AIM:To compare frequency domain optical coherence tomography(OCT)images of idiopathic macular epiretinal membrane(ERM)with those of secondary ERM and analyze the influence on visual acuity

METHODS:Clinical data of 92 idiopathic ERM patients(112 eyes)and 78 secondary ERM patients(96 eyes)diagnosed with slit lamp microscope, fundus fluorescein angiography(FFA)and OCT. The morphological changes of ERM, central foveal thickness in all cases were recorded and analyzed by OCT.

RESULTS: ERM was visible on OCT as high reflective tissue which was focal points of attachment or globally adherent to the underlying retina. In part of fovea, the depth decreased, the thickness increased and macular became edema. The mean retina thickness in patients with idiopathic ERM was 398.32±112.07μm and the mean thickness of ERM was 52.28±9.65μm vs 416.87±104.17μm and 57.05±10.33μm in patients with secondary ERM respectively, there was no statistical difference between them(P>0.05). In the same range of visual acuity, there was no statistical difference(P>0.05)between idiopathic ERM group and secondary ERM group,but between the different range of visual acuity, the thickness of central fovea of macula was significantly different(P<0.05).

CONCLUSION: OCT can display the ERM and the pathological changes of macular tissues,frequency domain OCT was a particularly useful in the diagnosis of ERM.