Aims: To estimate the prevalence of diabetic retinopathy (DR) and the possible risk factors associated with DR, in a population of south India. Methods: A cross-sectional sample of subjects aged 30 years and older was selected using a cluster sampling technique from Theni district of Tamilnadu state. Eligible subjects were identified through a door-to-door survey and fasting blood glucose estimation. History of diabetes was elicited, and height, weight and blood pressure were measured for all subjects. Ocular examinations including visual acuity and anterior and posterior segment examinations were performed at preselected sites within clusters. Results: Among the 25 969 persons screened for diabetes mellitus (DM), 2802 (10.8%) (95% CI 9.3 to 12.2%) were found to have DM. DR was detected in 298 (1.2%) of 25 969 subjects. The age–gender-adjusted prevalence of DR is 0.05% (95% CI 0.04 to 0.06%) for rural and 1.03% (95% CI 0.89 to 1.12%) for urban areas. The overall age–gender-cluster adjusted prevalence of DR was 0.74% (95% CI 0.66 to 0.83%). Diabetic retinopathy was present in 12.2% (95% CI 10.4 to 14.1%) of the DM population. Conclusion: Adequate training of ophthalmologists in treating DR and improvement in eye-care infrastructure are needed to tackle this major public health problem in India.

Background: Diabetic retinopathy (DR) is classically defined as a microvasculopathy that primarily affects the small blood vessels of the inner retina as a complication of diabetes mellitus (DM).It is a multifactorial disease with a strong genetic component. The aim of this study is to investigate the association of a set of nine candidate genes with the development of diabetic retinopathy in a South Indian cohort who have type 2 diabetes mellitus (T2DM). Methods: Seven candidate genes (RAGE, PEDF, AKR1B1, EPO, HTRA1, ICAM and HFE) were chosen based on reported association with DR in the literature. Two more, CFH and ARMS2, were chosen based on their roles in biological pathways previously implicated in DR. Fourteen single nucleotide polymorphisms (SNPs) and one dinucleotide repeat polymorphism, previously reported to show association with DR or other related diseases, were genotyped in 345 DR and 356 diabetic patients without retinopathy (DNR). The genes which showed positive association in this screening set were tested further in additional sets of 100 DR and 90 DNR additional patients from the Aravind Eye Hospital. Those which showed association in the secondary screen were subjected to a combined analysis with the 100 DR and 100 DNR subjects previously recruited and genotyped through the Sankara Nethralaya Hospital, India. Genotypes were evaluated using a combination of direct sequencing, TaqMan SNP genotyping, RFLP analysis, and SNaPshot PCR assays. Chi-square and Fisher exact tests were used to analyze the genotype and allele frequencies. Results: Among the nine loci (15 polymorphisms) screened, SNP rs2070600 (G82S) in the RAGE gene, showed significant association with DR (allelic P = 0.016, dominant model P = 0.012), compared to DNR. SNP rs2070600 further showed significant association with DR in the confirmation cohort (P = 0.035, dominant model P = 0.032). Combining the two cohorts gave an allelic P < 0.003 and dominant P = 0.0013). Combined analysis with the Sankara Nethralaya cohort gave an allelic P = 0.0003 and dominant P = 0.00011 with an OR = 0.49 (0.34 - 0.70) for the minor allele. In HTRA1, rs11200638 (G>A), showed marginal significance with DR (P = 0.055) while rs10490924 in LOC387715 gave a P = 0.07. No statistical significance was observed for SNPs in the other 7 genes studied. Conclusions: This study confirms significant association of one polymorphism only (rs2070600 in RAGE) with DR in an Indian population which had T2DM.

The anatomical success rate of macular hole surgery ranges around 93–98%. However, the prognosis of large macular holes is generally poor. The study was conducted to compare the anatomical and visual outcomes of Internal Limiting Membrane (ILM) peeling vis-a-vis inverted ILM flap for the treatment of idiopathic large Full-Thickness Macular Holes (FTMH). This was a prospective randomized control trial. The study included patients with idiopathic FTMH, with a minimum diameter ranging from 600 to 1500 μm. The patients were randomized into Group A (ILM peeling) and Group B (inverted ILM flap). The main outcome measures were anatomical and visual outcome at the end of 6 months. Anatomical success was defined as flattening of macular hole with resolution of the subretinal cuff of fluid and neurosensory retina completely covering the fovea. There were 30 patients in each group. The mean minimum diameters in Group A and B were 759.97 ± 85.01 μm and 803.33 ± 120.65 μm respectively (p = 0.113). The mean base diameter in group A and B was 1304.50 ± 191.59 μm and 1395.17 ± 240.56 μm respectively (p = 0.112). The anatomical success rates achieved in Group A and B were 70.0 and 90.0% respectively (p = 0.125). The mean best-corrected visual acuity (BCVA) after 6 months was logMAR 0.65 ± 0.25 (Snellen equivalent, 20/89) in Group A and logMAR 0.53 ± 0.20 (Snellen equivalent, 20/68) in Group B (p = 0.060). The mean improvement in BCVA was 1.4 lines and 2.1 lines in groups A and B respectively (p = 0.353). BCVA≥20/60 was achieved by 13.3 and 20.0% in group A and B respectively (p = 0.766). The anatomical and functional outcome of Inverted ILM flap technique in large FTMH is statistically similar to that seen in conventional ILM peeling. Clinical Trials Registry – India (Indian Medical Research) CTRI/2017/11/010474 .