Abstract
Purpose :
Previous studies have classified epiretinal membranes (ERM) as well as abnormalities of the central foveal bouquet (CBA) in different stages based on their morphological appearance. Correlation of visual acuity with the different stages of this classification was shown. The presented study evaluates the change in classification following surgical removal of ERM.
Methods :
A retrospective study was conducted on 151 eyes being operated by 23g or 27g pars plana vitrectomy (PPV) and epiretinal membrane and internal limiting membrane (ILM) peeling from 2014 till 2018. Surgery was performed by two different surgeons (SM, n=93 and MBe, n=58). Eyes were evaluated by Heidelberg Spectralis Spectral Domain OCT (SD-OCT) were classified prior to surgery and at a mean of 3 months after surgery according to their morphological appearance. The classification ranges from “CBA 0” - indicating a normal subfoveal structure - to “CBA 3” - representing an acquired vitelliform lesion. ERM was classified ranging from “ERM 0” indicating the absence of ERM to “ERM 4” being the most severe form of ERM. Changes in morphology were correlated with visual acuity at different time points.
Results :
Before surgery 27.2 % (n=41) of the patients showed subfoveal changes with “CBA 1” being the most common (11.9%, n=18). All patients (n=151) showed ERM before surgery with “ERM 1” being the most common classification (28.5%, n=43). The mean BCVA was 0.42 (LogMAR) before and 0.19 (LogMAR) after the procedure indicating mean gain in vision of almost 2.5 lines (95% CI: 0.20-0.28; p<0.001). Patients who showed subfoveal changes prior to surgery had less BCVA increase than patients classified as CBA 0 (0.28 vs. 0.14 LogMAR; p=(p<0.001). Of all the patients with subfoveal changes, 68% had lower grading of CBA after the surgery than before (n=28; 95% CI; p<0.001). 100% of patients showed an improvement of their ERF grading, with 98.7% reaching grade “ERF 0” (n=151 vs n=149; 95% CI; p<0.001).
Conclusions :
Subfoveal changes secondary to ERM are a negative predictor for functional outcomes following PPV and ERM+ILM peeling for ERM. Classification of the CBA appears a valuable tool in pre-surgical evaluation.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.