Assessment of Macular Function by Multifocal Electroretinography Following Idiopathic Epiretinal Membrane Surgery with Internal Limiting Membrane Peeling

Abstract

Idiopathic epiretinal membrane (iERM) is the most common type of fibrocellular proliferation found at the vitreoretinal interface (VRI), which is significantly associated with aging.1 The symptoms associated with ERMs, especially metamorphopsia, can impair vision-related quality of life.7 OCT data can be qualitatively and quantitatively analyzed to show the morphologic features of iERM. 64 Multifocal ERG is an objective method to evaluate retinal function.13 This method is useful in assessing macular function before and after surgery in eyes with iERM.13 P1 wave changes reflect the inner retinal layer damage induced by ERM.108 Subtle mfERG abnormalities in the form of decreased P1 amplitude in ring 1 and 2 appear to persist up to 12 months after surgery, despite an improvement in visual acuity and reduced central foveal thickness.13 Pars plana vitrectomy (PPV) and ERM peeling have been used in patients with symptomatic visual disturbances as a standard procedure.112 Epiretinal membrane removal with or without ILM peeling can gradually improve visual acuity and metamorphopsia out to a 1-year follow-up.119 Both structural integrity assessed by OCT and functional assessment using mfERG are useful predictors of visual outcome after ERM surgery. 127 Recurrence of iERM has been reported in 5% to 21% of cases. Peeling of the ILM in the surgical management of symptomatic ERMs is controversial.11 The argument in favor of ILM peeling is that ILM peeling assists in the complete removal of an ERM and reduces recurrence.131 However, stripping of the ILM removes the Müller cell footplates causing Müller cell dysfunction.11