Severe Macular Ischemia Is Associated with a Poor Visual Prognosis and Serious Complications in Eyes with Central Retinal Vein Occlusion

Purpose: This study aims to investigate the factors influencing post-treatment visual acuity (VA) in patients with central retinal vein occlusion (CRVO) with macular edema (ME). Methods: The subjects of this study were patients who visited our clinic from May 2013 to July 2019 and who could be followed up with for at least 12 months. Cases with hemi CRVO were excluded from this study. Factors considered in the evaluation of visual prognosis at the 12 months included initial best-corrected VA, central subfoveal thickness, CRVO subtype (nonischemic, ischemic, or converted from nonischemic to ischemic), time taken for the first treatment, number of anti-vascular endothelial growth factor agent injections, structural changes in the inner and outer retinal layers, and the presence of macular ischemia in a multiple regression analysis. Results: There were 41 patients with 41 eyes, 27 males and 14 females. The mean age of the patients was 70.5 ± 12.2 (mean ± standard deviation) years. The mean VA was 0.544 ± 0.576, 0.456 ± 0.568, and 0.586 ± 0.665 at the initial visit, 12 months later, and time of last observation, respectively. There were no significant differences in VAs observed between the baseline, month 12, and final visit. Multiple regression analysis revealed that the external limiting membrane score at month 12 (p = 0.030), the VA at initial visit (p < 0.001), and the presence of severe macular ischemia (p < 0.001) were the key factors associated with VA at month 12. Moreover, severe macular ischemia was identified as the only factor affecting decimal VA less than 20/200 at the last observation (p = 0.0092). Conclusions: Severe macular ischemia is strongly linked to a poor visual prognosis in patients with ME associated with CRVO.