Oct biomarkers of treatment-naive diabetic macular edema in patients with non-proliferative and proliferative diabetic retinopathy

Abstract

Purpose To evaluate and compare the retinal and choroidal spectral-domain optic coherence tomography (SD-OCT) findings of treatment-naïve diabetic macular edema (DME) secondary to non-proliferative and proliferative diabetic retinopathy (NPDR-PDR). Material and methods A hundred and thirty-eight eyes of 138 patients with DME were evaluated. Best-corrected visual acuity was recorded, biomicroscopic anterior and posterior segment examination, SD-OCT imaging, and fundus fluorescein angiography (FFA) were performed. Demographic features, OCT characteristics, FFA, and visual acuity measurements were evaluated and compared between the two groups. Results Sixteen eyes were excluded from the study due to the lack of FFA images. Data of 122 eyes were analyzed for the study. Sixty-five eyes with NPDR (Group 1) and 57 eyes with PDR (Group 2) were enrolled in the study. There was no significant difference in central macular thicknesses (CMT) between the two groups. The eyes with DME + PDR showed a higher rate of the diffuse type of macular edema with more para and peri-foveal extension accompanied by larger cysts than the eyes with DME + NPDR. Disorganization of retinal inner layers, disrupted ellipsoid zone, and the epiretinal membrane were more prominent in the eyes with PDR. Also, there were more prominent macular ischemia on FFA and worse initial visual acuity measurements in the eyes with PDR than those with NPDR. Choroidal thickness (CT) was significantly reduced in the PDR group. Conclusion SD-OCT features of treatment-naïve DME in patients with NPDR and PDR presented some differences. These variations may be related to diabetic retinopathy severity and may provide information about prognosis.