Microvascular Changes in the Cystic Lesion of Branch Retinal Vein Occlusion Imaged by Swept-Source Optical Coherence Tomography Angiography

Abstract

<b><i>Introduction:</i></b> This study aimed to describe the quantitative features of the microvasculature in the cystic lesions of branch retinal vein occlusion (BRVO). <b><i>Methods:</i></b> A total of 43 eyes with BRVO, treated with anti-vascular endothelial growth factor therapy, were analyzed. Using wide-field swept-source optical coherence tomography angiography (OCTA), en face OCT images were obtained by depth-integrated reflectivity of the retina, and vascular density (VD), vascular length (VL), vascular lacunarity, and fractal dimension (FD) were evaluated in a 12 × 12-mm area of retinal nonperfusion. <b><i>Results:</i></b> The mean area of affected lesions was 38.7 ± 19.8 mm², and cystic lesions were 8.5 ± 10.1 mm². VD, VL, and FD were significantly decreased in the cystic lesions compared to other affected lesions in the same eyes (<i>p</i> = 0.0010, <i>p</i> = 0.0001, and <i>p</i> = 0.0003, respectively) and in all eyes (<i>p</i> = 0.0281, <i>p</i> = 0.0050, and <i>p</i> &#x3c; 0.0001, respectively). VD in cystic lesions within the vascular arcade (25 eyes) correlated with best-corrected visual acuity on OCTA (<i>r</i> = −0.433, and <i>p</i> = 0.0492). <b><i>Conclusions:</i></b> Vascular structure in the cystic lesions was unpreserved compared to the other lesions in BRVO. These findings may help in understanding the pathophysiology of retinal edema in BRVO.