AIM: To explore the risk factors that affect visual function recovery in patients with idiopathic macular epiretinal membrane(IMEM)undergoing internal limiting membrane peeling(ILMP).

METHODS: This study retrospectively reviewed 118 patients(118 eyes)with IMEM who underwent ILMP in the hospital between January 2016 and April 2020. The patients were followed up for 6mo after surgery to evaluate curative effect. Changes in visual acuity before surgery and at 1, 3 and 6mo after surgery, metamorphopsia degree, mean central foveal thickness and volume of macular area were observed. The correlation of mean central foveal thickness and volume of macular area before and after surgery with postoperative visual acuity and metamorphopsia scores was analyzed. The risk factors for poor visual function recovery after surgery were evaluated.

RESULTS: In this study, 96 eyes obtained good visual function recovery, and the improvement rate was 81.4%. At 1, 3 and 6mo after surgery, visual acuity was significantly improved(P<0.05), metamorphopsia score in horizontal direction, mean central foveal thickness and volume of macular area were significantly reduced(P<0.05). The mean central foveal thickness and volume of macular area before surgery and at 6mo after surgery were negatively correlated with visual acuity at 6mo after surgery(P<0.05), but positively correlated with metamorphopsia score in horizontal direction(P<0.05). The course of IMEM, preoperative corrected visual acuity, preoperative horizontal or vertical metamorphopsia, and preoperative macular edema were influencing factors of visual function recovery after surgery(all P<0.05). Poor preoperative corrected visual acuity(OR=3.062), horizontal metamorphopsia(OR=2.438)and preoperative macular edema(OR=2.000)were risk factors for poor visual function recovery.

CONCLUSION: The curative of ILMP is effect on IMEM, which can effectively improve visual acuity of operative eyes and reduce metamorphopsia. The longer the course of disease, the worse the preoperative corrected visual acuity, and the more severe the preoperative metamorphopsia, the worse the visual function recovery in patients with preoperative macular edema after ILMP.