Relationship between optical coherent tomography and multifocal electroretinogram in idiopathic macular epiretinal membrane

ObJective To investigate the features and correlation of frequency-domain optical coherent tomography (fdOCT) and multifocal electroretinogram (mfERG) in patients with idiopathic macular epiretinal membrane (IMEM),and visual acuity.Methods Thirty patients with unilateral IMEM were collected,which diagnosed by visual acuity,ophthalmoscope,OCT or fundus fluorescein angiography in Tianjin Eye Hospital from January to May of 2012,and then checked mfERG.The data from contralateral normal eyes was used as the control group.The relationship between the results of macular morphology and function were analyzed,and the effect on visual acuity was also included.Results The best-corrected visual acuities of 30 eyes ranged from 0.02 to 1.0 (average 0.62±0.27).fdOCT revealed that there was significantly statistical difference in the retinal thickness about macular fovea,parafovea and perifovea between diseases eyes and contralateral eyes (P ＜0.05).mfERG revealed that there was a significant difference in the amplitude densities of PI wave and the latencies of N1 wave at ring 1 to 5 (P ＜0.05).There was no statistical difference in the amplitude densities of N1 wave except ring 1 and 2.The foveal thickening was negatively correlated with visual acuity (r =-0.615,P =0.001).The latencies of PI,N1 wave at ring 1 had effect on visual acuity (P ＜0.05),however,the amplitude densities were not.Conclusions The visual acuity can be worse with the increase of central retinal thickness which caused by IMEM,but that is inconsistent with the degree of functional impairment.The combination of OCT and mfERG have better evaluation in the effect of IMEM on macular anatomical and functional outcomes. Key words: Idiopathic epimacular membrane;  Optical coherent tomography;  Multifocal electroretinogram;  First order kernel