Pattern and distribution of neovascularization in proliferative diabetic retinopathy on fundus fluorescein angiography: A growing paradigm

Corneal parameters in diabetics versus non-diabetics and correlation with various blood sugar parameters

Aim: To compare corneal parameters in diabetics versus age-group-matched non-diabetics; also, to correlate these parameters with the duration of diabetes, glycated haemoglobin (HbA1c) levels, and severity levels of diabetic retinopathy (DR). Materials and methods: A comparative study was conducted at a tertiary eye-care center from January 2020 to December 2020. Two-hundred patients (400 eyes) with type-2 diabetes (100) and age-sex-matched non-diabetics (100) were included. Corneal morphological parameters like central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variance (CoV), hexagonality (6A), and average cell area were recorded by specular microscopy. These parameters were correlated with the duration of diabetes, severity of disease based upon fasting blood glucose levels, HbA1c, and grade of DR. Mean and standard deviation were calculated, and regular distribution of continuous data was tested using independent sample t-test and ANOVA. Results: Mean ECD (2447.32 ± 269.89/mm2), 6A (45.03 ± 6.71%), and IOP (15.47 ± 2.02 mmHg) changed in diabetic cases and were significantly low in diabetics, whereas, mean average cell area (413 ± 50.19 mm2), standard deviation (167.05 ± 77.91), CCT (525.81 ± 36.69) and CoV (39.84 ± 15.59%), were significantly high in diabetics. Mean CCT had insignificant variation. Subgroup analysis within diabetics showed a statistically significant reduction of ECD, cell count, and 6A with increased duration of diabetes, poor glycaemic control, and raised HbA1c. Discussion: The corneal endothelial analysis is vital in daily clinical practice and provides valuable evidence concerning the viability of corneal endothelium in various intraocular surgeries. Uncontrolled DM harms the cornea with 70% of diabetics resulting in complications like keratopathy. The study highlighted that the increased duration of diabetes raised HbA1c, and poor glycemic control negatively affected corneal morphology. Our study showed a definite reduction in ECD and 6A in diabetics compared to non-diabetics. Conclusion: A definite reduction in the corneal endothelial counts, cell density, and hexagonality was found in type-2 diabetics compared to non-diabetics. Abbreviations: DM = Diabetes Mellitus, CCT = central corneal thickness, ECC = endothelial cell counts, ECD = endothelial cell density, CoV = coefficient of variance, 6A = hexagonality, DR = Diabetic retinopathy, SD = Standard of deviation, IOP = Intraocular pressure.

Programmatically Localizing Diabetic Retinopathy Features in 45-Degree Retinal Photographs Using Anatomical Colocation

Background: The aim in this study was to investigate the localization of diabetic retinopathy features at the posterior pole. Methods: This study extracted diabetic retinopathy feature locations from 757 macula-centered 45-degree fundus photographs in the publicly available DDR dataset. Arteriole and venule locations were also extracted from the RITE (n = 35) and IOSTAR (n = 29) datasets. Images were normalized to collocate optic disc and macula positions, and feature positions were collated to generate a frequency distribution matrix. Sørensen-Dice coefficients were calculated to compare the location of different features. Results: Arterioles occurred in two main, distinct arcuate patterns. Venules showed a more diffuse distribution. Microaneurysms were diffusely located around the posterior pole. Hemorrhages and exudates occurred more frequently at the temporal aspect of the macula. Cotton wool spots occurred in a region approximating the radial peripapillary capillaries. Intraretinal microvascular abnormalities and neovascularization were seen throughout the posterior pole, with neovascularization at the disc (n = 65) being more common than neovascularization elsewhere (n = 46). Venous beading occurred primarily between the first and third bifurcations of the venules. Diabetic retinopathy overall was more frequent in the temporal aspect of the macula. The location of cotton wool spots and exudates showed moderate similarity (0.52) when all data were considered, reducing to low similarity (0.18) when areas of low frequency were removed. Conclusions: Diabetic retinopathy occurs throughout the posterior pole but is more frequent in the temporal aspect of the macula. Understanding the location of diabetic retinopathy features may help inform visual search strategies for diabetic retinopathy screening.

Eight years' experience in mobile teleophthalmology for diabetic retinopathy screening

Background

Screening for diabetic retinopathy in the community without compromising the routine work of ophthalmologists at hospitals is the essence of teleophthalmology. This study was aimed at investigating the efficacy of teleophthalmology practice for screening diabetic retinopathy from 2012 to 2020. It was also aimed at comparing the 2-year prevalence of camps organized by a district hospital in South India, as well as the footfall, reporting, follow-up, patient response, and diagnostic efficacy at these camps.

Methods

All patients with diabetes and unexplained vision deterioration attending the mobile camp units underwent non-dilated fundus photography. Patients underwent teleconsultation with the ophthalmologist at the district hospital, and those requiring intervention were called to the district hospital. Trends were studied for the number of patients reporting to the hospital. Patient satisfaction was recorded based on a questionnaire.

Results

A total of 682 camps were held over 8 years, and 30 230 patients were examined. Teleconsultation was done for 12 157 (40.21%) patients. Patients requiring further investigations, intervention for diabetic retinopathy, or further management of other ocular pathologies were urgently referred to the district hospital (n= 3293 [10.89%] of 30 230 examined patients). The severity and presence of clinically significant macular edema increased significantly with an increased duration of diabetes mellitus (P < 0.001). The percentage of teleconsultations showed an increasing trend over the years (P = 0.001). Similarly, considering trends of patients reporting to the hospital, the attrition rate decreased over the years (P < 0.05). A total of 10 974 of 12 157 (90.27%) patients who underwent teleophthalmic consultation were satisfied with the service.

Conclusions

Teleconsultations over the years showed an increasing trend, and the attrition rate decreased over the years. Teleophthalmology is achieving success in providing high-quality service, easy access to care, and in increasing patient satisfaction. Future studies on the role of teleophthalmology for other leading preventable causes of blindness seem possible and necessary.