Surgery for epimacular membrane: impact of retinal internal limiting membrane removal on functional outcome.

Purpose: To examine eyes that underwent vitrectomy and peeling of epimacular membrane and to correlate the functional results with the presence or absence of an internal limiting membrane (ILM) in the histologic specimens.

Methods: Seventy-one eyes underwent vitrectomy and peeling of an epimacular membrane. These membranes were examined with a transmission electron microscope. Best-corrected visual acuities were recorded before macular surgery, 1 month after surgery, and at the final examination and were compared between group 1 (ILM removed) and group 2 (ILM not removed). The age, gender, status of the lens preoperatively, type of epimacular membrane (idiopathic or secondary), intraoperative and postoperative complications, and elapsed time between vitrectomy and cataract operation were recorded. All 71 eyes were pseudophakic at the final examination. The mean follow-up was 21 months.

Results: Long segments of ILM were found in the specimens from 55 (77%) of the cases. Final visual acuities were better in group 1 (ILM removed) than in group 2 (ILM not removed, P = 0.004). The visual gain was 3.1 lines on the Early Treatment of Diabetic Retinopathy Study chart in group 1 and 0.9 lines in group 2. At the last examination, a recurrent epimacular membrane was observed in 5 (9%) eyes of group 1 and 9 (56%) eyes of group 2.

Conclusion: ILM removal during surgery for epimacular membrane is associated with better final vision and a lower risk of recurrent epimacular membrane.