Correlation of Vitreous Vascular Endothelial Growth Factor and Uric Acid Concentration Using Optical Coherence Tomography in Diabetic Macular Edema

Purpose. We investigated two factors linked to diabetic macular edema (DME), vitreous and serum levels of vascular endothelial growth factor (VEGF) and uric acid (UA) in patients with DME, and compared the results with changes in optical coherence tomography (OCT) and visual acuity (VA). Methods. A prospective study of 29 eyes, 16 cystoid DME and nonproliferative diabetic retinopathy (DR) and 13 nondiabetic controls. Biochemical analysis of vitreous and serum samples was performed and OCT scans were graded according to central retinal thickness (CRT), cube volume (CV), cube average thickness (CAT), and serous retinal detachment (SRD). Results. In DME group, intravitreal concentrations of VEGF (p < 0.001), UA (p = 0.038), and total protein (p < 0.001) were significantly higher than in control group. In DME subjects, intravitreal UA correlated significantly with intravitreal VEGF (ƍ = 0.559, p = 0.03) but not with total vitreous protein and serum UA. Increased intravitreal VEGF in DME group correlated with increase in CV (ƍ = 0.515/p = 0.041). None of the OCT parameters correlated with the VA. Conclusions. The results suggest that the CV might be assessor of anti-VEGF therapy efficacy. Second, apart from VEGF, the role of UA in the pathogenesis and progression of DR should be considered.