目的：对比研究23G和20G玻璃体切除手术(pars plana vitrectomy，PPV)联合内界膜剥除、白内障超声乳化人工晶状体植入术治疗合并白内障的特发性黄斑前膜(idiopathic macular epiretinal membrane，IMEM)的临床疗效。

方法：采用非随机对照回顾性研究。对合并白内障的IMEM患者45例45眼，分别实施23G和20G PPV联合内界膜剥除、白内障超声乳化合并人工晶状体植入术，术后随访90d。对比术中玻璃体切除时间、剥膜时间、平均超声能量(average ultrasound energy，AVE)和有效超声乳化时间(effective phacoemulsification time，EPT)，术前与术后1、7d的眼压，术前与术后30、90d最佳矫正视力(best corrected visual acuity， BCVA)和黄斑中心凹视网膜厚度，术后90d角膜内皮细胞计数。

结果：23G组玻璃体切除时间为12.57±1.35min，20G组玻璃体切除时间为17.30±1.19min，两者比较差异有显著统计学意义(t=-12.488，P<0.01)。两组剥膜时间比较差异无统计学意义(t=-0.68，P=0.500)。术后1d，23G组的眼压略低于20G组，差异有显著统计学意义(t=-2.345，P=0.024)。术后两组患者的BCVA和黄斑中心凹视网膜厚度均较术前明显改善。两组患者的眼压、BCVA和黄斑中心凹视网膜厚度组间差异均无统计学意义(F=0.465、1.895、0.689，P=0.499、0.176、0.411)。两组患者的眼压、BCVA和黄斑中心凹视网膜厚度不同时间点差异均有统计学意义(F=291.245、103.06、665.402，P<0.01)。23G和20G不同手术方式与不同时间点的眼压有交互作用(F=13.245，P<0.01)，而不同手术方式与不同时间点的BCVA和黄斑视网膜厚度无交互作用(F=1.212、2.293，P=0.283、0.129)。两组的平均超声能量和有效超声时间差异无统计学意义(t=-1.186、-0.737，P=0.242、0.465)。术后90d，23G组患者的角膜内皮细胞计数略高于20G组，差异有统计学意义(t=2.049，P=0.048)。

结论：23G PPV联合白内障超声乳化人工晶状体植入术治疗合并白内障的IMEM效果确切。和20G相比，23G PPV手术时间短，对角膜内皮细胞损伤小，但存在术中隐性切口漏造成术后一过性低眼压的可能。

METHODS: Totally 45 eyes of 45 patients with macular epiretinal membrane and cataract were enrolled in this retrospective non-randomized controlled clinical study. All eyes were treated with PPV combined with internal limiting membrane peeling, phacoemulsification and intraocular lens implantation. There were 20 eyes in 23G PPV group, and 25 eyes in 20G PPV group. The best corrected visual acuity(BCVA), intraocular pressure(IOP), counting of corneal endothelial cells(CEC)and central retinal thickness(CRT)were examined before surgery. BCVA results were converted to the logarithm of the minimum angle of resolution(LogMAR)visual acuity. All operations were performed by the same doctor. Operation time for vitrectomy and membrane peeling, average ultrasound energy(AVE)and effective phacoemulsification time(EPT)were recorded. BCVA and CRT were observed postoperatively at 30d and 90d, counting of CEC was observed postoperatively at 90d. IOP was observed postoperatively at 1d and 7d.

RESULTS: The mean operation time for vitrectomy were 12.57±1.35min in 23G group and 17.30±1.19min in 20G group. The difference was statistically significant(t=-12.488, P<0.01). There were no statistical significances in operation time for membrane peeling, AVE and EPT between 23G and 20G groups(t=-0.68,-1.186,-0.737,P=0.500, 0.242,0.465). On 1d after surgery, IOP in 23G group was lower than that in 20G group, the difference was statistically significant(t=-2.345, P=0.024). The BCVA and CRT of the two groups both improved after operations. There were no statistically significant differences between two groups in terms of IOP, BCVA, and CRT(F=0.465, 1.895, 0.689; P=0.499, 0.176, 0.411). IOP, BCVA and CRT were significant statistical different in different time-point within each group(F=291.245, 103.06, 665.402, P<0.01). Different surgical methods of 23G and 20G had interactive effects on IOP with different time points(F=13.245, P<0.01), but different surgeries had no interactive effects on BCVA and CRT with different time points(F=1.212, 2.293; P=0.283, 0.129). The counting CEC in 23G group was more than that in 20G group postoperatively at 90d, the difference was statistically significant(t=2.049, P=0.048).

CONCLUSION: The 23G PPV combined with internal limiting membrane peeling, phacoemulsification, intraocular lens implantation for macular epiretinal membrane with cataract is effective. Compared with 20G PPV, 23G PPV has advantages in operation time for vitrectomy and counting CEC. But lower IOP is likely in 23G PPV on 1d after surgery