Photoreceptor outer segment length: a prognostic factor for idiopathic epiretinal membrane surgery.

Purpose: To investigate prognostic factors for visual improvement in patients undergoing vitrectomy for epiretinal membrane (ERM) using spectral domain (SD) optical coherence tomography (OCT).

Design: Prospective cohort study.

Participants: A total of 41 eyes of 38 patients.