Need for Vitreous Surgeries in Proliferative Diabetic Retinopathy in 10-Year Follow-Up: India Retinal Disease Study Group Report No. 2.

INTRODUCTION: To report the 10-year rate of vitrectomies and the associated factors in people with proliferative diabetic retinopathy (PDR) from a multicentric cohort of people with diabetes mellitus. METHODS: Ten centres in India with established vitreoretinal (VR) services for over 10 years were invited to provide long-term data on PDR. People with Type 1 or 2 diabetes with a clinical diagnosis of active PDR in 1 or both eyes were included. Baseline data collected included age, sex, duration of diabetes, source of referral and best-corrected visual acuity, and diabetic retinopathy status in both eyes. Available follow-up data included the numbers of panretinal photocoagulation (PRP) sessions, cataract surgery, treatment of diabetic macular oedema, use of anti-vascular endothelial growth factor (VEGF) therapy, vitrectomy with or without retinal surgeries over 10 years. RESULTS: Over 10 years, 89% needed supplemental PRP after initial complete PRP. One-third required retinal surgery, 16% needed intravitreal injection. Men (74.5%) had significant higher risk for vitreous (VR) surgery. Of the group with low-risk PDR, 56.8% did not require VR surgery, p < 0.001. Of the patients who underwent cataract surgery and had intravitreal anti-VEGF injections, 78.5 and 28.2% needed subsequent vitreous (VR) surgery, p = 0.006 and <0.0001, respectively. Independent predictors of need for vitreoretinal surgery included those who underwent cataract surgery and those with poor baseline visual acuity (logMAR). Eyes at lower risk for VR surgery included the eyes previously treated with PRP and low-risk PDR at baseline. CONCLUSION: Despite initial "complete" PRP, one-third of our study cohort needed vitrectomies over 10 years, highlighting that these patients require regular follow-up for a long period of time.

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.