Characteristics of macular edema associated with retinal vein occlusion showing poor anatomic response to three loading anti-vascular endothelial growth factor injections: an optical coherence tomography analysis

Purpose To analyze the clinical features of refractory cystoid macular edema related to retinal vein occlusion associated with the response to three consecutive loading doses of anti–vascular endothelial growth factor. Methods A retrospective chart review was performed on retinal vein occlusion patients treated by three anti–vascular endothelial growth factor injections. They were divided into a group according to resolution of macular edema in optical coherence tomography (Group 1) and with persistent macular edema (Group 2). We analyzed qualitative and quantitative morphologic features of optical coherence tomography. Results We enrolled a total of 120 eyes from 120 patients (Group 1: n = 54, Group 2: n = 66). The baseline choroidal thickness differed significantly between groups 1 and 2 (290.70 ± 19.58 μm and 311.06 ± 17.87 μm P < 0.001). The presence of Hyperreflective foci (16.70% vs. 36.40% P < 0.001), Disorganization of the retinal inner layers (14.80% vs. 87.90%) and external limiting membrane disruption (16.60% vs. 39.3% P < 0.001) differed significantly. Logistic regression analysis showed that the initial central macular thickness (B = 0.012; P = 0.006), baseline choroidal thickness (B = 0.232; P = 0.016) and presence of hyperreflective foci (B = 1.050; P = 0.019), disorganization of the retinal inner layers (B = 1.132; P = 0.001) and external limiting membrane disruption (B = 1.575; P = 0.012) significantly affected the anti–vascular endothelial growth factor treatment response. Conclusion A thicker sub-fovea choroid and the presence of hyperreflective foci, disruption of the external limiting membrane and disorganization of the retinal inner layers associated with a poorer response to three loading anti–vascular endothelial growth factor injections in macular edema associated retinal vein occlusion.