Anatomical and Functional Recovery Kinetics After Epiretinal Membrane Removal

To investigate the nature of anatomical and functional recovery kinetics after epiretinal membrane (ERM) removal.

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.

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 (R² =0.96, R² =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 (R²=0.13 and R²=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 (R²=0.72) suggesting that first week postoperative CMT could be predictive of final CMT.

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.