Statin use and the risk of progression to vision threatening diabetic retinopathy

PURPOSE: This study aims to assess the effect of statins on progression from non-proliferative diabetic retinopathy (NPDR) to vision-threatening diabetic retinopathy (VTDR), proliferative diabetic retinopathy (PDR) or diabetic macular edema (DME). METHODS: Two cohort studies using a US medical claims database from 2002–2019 including NPDR patients 18 years or older. A risk factor analysis performed a time-updating cox regression model assessing statin usage. A second new-user active comparator design analysis replicating a previously published study. Main outcomes included a new diagnosis of VTDR (composite of either PDR or DME) or DME and PDR individually for the risk factor study and included additional outcomes of new DR, NPDR, vitreous hemorrhage (VH) and tractional retinal detachment (TRD) for the new user study. RESULTS: Risk factor analysis included 66,617 statin users with NPDR at baseline and 83,365 non-statin users. Of these, 27,325(18.2%) progressed to VTDR, 4,086(2.71%) progressed to PDR, and 22,750(15.1%) progressed to DME. After multivariable analysis, no protective effect of statin use was found for progression to VTDR, PDR, or DME (HR=1.01–3, p>0.33 for all comparisons). Replicated new user design analysis also showed no protective effect for statins on risk of development of DR(HR=1.03, 95%CI:0.99–1.07, p=0.13), PDR(HR=0.89, 95%CI:0.79–1.02, p=0.09), DME(HR=0.94, 95%CI:0.86–1.03, p=0.21), VH(HR=1.00, 95%CI:0.86–1.16, p=0.99), and TRD(HR=1.11, 95%CI:0.89–1.38, p=0.36). CONCLUSION: Statin use was found not to be protective for progression of DR regardless of study methodology. These results suggest that the specifics of the population studied rather than differing study methodology are important in assessing the effect of statins on DR progression.