Structural and Functional Analyses of Retinal Ischemia in Eyes with Retinal Vein Occlusion: Relationship with Macular Edema or Microaneurysm Formation

Purpose: To study the structural and functional changes of retinal ischemia and investigate their association with macular edema (ME) or microaneurysm (MA) formation in eyes with retinal vein occlusion (RVO). Methods: Sixty eyes of 30 patients (27 eyes with branch [b]RVO, 3 with central RVO, and 30 fellow eyes) were retrospectively reviewed. Optical coherence tomography (OCT), OCT angiography (OCTA), and microperimetry were performed simultaneously to measure retinal thickness and sensitivity. The presence of ME or MA was also assessed using OCT and fluorescein angiography. Results: The mean retinal sensitivity in the nonperfused areas (NPAs) deteriorated, and this was significantly (r = –0.379, p = 0.0391*) and inversely correlated with duration from disease onset. ME and MA were unlikely to be observed around the area where the retinal sensitivity decreased. In the NPAs, the mean retinal thickness of the superficial capillary plexus (SCP) (p < 0.0001), deep capillary plexus (DCP) (p = 0.0323), and outer retina (p = 0.0008) were significantly thinner than those in the fellow eyes, respectively. Multivariate regression analysis revealed that the thicknesses of the DCP (β: 0.3107, p = 0.0007) and outer retina (β: 0.3482, p = 0.0001) were the independent correlative factors of the retinal sensitivity, but that SCP thickness was not. Conclusion: Deep retinal thinning in NPAs was correlated significantly with a decreased retinal sensitivity, which might be a negative predictor of ME and MA in eyes with RVO.