Evaluation of Retinal and Choroidal Thicknesses in Patients with Diabetes Mellitus Without Diabetic Retinopathy: A Comparative Study

Abstract

Background: One of the most important complications of diabetes mellitus (DM) is vision loss due to diabetic retinopathy (DR). Optical coherence tomography (OCT) provides visualization of early structural abnormalities of the retina and choroid. Aim: To compare retinal thickness (RT) and choroidal thickness (CT) between patients with DM without DR and healthy controls. Patients and Methods: Diabetic patients without DR were divided into two groups according to serum glycosylated hemoglobin (HbA1c) levels. Group 1: HbA1c <= 7.5 (n = 25) and group 2: HbA1c >7.5 (n = 23). The 3(rd) group was the healthy control group (n = 25). CT and RT measured by OCT were compared between the three groups. Results: CT in the subfoveal, temporal, and nasal quadrants was significantly higher in the healthy control group than in groups 1 and 2. Subfoveal and temporal quadrant CT in group 2 were significantly thinner than those in group 1. The average RT (ART) was thinner in group 1 than in the other groups, but there was no difference between the control group and group 2. Conclusions: This study showed that CT and ART decreased in diabetic patients without DR.