To report a case of visual field defect developed after internal limiting membrane (ILM) peeling in a patient with macular epiretinal membrane (ERM).

A 33-year-old female without a history of specific diseases presented with a gradually decreased visual acuity in the right eye for 3 years. The patient was diagnosed as having macular ERM and underwent vitrectomy. During ILM peeling, retinal hemorrhage occurred in the superior region of macula, which spontaneously disappeared 2 weeks after surgery. Transmission electron microscopy showed Müller cell end feet with damaged appearance adherent to the ILM. At 3 months after surgery, the patient developed retinal nerve fiber layer (RNFL) defect in the area where the spot retinal hemorrhage had occurred. Optical coherence tomography showed focal RNFL thinning in the superotemporal region. The automated perimetry revealed corresponding inferior nasal step and scotomas in the right eye. Intraocular pressure was normal throughout the follow-up period and there was no evidence of glaucomatous optic disc change.

The results obtained from the patient in the present study indicated that visual field defect may be the result of a mechanical damage to the RNFL during ILM peeling.