Choroidal Maps in Different Types of Macular Edema in Branch Retinal Vein Occlusion Using Swept-Source Optical Coherence Tomography

Abstract

Purpose To compare choroidal thickness maps of different types of macular edema secondary to branch retinal vein occlusion (BRVO) using swept-source optical coherence tomography (SS OCT). Design Retrospective cross-sectional study. Methods We generated choroidal thickness maps of 55 eyes of 55 patients with BRVO using the macular volumetric raster scan protocol of the SS OCT. The enrolled eyes were classified into 4 types of macular edema according to the captured OCT images: no macular edema (nME, 13 eyes), cystoid macular edema (CME, 15 eyes), serous retinal detachment (SRD, 12 eyes), and mixed type (CME + SRD, 15 eyes). The data from normal fellow eyes served as the control. Statistical analysis was performed to compare choroidal thickness maps according to the type of macular edema. Results The mean choroidal thicknesses in the control, nME, CME, SRD, and mixed-type groups were 205.77 ± 41.65 μm, 211.56 ± 46.34 μm, 214.30 ± 49.21 μm, 249.18 ± 43.51 μm, and 248.05 ± 49.51 μm, respectively. No statistical difference in choroidal thickness was observed among the nME, CME, and control groups, while the SRD and mixed groups showed larger choroidal thickness values than the control group (P ˂.001). No topographic feature in the choroidal thickness was observed to vary according to the location of BRVO. Conclusions The results suggest the choroidal thickness in BRVO varies according to the type of macular edema. Among the macular edema groups, choroidal thickness was significantly increased in eyes with SRD relative to those without SRD, which suggests that increased choroidal thickness may influence the development of SRD in BRVO.