Purpose: To evaluate the visual outcomes after idiopathic epiretinal membrane surgery in glaucomatous and nonglaucomatous eyes and factors related to unfavorable outcomes in glaucomatous eyes.
Methods: This was a retrospective cohort study including patients undergoing idiopathic epiretinal membrane surgery with ≥12-month follow-up. Final visual acuity at pseudophakic status was compared among groups of glaucoma, glaucoma suspect, and nonglaucoma and correlated with optical coherence tomography and visual field characteristics in patients with glaucoma.
Results: Of the 314 patients enrolled, 31 had glaucoma and 22 were glaucoma suspect. Baseline visual acuity and central foveal thickness were similar across the groups. Most patients had improved/stable visual acuity postoperatively, with a lower proportion of 83.9% with glaucoma than 96.9% and 100% without glaucoma and glaucoma suspect, respectively (P = 0.002). The mean visual acuity did not change in the glaucoma group (from 6/29 to 6/23), but it improved from 6/25 to 6/12 (a gain of 16.7 approxETDRS letters) in nonglaucoma and 6/26 to 6/14 in glaucoma suspect (a gain of 14.0 approxETDRS letters) (both P < 0.001). The change of visual acuity was correlated with preoperative visual field defects (P < 0.001, r2 = 0.554). Patients with glaucoma with more advanced, fixation-threatening defects or temporally located inner nuclear layer microcysts were more likely to have worsened visual acuity.
Conclusion: Visual field testing is imperative for patients with glaucoma before idiopathic epiretinal membrane surgery for outcome assessment.