Relationship between Recurrence of Macular Edema Due to Branch Retinal Vein Occlusion and Changes in Choroidal Thickness

Abstract

<b><i>Introduction:</i></b> The role of vascular endothelial growth factor in macular edema (ME) due to branch retinal vein occlusion (BRVO) by enhancing vascular permeability has been well studied. ME due to BRVO often recurs; however, there has been no report on the relationship between this recurrence and choroidal thickness (CT), considering the high vascularity of the choroid. This study was designed to investigate this relationship. <b><i>Methods:</i></b> In this retrospective consecutive case series, patients with recurrence of ME within 6 months of receiving intravitreal aflibercept injection treatment for naive ME due to BRVO at Juntendo University Urayasu Hospital were included. Retinal thickness (RT) and CT were measured in the fovea and on the occlusion, non-occlusion, nasal, and temporal sides at baseline, after the first intravitreal aflibercept administration, and before and after recurrence. We also examined the change for each side before and after reinjection. <b><i>Results:</i></b> This study included 11 patients and 11 eyes. The subfoveal CT and RT at baseline were 261.9 ± 93.4 μm and 691.5 ± 254.4 μm, respectively, which significantly decreased to 208.5 ± 70.3 μm and 188.6 ± 33.8 μm, respectively, at 1 month after the first injection (<i>p</i> = 0.001 and <i>p</i> &#x3c; 0.01, respectively). These values also significantly decreased at all the other sites after treatment. There were 14 recurrences within the 6 months following intravitreal aflibercept injection; RT significantly changed at all sites before and after recurrence and reinjection. CT significantly changed at the subfovea and on the occlusion and non-occlusion sides; however, there was no significant change on the nasal and temporal sides. <b><i>Conclusion:</i></b> In patients with BRVO, the CT around the macula after initial treatment was significantly reduced; however, at the time of ME recurrence and reinjection, there were site-dependent differences in the changes observed in the CT. These findings suggest that the pathologies of ME at initial occurrence and at the time of recurrence are different.