Changes in the size of the foveal avascular zone after vitrectomy with internal limiting membrane peeling for a macular hole

To determine the size of the foveal avascular zone (FAZ) before and after vitrectomy for a macular hole (MH). Retrospective case series study. Twenty-five eyes of 25 patients with a unilateral MH that had undergone vitrectomy with internal limiting membrane peeling were studied. The unaffected 17 fellow eyes were studied in the same way. En face images of the parafoveal region were obtained by optical coherence tomography angiography, and the images were used to measure the FAZ before and 1 month after the vitrectomy. The relationships between the different FAZ sizes and the ocular parameters were determined by Pearson product moment correlation analysis. Compared with the preoperative superficial FAZ (sFAZ), the postoperative sFAZ was significantly reduced (P < 0.001). The postoperative sFAZ was significantly smaller than that of the fellow eye (P < 0.001). The size of the postoperative sFAZ was significantly correlated with that of the preoperative sFAZ, the postoperative foveal thickness (FT), and the sFAZ of the fellow eyes (r = 0.520, P = 0.008; r = -0.515, P = 0.012; and r = 0.702, P = 0.002, respectively). The size of the postoperative deep FAZ (dFAZ) was significantly correlated with the postoperative FT and the dFAZ of the fellow eyes (r = -0.441, P = 0.035; and r = 0.499, P = 0.049, respectively). However, no significant correlation was found between the size of the postoperative FAZ and the size of the preoperative MH. MH closure leads to a significant decrease in the size of the FAZ symmetrical to the size of the fellow eye. The size of the postoperative FAZ is influenced by the postoperative FT independently of the size of the MH.