Outcomes of Pars Plana Vitrectomy for Epiretinal Membrane in Eyes With Coexisting Dry Age-related Macular Degeneration

Abstract

There has been limited evidence on the benefits of pars plana vitrectomy with membrane peel (PPV-MP) for epiretinal membrane (ERM) in eyes with dry age-related macular degeneration (AMD). We sought to assess anatomic and functional outcomes of PPV-MP for ERM in this subset of eyes. A retrospective cohort study. Patients with dry AMD who underwent PPV-MP for ERM from January 1, 2010, to December 1,2016. Visual acuity (VA) and central foveal thickness (CFT) as measured on spectral-domain OCT were recorded and analyzed for the preoperative, 6-month, and final follow-up visits. The presence of cystoid macular edema (CME) and ellipsoid zone (EZ) integrity were recorded and compared with postoperative imaging. Conversion to neovascular AMD in eyes for which at least 2 years of follow-up were available, as confirmed by either OCT and/or fluorescein angiography and documentation of treatment with intravitreal antivascular endothelial growth factor, was recorded and compared between case eyes that underwent PPV-MP versus fellow control eyes. Postoperative VA. A total of 38 eyes from 38 patients met the study criteria. There was a significant improvement in the median (interquartile range, [IQR]) logarithm of the minimum angle of resolution [logMAR] VA from 0.60 (IQR 0.46-1.00) (20/80, Snellen equivalent) at the preoperative visit, to 0.48 (IQR 0.30-0.70) (20/60, Snellen equivalent) at the 6-month follow-up visit (P= 0.04), and to 0.48 (IQR 0.30-0.70) (20/60, Snellen equivalent) at the final visit (P= 0.01). There was a significant median decrease in CFT at the final visit (P < 0.001) compared with the preoperative CFT. Only eyes with either CME or an intact EZ showed significant improvement in median logMAR VA at the final visit compared with the preoperative visit (P= 0.01 and P= 0.004, respectively). In a subgroup analysis of eyes for which a minimum of 2 years of follow-up were available, 4 of 25 (16.0%) vitrectomized eyes and 1 of 25 (4.0%) fellow control eyes progressed to neovascular AMD (P= 0.16). PPV-MP appears to confer anatomic and functional improvement in eyes with ERM and coexisting dry AMD. Moreover, greater preoperative CFT, the presence of CME, and an intact EZ were predictors of VA improvement in these eyes.