Abstract
Purpose: :
To investigate the correlation between mfERG responses and visual acuity outcome after surgery for idiopathic macular hole (MH) and epiretinal membrane (ERM).
Methods: :
Prospective, open label study including 22 eyes from 22 patients that underwent cataract surgery plus pars plana vitrectomy with macular peeling for MH (n=14) or ERM (n=8). Comprehensive ophthalmological evaluation including ETDRS best-corrected visual acuity (BCVA) plus spectral domain OCT (Heidelberg engineering; Heidelberg - Germany) and mfERG (Diagnosys LLC; UK) were performed before (baseline), 2 and 6 months after surgery.
Results: :
MH was considered closed in all eyes 6 months after surgery (Imai criteria). Mean ± SD BCVA (logMAR) at baseline was 0.86 ± 0.17 (20/144) for MH and 0.56 ± 0.12 (20/73) for ERM. The average intra-individual BCVA improvement (logMAR) was 0.11 (P=0.0327) for MH and 0.25 (P=0.0152) for ERM. A statistically significant correlation was observed between mfERG first kernel response amplitude density (P1 average of the first 3 concentric rings: 3RP1) and the BCVA improvement (r= 0.51422; P=0.0144). The mean ± SE 3RP1 for eyes that showed BCVA improvement of 2 lines or more was 13.5 ± 1.5 nV/deg2, while for eyes that not reach this BCVA improvement it was 9.8 ± 1.2 nV/deg2 (t-Test; P=0.0422).
Conclusions: :
Retinal function assessed with mfERG might be considered as predictor of visual acuity outcome after macular surgery for BM and ERM. Reductions on mfERG responses might signalize outer retinal impairment that indicate lower chances of BCVA improvement after macular peeling, even in cases with satisfactory anatomical results.
Keywords: macular holes • electroretinography: clinical • visual acuity