Relationship between long-term visual function and the ratio of foveal avascular zone area in eyes with macular hole and healthy fellow eyes

Purpose This study is to investigate the relationship between long-term changes in the foveal avascular zone (FAZ) and visual function of eyes with macular hole (MH) and compare the relationship between the FAZ of MH eyes and fellow eyes. Methods This study included 31 patients with unilateral MH who underwent vitrectomy and their fellow eyes. Best-corrected visual acuity (BCVA) and metamorphopsia were measured preoperatively and at 1, 3, 6, and 12 months postoperatively. We evaluated retinal parameters using optical coherence tomography (OCT) and the superficial FAZ using OCT angiography. The FAZ ratio was defined as follows: (preoperative FAZ area of the MH eye)/(FAZ area of the fellow eye). Results The preoperative FAZ area of MH eyes was 0.42 +/- 0.08 mm(2), which decreased to 0.24 +/- 0.07 mm(2) 1 month postoperatively (p < 0.001) and slightly increased to 0.25 +/- 0.06 mm(2) 12 months postoperatively (p = 1.000). The FAZ area did not differ significantly from that of fellow eyes (0.39 +/- 0.06 mm(2), p = 0.281). The FAZ area of MH eyes was not associated with visual function at any time point. The FAZ ratio showed a correlation with the preoperative, 6-month, and 12-month BCVA (r = 0.604, p < 0.001; r = 0.510, p = 0.003; and r = 0.475, p = 0.007, respectively). Conclusions A larger FAZ in the MH eye than that in the fellow eye is associated with poorer long-term visual acuity. The preoperative comparison of the FAZ of the MH eye with that of the fellow eye may be a biomarker for predicting long-term visual acuity.