraocular pressure and axial length of eye were also studied. · METHODS: The study included 244 eyes of 122 subjects (61 cases with open angle glaucoma and 61 non- glaucomatous individuals) with clear ocular media. Magnification corrected measurements of optic disc diameters and area were done using Zeiss FF450 Plus fundus camera. Differences between the three ethnic groups were tested by using ANOVA. The association between factors such as gender, intraocular pressure and axial length of the eye, and the optic disc size was tested through Pearson's bivariate correlation analysis. · RESULTS: The overall mean vertical optic disc diameter as (1.96 ± 0.20) mm, horizontal optic disc diameter was (1.84±0.20)mm and optic disc area was (2.84±0.56)mm2. Indians had larger optic disc area compared to Malay and Chinese. However, the difference was not statistically significant. · CONCLUSION: Optic disc size is larger in Malaysian population than Caucasians, Among the three ethnic groups, Indians have the largest optic disc size without any statistical difference.