AIM: To analyze the effects of vitrectomy and macular epiretinal membrane dissection combined with or without internal limiting membrane(ILM)peeling on choroid thickness, vision and metamorphopsia in patients with idiopathic macular epiretinal membrane(IMEM).

METHODS: Totally 88 patients(88 eyes)with IMEM admitted to the hospital were selected between January 2016 and January 2020. They were divided into group A and group B by random number table method with 44 eyes in each group. Patients in group A were treated with vitrectomy and macular epiretinal membrane dissection combined with ILM peeling, while patients in group B were treated with vitrectomy and macular epiretinal membrane dissection. The choroid thickness, vision, metamorphopsia, central macular thickness(CMT), ellipsoid zone(EZ)continuity were compared between the two groups.

RESULTS: Compared with preoperative, the sub-foveal choroidal thickness(SFCT), choroidal thickness 1 000μm from nasal side central of fovea(NFCT)and choroidal thickness 1 000μm from temporal side central of fovea(TFCT)were significantly reduced in the two groups at 3mo and 6mo after operation(P<0.05), but there was no statistically significant difference between the groups(P>0.5). Compared with preoperative, the best corrected visual acuity(BCVA)LogMAR was reduced, while mean sensitivity(MS)was increased in the two groups. The number of scotoma points(SP)increased in group A and decreased in group B. Group A had significantly lower MS and higher SP than group B at 1mo, 3mo, and 6mo after operation(P<0.05). Compared with preoperative, the M scores(Angle of view when horizontal and vertical variability begins to disappear)and average M scores of the two groups were significantly reduced at 3mo and 6mo after operation, without statistically significant differences between the groups(P>0.05). Compared with preoperative, CMT was significantly reduced in the two groups at 1, 3 and 6mo after operation. The ratio of EZ continuity in group A at 1mo after operation was significantly lower than that before operation. The CMT of group A was larger than that of group B at 3mo and 6mo after operation(P<0.05). No statistically significant differences were found in the ratio of EZ continuity and the incidence of complications between the groups(P>0.05).

CONCLUSION: Vitrectomy and macular epiretinal membrane dissection combined with or without ILM peeling both can improve vision and metamorphopsia in patients with IMEM, with similar effects on choroid thickness and safety. However, combined use of ILM peeling will lower MS and increase SP as well as CMT. Therefore, it has no significant advantages in the treatment of patients with IMEM.