500-P: Causal Effect of SGLT2 Inhibition on Diabetes-Related Retinopathy (DR) and Macular Edema (DME)

Background: SGLT2 inhibitors have been shown to slow cardiac and renal disease progression. Currently, there is limited literature on the impact of SGLT2 inhibitors on DR and more specifically DME. Objective: Evaluate the effect of SGLT2 inhibitors on central subfoveal thickness (CST) in patients with T2D and on the need and frequency of intravitreal injections (IVI) for DME. Methods: A retrospective matched cohort study with propensity score matching to reduce confounding and determine treatment effect. Covariates: age, sex, type of DM, last A1c, level of retinopathy, insurance, IVI, Visual Acuity (VA). Treatment: SGLT2i use. Primary Outcome: CST on Optical Coherence Tomography (OCT). Secondary Outcomes: IVI use and frequency for DME. By ICD-10 codes 10,026 patients were found to have diabetes and were seen in 2021 at Retina Associates, LLC Kansas City. Retrospectively screened 1,000 consecutive patient medical records from this cohort and included those with T2D and on an SGLT2i. We excluded those with incomplete records, T1D, and those who had a second diagnosis that could cause macular edema. Results: 321 patients had DR; 280 with T2D of which 71 were on an SGLT2i and included for analysis. Baseline cohort characteristics: mean age (SD): 62.2 yr (11.4); 58.9% were male; 76.1% White, 11.1% Black, 6.8% Hispanic/Latino; 13.2% used tobacco; 75.4% had HTN; last recorded A1C 7.6 (1.6); Visual Acuity in ETDRS letters OD: 74.1 (12.9) OS: 73.8 (14.7); CST OD: 279.9 (56.6) OS: 279.6 (54.7). Comparing CST and the need for IVI to those not on an SGLT2i the CST OD/OS was 280.1 (32)/280.3 (36.3) vs 279.9 (62.8)/279.4 (59.7) and 40.8% vs 36.8% required IVI with a risk ratio of 1.13 and a risk difference of 0.03 and p-value of 0.55 95% CI [-0.07, 0.14]. After Propensity Score Matching: ATE risk difference was 0.04 and a p-value of 0.37 and 95% CI [-0.05, 0.14]. Conclusions: No positive or negative effect on mean CST or difference in the average treatment effect for DME was found for those taking an SGLT2 inhibitor.