摘要目的：对比观察27G与25G玻璃体切割手术（PPV）治疗特发性黄斑前膜（IMEM）的疗效。方法回顾性病例研究。临床检查确诊的IMEM患者38例38只眼纳入研究。患者获充分知情的情况下自愿选择行27G（A组）PPV或25G（B组）PPV，分别为18例18只眼、20例20只眼。行最佳矫正视力（BCVA）、眼压、裂隙灯显微镜、间接检眼镜、眼底彩色照相、光相干断层扫描（OCT）、角膜内皮细胞（CEC）计数检查。BCVA换算为最小分辨角对数（logMAR）视力进行记录。两组患眼平均logMAR BCVA、眼压、黄斑中心凹视网膜厚度（FMT）、CEC密度和六边形率比较，差异均无统计学意义（t=1.627、0.860、0.293、1.238、0.697，P＞0.05）。患眼均接受25G PPV或27G PPV，由同一位医师主刀完成。记录手术中玻璃体切割时间、剥膜时间。手术后1、7 d，1、3个月行BCVA、眼压检查；7 d，1、3个月行OCT检查；3个月行CEC计数检查。对比观察两组患眼logMAR BCVA、眼压、FMT、CEC计数变化以及视物变形改善情况。结果 A、B组患眼平均玻璃体切割时间分别为（6.7±2.8）、（10.5±3.3）min；两组患眼平均玻璃体切割时间比较，差异有统计学意义（t=3.084，P＜0.05）。平均剥膜时间分别为（10.2±5.2）、（11.0±5.9）min；两组患眼平均剥膜时间比较，差异无统计学意义（t=1.970，P=0.187）。手术后1、7 d，1、3个月，两组患眼logMAR BCVA比较，差异均无统计学意义（t=1.463、0.683、0.961、1.226，P=0.833、0.509、0.699、0.744）；平均眼压比较，差异均无统计学意义（t=1.314、1.262、0.699、1.116，P=0.763、0.721、0.534、0.712）。手术后1 d，A、B组患眼中眼压＜9 mmHg（1 mmHg=0.133 kPa）者为2、5只眼，分别占11.0%、25.0%。手术后7 d，1、3个月，A、B组患眼平均FMT值比较，差异均无统计学意义（t=1.257、1.368、1.437，P=0.735、0.745、0.869）。手术后3个月，A、B组患眼CEC密度比较，差异有统计学意义（t=2.276，P＜0.05）；CEC六边形率比较，差异无统计学意义（t=1.473，P=0.889）。结论27G与25G PPV治疗IMEM具有相似疗效；但27G较25G PPV可缩短玻璃体切割时间，降低手术后早期低眼压发生率，减小对CEC的损伤。

abstractsObjective To evaluate the effect of 27G pars plana vitrectomy (PPV) and 25G PPV on idiopathic epiretinal membrane (IMEM). Methods Thirty-eight eyes of 38 patients with IMEM were enrolled into this retrospective and comparative study. Eighteen eyes were treated with 27G PPV (group A), 20 eyes underwent 25G PPV (group B) voluntarily. The best corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp microscope, indirect ophthalmoscopy, fundus color photograph, ocular coherence tomography (OCT) and counting of corneal endothelial cells (CEC) were examined before the surgery. BCVA results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. There was no statistically significant difference between two groups in terms of BCVA, IOP, foveal macular thickness (FMT), the counting of CEC and CEC hexagon rate before the surgery (t=1.627, 0.860, 0.293, 1.238, 0.697;P>0.05). All operations&nbsp;were performed by the same doctor. Operation time for vitrectomy and peeling membrane was recorded. BCVA, IOP, OCT, FMT, counting of CEC and the improvement of metamorphopsia were observed on 1, 7 days and 1, 3 months after PPV. Results The mean operation time for vitrectomy in group A and B were (6.7±2.8), (10.5±3.3) min, respectively. The mean operation time for vitrectomy in group A was significantly longer than that in group B (t=3.084, P<0.05). The mean operation time for peeling membrane in group A and B were (10.2±5.2), (11.0±5.9) min, respectively. There was no statistically significant difference between two groups in terms of the time for peeling membrane (t=1.970, P=0.187). On 1, 7 days and 1, 3 months after PPV, the difference of BCVA (t=1.463, 0.683, 0.961, 1.226;P=0.833, 0.509, 0.699, 0.744) and IOP (t=1.314, 1.262, 0.699, 1.116;P=0.763, 0.721, 0.534, 0.712) between two groups were not statistically significant. On 1 day after PPV, there were 2 eyes and 5 eyes with<9 mmHg (1 mmHg=0.133 kPa) IOP in group A and B. On 7 days and 1, 3 months after PPV, the difference of FMT between two groups were not statistically significant (t=1.257, 1.368, 1.437;P=0.735, 0.745, 0.869). On 3 months after PPV, the difference of CEC between two groups were statistically significant (t=2.276, P<0.05);the difference of hexagon rate between two groups were not statistically significant (t=1.473, P=0.889). Conclusion The efficacy of 27G PPV for IMEM appears similar to 25G PPV. But 27G PPV has a shorter operating time for vitrectomy, a more stable IOP and a minimal damage to CEC.