Evaluation of Macular Function Tests with Diabetic Retinopathy

Abstract

BACKGROUND Diabetic retinopathy (DR) is reported to be the leading cause of vision loss in adults aged between 20–74 years. Early detection and prompt evaluation is essential to prevent the blindness related to diabetes. Simple and quick out-patient department (OPD) tests are essential for early detection of maculopathy in diabetes, which will enhance the treatment and rehabilitation. The purpose of this study was to evaluate the correlation of photo stress test and Amsler’s grid test with diabetic retinopathy and maculopathy. We also wanted to study the variation in photo stress test and the patterns of visual disturbances using Amsler grid in different stages of diabetic retinopathy. METHODS All patients with type 2 diabetes were included for a study duration of one year. A cross sectional study design was planned. Anterior and posterior segment evaluation was done. Photo stress test was performed with a torch light and the recovery time was recorded. Amsler grid was performed on each patient at 33 cm distance. The results were recorded in terms of micropsia, macropsia, metamorphopsia, and any other ill-defined scotomas. The posterior segment, in terms of vitreous and retina was evaluated with 20 D lens on an indirect ophthalmoscopy and the macular details were evaluated on a 90 D lens with slit lamp biomicroscopy. Early Treatment Diabetic Retinopathy (ETDR) classification was used for classifying the retinopathy and the maculopathy stage in patients. RESULTS There was a correlation between paroxysmal supraventricular tachycardia (PST) and the stage of diabetic retinopathy; between PST and diabetic maculopathy; with increasing severity of diabetic retinopathy and maculopathy associated with higher or prolonged PST values. No correlation was found between Amsler’s grid and DR staging. CONCLUSIONS PST can be used to assess severity of diabetic retinopathy in a pre-clinical and early clinical stage in places where access to the equipment for posterior segment evaluation is unavailable. Amsler’s grid evaluation did not have a role in evaluation of macula in cases of diabetic retinopathy. KEY WORDS Macula, Amsler, Photostress Test, Metamorphopsia