OUTER RETINAL LAYER THICKNESS AS GOOD VISUAL PREDICTOR IN PATIENTS WITH DIABETIC MACULAR EDEMA.

Abstract

To evaluate the relationship between outer retinal layer (ORL) thickness in diabetic macular edema to visual acuity (VA). Ninety-five eyes were included in this prospective nonrandomized case-control study. They divided into 30 cases of healthy normal subjects and 65 cases of nonproliferative diabetic retinopathy with diabetic macular edema. Complete ophthalmic examination and spectral domain-optical coherence tomography were done for all cases and analyzed to measure central foveal point thickness (CFT), ORL thickness at fovea, and subfoveal choroidal thickness. The ORL thickness was significantly thinner in diabetic macular edema group (85.3 μm) than controls (99.9 μm) (P = 0.002). There was higher significant correlation between ORL thickness and logMAR VA (r = -0.87, P < 0.001) than correlation between CFT and VA (r = 0.18, P = 0.16). The cutoff point of the relationship between ORL thickness and VA was 88 μm with moderate sensitivity (81%) and high specificity (88%), below which vision is affected. Outer retinal layer thickness is significantly related to subfoveal choroidal thickness but not CFT. This study revealed reduction in ORL thickness in diabetic macular edema. There is a higher and stronger correlation between ORL thickness and vision than that between CFT and vision.