Visual prognosis correlated with the presence of internal-limiting membrane in histopathologic specimens obtained from epiretinal membrane surgery.

Forty-one patients with a unilateral, macular epiretinal membrane (ERM) underwent pars plana vitrectomy and membrane peeling to improve the visual acuity. The authors retrospectively reviewed the histopathology of the vitrectomy specimen in each instance to determine whether the presence of internal-limiting membrane (ILM) had an adverse effect on visual acuity. Eleven specimens contained long segment of ILM, as determined by light microscopy. With a minimum of 6 months of follow-up, none of these 11 eyes achieved a visual acuity of better than 20/60. Of 30 eyes that did not have ILM present, 41% achieved a visual acuity of 20/60 or better. Overall, 29% of the eyes in the entire series achieved 20/60 or better visual acuity. The difference between the group with ILM versus that without ILM was statistically significant (P = 0.01). The presence of long segments of ILM within the histopathologic specimen after vitreous surgery for removal of a macular ERM appears to indicate a less favorable visual outcome.