AIM: To evaluate the disruption degree of macular fovea structure by pre-operation SD-OCT examination and establish a new method of IMEM. Thus, to analysis the value of this method for predicting the visual functional prognosis of cataract patients complicated with idiopathic macular epiretinal membrane(IMEM)after cataract surgery alone.

METHODS: Totally 64 patients(80 eyes)diagnosed as cataract with IMEM, who simply underwent phaco cataract extraction combined with intraocular lens implantation were included in this study. These patients were admitted in Shenzhen Eye Hospital from October 2017 to November 2018. IMEM was divided into 4 stages based on the damage degree of macular fovea structure by pre-operative SD-OCT examination. The best corrected visual acuity(BCVA), mean retinal sensitivities(MS), central macular thickness(CMT)and the progression rate of IMEM in all the patients were compared and analyzed before and 3mo after the cataract operation.

RESULTS: With the IMEM grade rised, the epiretinal membranes became more obvious, the disruption of retinal layers and loss of the foveal depression became more serious on the SD-OCT image. The LogMAR BCVA of pre-operation and 3mo after cataract surgery progressively rised with the increasing of IMEM grade, and the differences were statistically significant(F=37.72, 26.43, P<0.001). Otherwise, The MS of pre-operation and 3mo after cataract surgery progressively declined with the increasing of IMEM grade, and the differences were statistically significant(F=43.77, 28.96, P<0.001). The change of CMT was not consistent with the progression rate of IMEM in 3mo after operation. There was no significant difference in CMT(P>0.05), but the progression rate of IMEM was increased significantly with the IMEM grading(χ²_Trend=12.59, P<0.001).

CONCLUSION: The new classification method was created for IMEM by SD-OCT will help to predict the visual functional prognosis for cataract patients complicated with IMEM after cataract surgery.