Visual impairment associated with diabetic retinopathy and macular edema: a hospital-based study

Background: Data on visual impairment (VI) in patients with diabetes are necessary in order to guide economic and human resources for reducing its prevalence. Objective: To estimate the prevalence of diabetic retinopathy-related VI in patients with type 2 diabetes in a hospital-based setting. Material and methods: Cross-sectional study carried out from 2014 to 2019 in an ophthalmology outpatient clinic. Any VI was defined as corrected pin-hole visual acuity in the better eye of >= 0.24 logMAR. The presence of diabetic retinopathy (DR), diabetic macular edema (DME) and cataract was evaluated. Results: A total of 840 patients were included; median diabetes duration was 15 years. The prevalence of VI was 30 %. DR was found in 62 % of patients (30 % had sight-threatening DR [STDR]), 17 % had referable DME, and 3 %, cataracts. The odds ratio for moderate or worse VI was 9.02 for STDR (p < 0.001), 5.89 for referable DME (p = 0.001), and 2.51 for cataract (p = 0.006). Conclusion: Thirty percent of participants had some degree of VI. Moderate or worse VI showed a strong association with STDR and referable DME.