Prevalence and incidence of visual impairment in patients with proliferative diabetic retinopathy in India

To provide the real-world outcomes of people with proliferative diabetic retinopathy (PDR) in India and highlight opportunities for improvement of their disease status and to evaluate their visual acuity (VA) status. A multicenter retrospective study in which ten centers in India with established vitreoretinal services for over 10 years were invited to provide long-term data on PDR. This study population were of Indian nationality. Patients with a diagnosis of type 1 or 2 diabetes with a clinical diagnosis of active PDR in any or both eyes, who had long term follow-up for up to 10 years were included. Baseline data collected included age, sex, duration of diabetes, source of referral and best-corrected visual acuity, diabetic retinopathy status in both eyes. Available follow-up data on VA were collected at 6 months post baseline, 5 years and 10 years within a ± 3 months window. Evaluating the presenting VA of people with PDR, short-term outcomes at 6 months and the incidence of visual impairment (VI) at 5 and 10 years are the main outcome of the study. Data was available for 516, 424 and 455 patients at baseline, 5 years and 10 years respectively. Gender and duration of diabetes did not have statistically significant effect on VI outcomes. Eyes receiving treatment early in the disease course (i.e. baseline VA ≥ 6/12) had significantly better VA outcomes at 10 years versus eyes treated at a later stage (i.e. baseline VA < 6/12) (p = <0.0001). On comparing eyes with stable treated PDR and persistent PDR at end of 10 year follow up, a significantly higher percentage of eyes in the stable treated group maintained VA of ≥ 6/12 (55.1% vs. 24.2%) (p = < 0.0001), indicating persistent disease activity due to inadequate treatment results in worse VA outcomes. We found no trend in VI or blindness with increasing levels of age at both 5- and 10-year time points (p > 0.05). The age standardized incidence for VI was 11.10% (95% CI 8.1, 14.2) and for blindness was found to be 7.7% (95% CI 5.2, 10.3). Our results suggest that despite robust recent clinical trial results showing that pan retinal photocoagulation is an excellent treatment for PDR, people with diabetes in India need to be made aware of annual screening and treatment of their eyes to avoid vision impairment and blindness.