方法：对2010-03/2012-08在我院确诊为PDR Ⅳ期及以上的患者49例51眼作前瞻性临床对照研究，按随机、双盲的原则分为三组：第1组16例17眼，Avastin注射后4d行玻璃体切除术； 第2组15例16眼，Avastin注射后10d行玻璃体切除术； 第3组18例18眼为对照组，玻璃体切除术前未注射Avastin。详细记录术中手术时间、断膜出血、发生医源性视网膜裂孔、硅油使用及术后6mo视力情况。

结果：第1组(术前4d联合注药组)及第2组(术前10d联合注药组)与第3组(单纯玻切手术组)相比较，第1组及第2组术中手术时间明显缩短，术中断膜出血率、发生医源性视网膜裂孔率及硅油使用率明显低于第3组，且术后视力明显优于第3组。第1组与第2组相比在手术时间、术中断膜出血率、发生医源性视网膜裂孔率及硅油使用率及术后视力方面无明显统计学差异。

结论：PDR玻璃体切除术前注射Avastin有助于提高术中耐受性，且最大限度恢复患者有限视力； PDR玻璃体切除术前注射Avastin，较理想的注射时间为术前4d。

METHODS: We studied 49 patients(51 eyes)(from March 2010 to August 2012)with severe PDR. Sixteen cases(17 eyes)were treated with Avastin 4 days before PPV(group 1); 15 cases(16 eyes)were treated with Avastin 10 days before PPV(group 2); and 18 cases(18 eyes)underwent direct PPV(group 3). Surgical time, the condition of neovascular membranes, the number of iatrogenic retinal tear, and silicone oil utilization intra-operative, and vision after 6 months of surgery were recorded.

RESULTS: Compared to group 1(treated withAvastin, 4 days before PPV), group 2(treated with Avastin, 10 days before PPV)and group 3(simple vitrectomy surgery group), there were significantly difference. In group 1 and group 2, operative time was shortened, and interruption neovascular membranes bleeding rate, iatrogenic retinal tear rate and silicone oil utilization rate intra-operative were lower than the group 3, and the visual acuity was significantly better than the group 3. There was no statistically significant difference between group 1 and group 2 in surgical time, the condition of neovascular membranes, the number of iatrogenic retinal tear, and silicone oil utilization intra-operative, and vision 6 months after surgery.

CONCLUSION:Avastin administered prior to PPV was well tolerated, thus facilitating PPV, and to maximize the recovery of patients with limited vision. The ideal injection time of Avastin using for PPV in PDR is 4 days before PPV.