Corrolation between Foveal Thickness and Visual Acuity in Diabetic Retinopathy

Abstract

Abstract: : Purpose: To investigate the correlation between tomographic features and foveal thickness measured with Optic Coherece Tomography (OCT) with best corrected visual acuity in patients with diabetic retinopathy and Clinically Significant Macular Edema (CSME) Methods: Optic Coherece Tomography (OCT) was performed in 67 eyes of 35 patients, 45% male, mean age 58.8 years (48-72 years), with CSME and diverse degrees of diabetic retinopathy. Tomographic features and macular thickness at the central fovea were recorded. Best corrected visual acuity (BCVA) was assessed and reported in Log(MAR) units. Linear regression analysis was performed. Results: Nonproliferative diabetic retinopathy (DR) was diagnosed in 39% of the eyes and proliferative DR in 61%. The CSME diagnosis was made with the ETDRS guidelines. OCT showed three patterns of diabetic macular edema: cystoid macular edema (21%), retinal swelling (76%) and serous retinal detachment (3%). The linear regression analysis showed a low correlation between macular thickness and BCVA (correlation coefficient: -0.57, r²=0.32) Conclusions: Linear regression analysis showed that changes in macular thickening at the central fovea can explain the 32% of the variations in visual acuity reported on a log(MAR) scale. Other factors that could participate in visual acuity are macular isquemia and CSME duration, among others. These results differ with previous reports.

Keywords: retina • macula/fovea • diabetic retinopathy