Qi Y, Yu Y, You Q, et al. - This retrospective case series study was undertaken to determine if the preoperative hole diameter ratio (HDR) is a predictive factor for the postoperative anatomical outcome for stage III or IV idiopathic macular holes (IMHs). One hundred one eyes of 101 patients with stage III (n = 65,64.4%) or IV (n = 36, 35.6%) IMH underwent PPV in combination with ILM peeling and air tamponade. Findings suggested that after vitrectomy combined with ILM peeling and air tamponade, HDR < 0.6(A-type IMH) can be a predictive factor for good anatomical outcome in stage III or IV IMHs. On preoperative OCT images, it can be easily calculated and intuitively observed, and can help doctors and patients predict surgical prognosis for stage III or IV IMHs.