Epiretinal macular membranes in eyes with attached posterior cortical vitreous

Background: The authors define the clinical and anatomic characteristics of patients who had epiretinal membrane formation and traction over the macula in the absence of vitreous detachment from the retina. Methods: Patients were treated and followed by one surgeon (JCF). All patients had epiretinal membrane formation over the macula without vitreous detachment. The clinical and surgical findings of these patients were compared along with histopathologic examination of the removed epiretinal membranes and posterior cortical vitreous. Results: Fourteen patients were identified over a 9.75-year period. All patients had a thin and transparent-or at most minimally translucent-membrane overlying the posterior pole causing traction. The membrane appeared continuous with the posterior hyaloid face. At vitrectomy, no vitreous detachment was found in any eye. Transmission electron microscopy of all three specimens tested found collagen of less than 16 nanometers in diameter, consistent with native vitreous collagen. After surgery, visual acuity improved in 13 of 14 eyes, was 20/50 or better in 12 eyes, and was 20/25 or better in 7 eyes. Conclusion: Epiretinal membrane formation can occur in eyes without vitreous detachment probably because of cellular growth along the posterior hyaloid face. Such eyes respond particularly well to surgery.