Purpose: To assess macular function after vitrectomy and membrane removal in eyes with idiopathic epiretinal membrane by means of multifocal electroretinogram (mfERG).

Methods: Visual acuity, macular thickness measured by optical coherence tomography, and mfERG recordings were achieved for 14 eyes of 14 patients who having idiopathic epiretinal membrane. All exams were performed before epiretinal membrane surgery and 1, 3, and 6 months after surgery.

Results: Amplitude of mfERG were 139.18 ± 73.63 nV/deg2, 114.25 ± 29.16 nV/deg2 and 134.66 ± 69.64 nV/deg2 at before surgery, after 1 month and 3 months, respectively. Implicit time were 75.23 ± 31.34 nV/deg2, 66.20 ± 25.04 nV/deg2 and 74.79 ± 15.47 nV/deg2 at before surgery, after 1 month and 3 months, respectively. There were no significant changes in amplitude and implicit time measured by mfERG before and after the surgery (p>0.05). There were no significant correlations between the changes of amplitude and implicit time and visual acuity and macular thickness change.

Conclusions: Changes in mfERG recordings were not concluded to be useful for predicting clinical prognosis after epiretinal membrane surgery in this study.