Evaluation of Shape of Foveal Avascular Zone by Optical Coherence Tomography Angiography in Eyes With Branch Retinal Vein Occlusion

Purpose: To determine the relationship between morphological parameters of the foveal avascular zone (FAZ) in the optical coherence tomography angiographic (OCTA) images and the best-corrected visual acuity (BCVA) in branch retinal vein occlusion (BRVO). Methods: This was a retrospective cross-sectional study. Eyes with BRVO without apparent macular edema were studied. The superficial FAZ in 3 × 3 mm OCTA images were delineated manually. The size and shape, the circularity and axial ratio, of the FAZ were determined, and the values were compared to that of the controls. The correlation of these parameters with the BCVA was analyzed. Results: The mean FAZ area was larger in BRVO eyes than in controls, but the larger size was not correlated with the BCVA (BRVO, 0.49 ± 0.12 mm 2 ; control, 0.38 ± 0.12 mm 2 ; P = .135). The axial ratio of the BRVO eyes was significantly larger than that of controls ( P < .001). The axial ratio was significantly correlated with BCVA ( R = .382, P = .050). Although the circularity was significantly smaller in the BRVO eyes than that in controls ( P < .001), it was not significantly correlated with the BCVA. Conclusion: The shape of the FAZ would be a more appropriate parameter than the size in determining BCVA in eyes with BRVO.