Study of visual acuity and contrast sensitivity in diabetic patients with and without non-proliferative diabetic retinopathy

Purpose To analyze high and low contrast visual acuity and contrast sensitivity in diabetic patients without clinically significant macular edema associated or not with non-proliferative diabetic retinopathy. Methods Cross-sectional study of 368 eyes of 368 patients classified into three groups: a) disease-free patients, b) patients with diabetes mellitus (DM) without diabetic retinopathy, c) DM patients with non-proliferative diabetic retinopathy. All patients underwent a complete ophthalmological examination that included high and low contrast visual acuity with 1.25%, 2.5% and 5% contrast chart and Pelli-Robson type contrast sensitivity test. Results We observed no statistically significant differences regarding age, intraocular pressure, duration of diabetes or high contrast visual acuity. The eyes of patients with non-proliferative diabetic retinopathy had worse contrast sensitivity (p = 0.03, in both cases) and low contrast visual acuity at 1.5% (p = 0.03 and p = 0.01), 2.5% (p = 0.01, in both cases) and 5% (p = 0.02 and p = 0.04) than patients free of disease or without diabetic retinopathy. Conclusions Analysis of contrast sensitivity and low contrast visual acuity could be considered as markers of visual function impairment in the eyes of patients with non-proliferative diabetic retinopathy.