Correlation between foveal cone outer segment tips line and visual recovery after epiretinal membrane surgery.

Purpose: To determine whether there is a significant correlation between the integrity of the foveal microstructures and the best-corrected visual acuity (BCVA) after pars plana vitrectomy for epiretinal membrane (ERM) removal.
Methods: This was a retrospective, interventional case series. Forty-six eyes of 45 patients with an ERM underwent vitrectomy. The foveal area was examined by spectral-domain-optical coherence tomography (SD-OCT) preoperatively and postoperatively. The correlation between the length of the photoreceptor cone outer segment tips (COST) line defect, the inner segment/outer segment junction (IS/OS) line defect, the external limiting membrane (ELM) line defect, and the BCVA was determined.
Results: The length of the COST line defect was significantly correlated with the BCVA at postoperative 1, 3, 6, 9, and 12 months (P < 0.001 for all). Forward stepwise regression analyses showed that the postoperative BCVA was significantly correlated with the length of COST line defect (P < 0.001) but not with the IS/OS line and ELM line defects for up to 6 months. The preoperative length of the COST line defect was significantly correlated with the postoperative BCVA at 12 months (P = 0.005), but the lengths of the IS/OS line defect and ELM line defect were not. The factor that best predicted the postoperative BCVA was the length of the preoperative COST line defect (P = 0.04) but not the preoperative BCVA (P = 0.69).
Conclusions: The recovery of the foveal COST line defect is correlated with the BCVA after ERM surgery. The length of the preoperative COST line defect can predict the potential foveal function. (ClinicalTrials.gov number, NCT01549249.).