Anatomical and Functional Recovery Kinetics After Epiretinal Membrane Removal

PURPOSE: To investigate the nature of anatomical and functional recovery kinetics after epiretinal membrane (ERM) removal. METHODS: The records of 42 patients (45 eyes) with idiopathic ERM treated with pars plana vitrectomy and surgical peeling of the ERM performed by a single surgeon at Massachusetts Eye and Ear between 2012 and 2017 were retrospectively reviewed. Outcome measures included spectral domain optical coherence tomography-measured central macular thickness (CMT) pre-operatively and at post-operative day 1, week 1, months 1, 3, 6, 12 and 24 as well as best-corrected visual acuity (BCVA). Correlations between baseline or early values and final anatomical and functional outcomes were investigated. RESULTS: Improvement in CMT was statistically significant after 1 week, 1, 3, 6, 12 and 24 months (p < 0.01). BCVA improvement was statistically significant after 1, 6, 12 and 24 months follow-up (p<0.01). The improvement of BCVA and CMT with time was found to be logarithmic (R(2) =0.96, R(2) =0.84) suggesting that early (<30 days) post-operative functional and anatomical changes may be predictive of long-term outcomes. Preoperative BCVA and CMT revealed a weak positive correlation with the respective BCVA and CMT at 24 months (R(2)=0.13 and R(2)=0.16). When plotted as a percentage of the fellow normal eye CMT, first week proportional improvement in CMT from pre-operative baseline was found to be correlated with final CMT proportional decrease (R(2)=0.72) suggesting that first week postoperative CMT could be predictive of final CMT. CONCLUSION: There is a logarithmic improvement in CMT and BCVA after ERM peel with BCVA improvement following the CMT improvement. Early (less than 30 days) post-operative anatomical changes can be predictive of long-term anatomical outcomes.