Predictive factors for better short-term outcome in idiopathic epiretinal membrane after pars plana vitrectomy

Abstract

Purpose : Recent progress in pars plana vitrectomy (PPV) has increased the patients who undergo PPV for idiopathic epiretinal membrane (ERM). We retrospectively evaluated the predictive factors for better short-term outcome in idiopathic ERM after pars plana vitrectomy.

Methods : The medical records of 77 eyes from 77 patients (26 men, mean age 71.1±8.0) who underwent PPV and cataract surgery for idiopathic ERM and mild cataract between March 2012 to September 2016 at the Vitreo-Retina Surgical Division Clinic at the Department of Ophthalmology, Keio University Hospital were reviewed. Those whose axial length was over 26.5mm were excluded. Preoperative ocular findings were compared with those at 1 week (77 eyes) or 1 month (57 eyes) after the surgery using commercially available software (IBM SPSS Statistics version 24.0), and results with P-values < 0.05 were considered significant.

Results : Mean best-corrected visual acuities (BCVAs) in logMAR before the surgery, 1 week and 1 month after surgery were 0.27±0.24, 0.21±0.28, and 0.15±0.25. The changes in BCVA 1 week or 1 month after surgery compared with preoperative BCVA were correlated with preoperative BCVA (correlation coefficient [CC]; -0.232 and -0.455, respectively) and axial length (CC; -0.355 and -0.261), both by Spearman’s test. The changes in BCVA at 1 week and 1 month were correlated (CC; 0.763). The BCVA at 1 week was associated with better preoperative BCVA (P<0.001), longer axial length (P=0.008), and absence of preoperative cystic changes in the inner retinal layer in the images of optical coherence tomography (OCT) within 1500-μm diameter of macular area (P=0.008) by multiple linear regression. The similar trends were also observed at 1 month. The eyes which had cystoid changes in the inner retinal layer of OCT image before the surgery had significantly shorter axial length (P=0.002) by Mann-Whitney U Test.

Conclusions : Preoperative better BCVA, longer axial length, and absence of cystoid changes in OCT images were predictive factors for better postoperative short-time outcome. Cystoid changes in the inner retinal layer of OCT image may be related to axial length. Further studies with more patients and longer observation are warranted.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.