Functional and morphological assessment of patients with idiopatic epiretinal membrane after surgical treatment

Abstract

Purpose : To evaluate macular function before and after successful surgical peeling of idiopathic epimacular membranes (ERM) by multifocal electroretinogram (mfERG) and microperimetry (MP).

Methods : We analyzed 26 patients diagnosed with unilateral idiopathic ERM and operated by the same surgeon for ERM removal in our Eye Clinic. All patients underwent standard 23-gauge vitrectomy with triamcinolone assisted ERM/ILM removal. Exclusion criteria were: secondary ERM; refractive error ≥ 6D and other ocular pathologies. All the patients were invited to visit at baseline and at 4 and 12 months post-treatment, including: best corrected visual acuity (BCVA), dilated fundus examination, optical coherence tomography (OCT), MP and mfERG. BCVA, MP and mfERG parameters were compared using paired t-tests corrected for multiple comparisons by Bonferroni correction. A p-value less than 1.67% was considered as significant. The data are reported as mean ± standard error of mean. The study adhered to the tenets of the Declaration of Helsinki and received approval by the Local Ethics Committee.

Results : Twenty-six patients (aged: 70.0±1.6 years) underwent surgical treatment of ERM. 12 eyes with ERM were pseudophakic before surgical treatment and 14 patient underwent also phacoemulsification in the treated eyes. All patients underwent at least one post-operative visit. Improvements of visual functionality were observed in all the patients. BCVA significantly (p<0.001) improved from baseline (0.59±0.05) to 4 (0.25±0.05) and 12 (0.10±0.03) months time-points. Moreover, Macular Sensitivity (MS) increased from 10.2±0.8 dB before surgery to 12.4±0.8 dB at 4 months after treatment (p=0.02) and to 14.5±0.9 dB at the last time-point (p=0.005). The mfERG responses showed a significant increase of response densities in the first ring at 4 months from the surgery compared to baseline (from 16.8±5.5 to 33.5±7.1; p=0.01). Finally, a further significant increase was observed also in the second ring at the last time-point (57.9±7.0) compared to baseline (26.5±4.3;p<0.001) and 4 month (35.3±3.8;p<0.01).

Conclusions : The macular peeling in patients with ERM is safe and effective, inducing both anatomical and functional recovery. The electrical retinal response density of macular retina gradually improved after ERM peeling, suggesting a progressive recovery of retinal functionality.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.