Assessment of Color Vision in Diabetic Patients

Abstract

Aim: To assess the changes in color vision in diabetic patients in different stages of diabetic retinopathy compared to healthy individuals.

MATERIALS AND METHODS: This cross-sectional comparative study included sixty-eight eyes of 40 diabetic patients, divided into four subgroups (10 patients / group) at different stages of diabetic retinopathy (Eighteen of them had maculopathy) as well as 20 eyes of 10 healthy individuals as controls. Diabetic retinopathy and maculopathy were assessed clinically by direct and indirect fundus examination along with fluorescein fundus angiography, optical coherence tomography. Color vision was assessed quantitatively by Ishihara pseudo iso-chromatic plates test and qualitatively by Farnsworth D-15 test.

Results: Only two control eyes (10%) failed the Ishihara pseudo iso-chromatic plates test, compared to 19 diabetic eyes (27.9%), 14 eyes (20.58%) were suspects. Also just two control eyes (10%) failed the Farnsworth d-15 test while 34 (50%) diabetic eyes failed the test showing; with Tritanopia was the most encountered color vision defect. We find that color vision defects also increases with increasing disease duration, severity of diabetic retinopathy, increased macular thickness and presence of maculopathy, while type of diabetes shows no significant effect.

Conclusion: Diabetes mellitus has a clear negative effect upon the color vision in both qualitative and quantitative manner leading to loss of color vision perception with a varying degree in relation to the type of diabetes, degree of retinopathy, the duration of illness, presence of maculopathy and the increased macular thickness when compared to normal healthy individuals.