Influence of macular microcirculation and retinal thickness on visual acuity in patients with branch retinal vein occlusion and macular edema

Abstract

To investigate perifoveal capillary blood flow velocity and retinal thickness at the central fovea in patients with branch retinal vein occlusion (BRVO) and macular edema and to assess their relation with visual acuity and visual prognosis. Eighteen patients with BRVO and 16 healthy volunteers were compared. Perifoveal capillary blood flow velocity was measured on fluorescein angiograms with a scanning laser ophthalmoscope by the tracing method. Retinal thickness was measured at the central fovea by optical coherence tomography. Best-corrected visual acuity (BCVA) was determined. BCVA differed significantly between patients and controls (P < 0.0001). Among patients, BCVA was negatively correlated with perifoveal capillary blood flow velocity by univariate analysis (r = -0.7916, P < 0.0001), and positively correlated with retinal thickness at the central fovea (r = 0.8970, P < 0.0001). Multivariate analysis showed that retinal thickness at the central fovea was the only independent determinant of BCVA (P < 0.0001). In patients with BRVO, BCVA was more strongly influenced by retinal thickness at the central fovea than by perifoveal capillary blood flow velocity.