Refractive shift following the combination of phacoemulsification, intraocular lens implantation and vitrectomy in the eyes with idiopathic macular epiretinal membrane / 中华实验眼科杂志

ABSTRACT

Background Idiopathic macular epiretinal membrane (IMEM) combined with age-related cataract (ARC)is a common eye disease and the primary managing approach is the combination of phacoemulsification,intraocular lens (IOL) implantation and vitrectomy.However,whether the ocular length measured by IOL Master is accurate for the calculation of IOL refraction in the eye with IMEM remains unclear.Objective The aim of this study was to evaluate the refractive outcomes of combination surgery of phacoemulsification,IOL implantation and vitrectomy in IMEM eyes.Methods A prospective cohort study was designed.Forty-two eyes of 42 patients with IMEM combined with ARC (IMEM+ARC group) were enrolled in Peking University People's Hospital and the combination of phacoemulsification,IOL implantation and vitrectomy was performed from September 2010 to August 2011,and 47 eyes of 47 patients with ARC were included for the phacoemulsification combined with IOL implantation in the corresponding period (ARC group) under the approval of Ethic Committee of Peking University People's Hospital and informed consent of the patients.Ocular length and corneal curvature were measured using IOL Master,and the expected IOL diopter was calculated with SRK-T formula.Regular eye examination and medical optometry were performed 1 month and 3 months after operation to obtain the actual diopter and the refractive error.The outcomes were compared between the two groups.The correlations of refractive error with change of fovea thickness were evaluated after operation in the IMEM+ARC group.Results There were no statistically significant differences in the age,ocular length and corneal curvature between the two groups before operation (P =0.863,0.704,0.770).The visual acuity was improved 3 months after operation in comparison with before operation in both groups (P=0.001,0.000).The negative diopters were obviously higher 1 month and 3 months after operation than those before operation in both groups (all at P＜0.001),but no significant difference was seen between the IMEM+ ARC group and ARC group (Fgroup =0.417,P =0.520).The diopter deviations 1 month and 3 months after operation were (-0.727±0.666)D and (-0.628±0.627)D in the IMEM+ARC group,and those in the ARC group were (-0.664±0.644) D and (-0.642±0.550) D,showing insignificant differences between the two groups (Fgroup =0.036,P =0.849 ; Ftime =1.523,P =0.221).In IMEM + ARC group,the macular fovea thickness was (474.89 ± 135.76)μm in preoperation,and the shift values of macular fovea thickness were (-83.84 ±91.12)μm and (-158.53±113.03) μm in postoperative 1 month and 3 months.No positive correlations were presented between the diopter deviations and change of fovea thickness 1 month and 3 months after operation in the IMEM+ARC group (r=0.200,P =0.229 ; r =0.065,P =0.698).Conclusions Myopia shift after operation is similar in the IMEM combined with ARC patients to the only ARC patients,suggesting that the ocular length and corneal curvature measured by IOL Master is not affected by epiretinal membrane.