Foveal cystoid spaces are associated with enlarged foveal avascular zone and microaneurysms in diabetic macular edema

Abstract

Objective: To study the association between pathomorphology at the foveal center delineated by spectral domain optical coherence tomography (SD-OCT) and vascular changes around the fovea in fluorescein angiography (FA) in patients with diabetic macular edema (DME).

Design: Retrospective, observational, cross-sectional study.

Participants: Consecutive series of 86 eyes from 72 patients with clinically significant macular edema (CSME) on which SD-OCT and FA were performed on the same day.

Methods: Fluorescein angiography using HRA2 (Heidelberg Engineering, Heidelberg, Germany) and SD-OCT images using Spectralis OCT (Heidelberg Engineering) were obtained for all patients. Microaneurysms (MAs) in the perifoveal capillary network (PCN) and foveal avascular zone (FAZ) in the FA images were quantified. The pathomorphology at the foveal center was evaluated in OCT images. We then investigated the association between pathologic perifoveal capillaries in FA and the neuroglial morphology in OCT.

Main outcome measures: The relationship between pathologic changes in perifoveal capillaries in FA and foveal pathomorphology in OCT.

Results: According to the foveal morphology in OCT images, 44 eyes presented foveal cystoid spaces (cystoid macular edema [CME]), 25 eyes had serous retinal detachment (SRD) at the foveal center, and 17 eyes had foveal thickening without cystoid spaces or retinal detachment (retinal swelling). After 3 eyes with ischemic maculopathy were excluded, the relationship was evaluated. The number of MAs in the PCN was significantly greater in eyes with CME (3.20 ± 1.76) than in eyes with SRD (0.40 ± 1.04; P < 0.01) or retinal swelling (0.47 ± 0.72; P < 0.01). In addition, the FAZ in the eyes with CME (0.553 ± 0.323 mm(2)) was significantly larger than that of the eyes with SRD (0.302 ± 0.245 mm(2); P < 0.01) or retinal swelling (0.268 ± 0.142 mm(2); P < 0.01). These associations were found in eyes with thickened posterior hyaloid membranes.

Conclusions: The eyes with cystoid spaces at the foveal center delineated by OCT had more MAs in the PCN and larger FAZ in FA images.