Contrast sensitivity is associated with outer‐retina thickness in early‐stage diabetic retinopathy

Purpose To determine the relationship between contrast sensitivity (CS) and outer‐retina thickness (ORT) in diabetics who have minimal or no diabetic retinopathy (DR). Methods Twenty non‐diabetic control subjects and 40 type‐2 diabetic subjects participated (20 had no clinically apparent DR [NDR] and 20 had mild non‐proliferative DR [NPDR]). No subject had a history of treatment for macular oedema. Letter CS, microperimetry (MP) sensitivity and visual acuity (VA) were measured. Letter CS and MP measurements were performed over the central 6° of the visual field. Spectral domain optical coherence tomography (SD‐OCT) images were obtained at corresponding locations, outer‐retina thickness was quantified, and structure–function relationships were evaluated. Results Analysis of variance indicated significant letter CS differences among the groups (p