Prognostic Factors for Functional Improvement After Pars Plana Vitrectomy and Epiretinal Membrane Peeling

Abstract

INTRODUCTION: Earlier studies confirmed that the integrity of the photoreceptor layer may influence visual outcome after pars plana vitrectomy (PPV) and epiretinal membrane (ERM) peeling. Recently, distortion of inner retinal architecture has been studied. Our study examines prognosis factors for visual improvement post-surgery in a Portuguese tertiary hospital.
METHODS: The medical records of 234 patients were retrospectively reviewed. Forty-nine eyes of 49 patients with idiopathic ERM treated by PPV and membrane peeling were included in the study. Govetto classification, ERM connection type, central foveal subfield thickness (CST), maximum retinal thickness (MRT), intraretinal cystoid changes, inner retinal changes (presence and thickness of ectopic inner foveal layer (EIFL), ganglion cell-inner plexiform layer (GC-IPL) thickness, and disorganization of retinal inner layers (DRIL)) and outer retinal changes (cotton ball, foveolar detachment, acquired vitelliform lesion, integrity of the ellipsoid zone and inter-digitation zone) were studied pre-operatively, at 3, 6 and 12 months after surgery. Correlations between baseline OCT measures and visual outcome were analyzed.
RESULTS: No correlation was found between age and concurrent cataract surgery on post-op best-corrected visual acuity (BCVA). A positive correlation was established between pre-operative and post-operative BCVA. Pre-operative CST had a significant inverse correlation with BCVA at all follow-up timepoints. Govetto score showed a positive correlation with pre-operative CST, MRT, and DRIL score, and negative correlation with pre-operative and post-operative BCVA. The presence of DRIL at baseline predicted decreased BCVA at 3-month and 1-year post-operative assessments. Pre-operative EIFL thickness did not significantly influence BCVA at any evaluation point. Eyes with pre-operative intraretinal cysts showed significantly lower BCVA at baseline and at the 12-month follow-up. Disruptions in the IZ and EZ lines pre-operatively were associated with lower baseline BCVA and poorer post-operative visual outcomes. The other evaluated parameters did not influence the final BCVA.
CONCLUSION: The study reveals the influence of preoperative BCVA, CST, DRIL, intraretinal cysts, IZ and EZ disruptions, and Govetto score on postoperative visual acuity in iERM patients. These findings emphasize the value of comprehensive preoperative retinal assessments for improved surgical decision-making in iERM treatment.