Correlation of foveal avascular zone size with visual acuity and metamorphopsia in idiopathic macular epiretinal membrane eyes using optical coherence tomography angiography / 中华眼底病杂志

ABSTRACT

Objective To analyze the correlation of foveal avascular zone (FAZ) size with visual acuity and metamorphopsia in idiopathic macular epiretinal membrane (IMEM) eyes.Methods This is a cross-sectional study, including 43 patients (43 eyes) with IMEM (IMEM group) and 35 health subjects (35 eyes) as control group. The best corrected visual acuity (BCVA) was measured using the international standard visual acuity chart, and the results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. The severity of metamorphopsia was measured using M-charts. The FAZ areas were estimated with optical coherence tomography angiography (OCTA) in both the superficial and deep capillary plexus layers. The central macular thickness (CMT) was assessed with spectral-domain optical coherence tomography. There was no difference of logMAR BCVA and CMT between two groups (Z=?7.379, ?7.560;P<0.001). The differences of FAZ areas between the two groups were analyzed. The correlative analysis was performed to investigate the relationship between FAZ areas and visual acuity as well as metamorphopsia.Results The FAZ area in superficial and deep capillary plexus in IMEM group were smaller than those in control group (t=?30.316, ?27.606;P<0.001). In IMEM group, the mean M-score was 0.41±0.32; the horizontal and vertical M-score were 0.49±0.40 and 0.32±0.29, respectively. The horizontal M-score was higher than vertical M-score with the significant difference (Z=?2.000,P=0.046). In IMEM group, the FAZ area in superficial capillary plexus correlated inversely with metamorphopsia (r=?0.709,P<0.001); the FAZ area in deep capillary plexus correlated inversely with metamorphopsia and BCVA (r=?0.533, ?0.838;P<0.001).Conclusions The FAZ areas are significantly decreased in IMEM eyes compared with normal eyes. Both superficial and deep FAZ areas are correlated with metamorphopsia, and deep FAZ area is also correlated with BCVA.