Visual acuity appears to stabilize 12 months after vitrectomy for idiopathic epiretinal membrane

This study retrospectively evaluated the long-term association between macular thickness measured by optical coherence tomography (OCT) and visual outcome following vitrectomy for idiopathic epiretinal membrane.

The authors reviewed medical records of 52 patients who underwent pars plana vitrectomy at one hospital and were followed for more than 12 months. They found that most of the changes in BCVA and central macular thickness took place during the first three months after surgery and reached a plateau at 12 months. However, a significant reduction in central macular thickness was observed after more than 12 months after surgery. Final BCVA was correlated significantly with preoperative BCVA and central macular thickness and early postoperative central macular thickness.

The authors conclude that after removal of the confounding effect of cataract, 12 months may be sufficient to reach final BCVA after vitrectomy for epiretinal membrane but more time is needed to achieve final central macular thickness. Their calculations indicate that central macular thickness of less than 369 µm at one month after surgery was predictive for a good visual outcome. The authors recommend that surgeons follow up with their patients for at least one year to measure a final visual outcome and longer for final macular thickness. Because of the significant correlation between final BCVA and early postoperative central macular thickness, they say that serial postoperative OCT may be needed to predict visual outcome, especially at one month after surgery.