Analysis of retinal nonperfusion using depth-integrated optical coherence tomography images in eyes with branch retinal vein occlusion.

Abstract

To assess the morphology of areas of complete retinal nonperfusion in eyes with branch retinal vein occlusion (BRVO) by en face images of optical coherence tomography (OCT). Forty-six eyes with BRVO that underwent swept-source OCT (SS-OCT) and fluorescein angiography were enrolled. Depth-integrated images of the neural retina delineated by automated segmentation algorithm were obtained using SS-OCT. The findings in a 6 × 6-mm area on en face SS-OCT scans at the area of retinal nonperfusion were evaluated. Retinal nonperfusion was detected in 25 eyes. Of these, 20 (80%) eyes had multiple concaves of low reflectivity within an area of reticular high reflectivity (honeycomb sign) on depth-integrated images at the area corresponding to retinal nonperfusion. The mean area of retinal nonperfusion and honeycomb sign were 6.72 ± 4.10 mm2 and 4.19 ± 3.37 mm2, respectively. The area of retinal nonperfusion was correlated significantly (r = 0.53, P < 0.001) with the area of the honeycomb sign. The mean retinal thickness in eyes with a honeycomb sign increased significantly (P = 0.017) compared with eyes without a honeycomb sign. Furthermore, after anti-VEGF injection, the mean area of honeycomb sign decreased significantly (P = 0.0013), from 4.23 mm(2) to 0.48 mm(2). Depth-integrated OCT images with automated layer segmentation showed a two-dimensional honeycomb-like structure in retinal nonperfusion with retinal edema. In eyes with BRVO, the thickness of retina did not decrease but increased due to retinal cyst in spite of neural retinal thinning.