Session Title: Vitreoretinal Surgery V
Session Date/Time: Sunday 20/09/2015 | 11:00-13:00
Paper Time: 12:28
First Author: : I.Corcóstegui SPAIN
Co Author(s): : I. Herrera G. Castiella J. Araiz G. Corcóstegui
PURPOSE:To describe the multifocal electroretinogram (mERG) changes of the macula and to analyze the thickness of the macular layers long term after Brilliant blue assisted (BBG) epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling.
Prospective interventional comparative case series. The macular function was assessed with mERG and the retinal layers were analyzed with a spectral optical coherence tomography (OCT).
Ten eyes of 10 patients with idiopathic ERM underwent a pars plana vitrectomy with BBG assisted ERM and ILM removal. Visual acuity (VA), mERG and OCT were performed preoperatively and postoperatively at 1, 3, 6 and 24 months. Additionally, 48 months after the surgery a high definition OCT of the macula at the foveal level was performed and compared with the contralateral eye.
There was a significant improvement of the mean VA and the mean macular thickness in all the analyzed postoperative periods compared to baseline (p<0.05). Fourty eight months after surgery 1 of the patients showed a lack of restoration of the macular layers with a thick inner retinal layer (IRL) and lower visual acuity. The mERG response amplitudes of the central macular rings suffered a slight decrease (Wilcoxon signed rank test p > 0.05) after the surgery that remained stable during all the postoperative periods.
In this short case series a lack of restoration of the IRL was associated with a thicker retina and a lower visual acuity. The slight functional macular changes detected with the mERG were limited to the central macular surface that had previously undergone an ILM peeling. Two years after surgery the changes remained the same with no sign of recovery. ILM peeling can cause slight but permanent macular functional changes that are not related with VA improvement.