微创玻璃体手术后角膜屈光状态的观察

目的 比较23-G微创与常规20-G玻璃体手术后角膜屈光状态改变的差异.方法 前瞻性病例对照研究.选择同仁医院眼科中心2011年1月至2012年3月间行23-G微创玻璃体手术的患者44例(44眼)为23-G组,同期行20-G玻璃体手术的48例(48眼)患者为20-G组,分别于术前,术后2周、1个月、3个月行角膜地形图检查观察角膜屈光状态的改变.记录角膜地形图参数并进行比较分析.采用单因素方差分析,两样本t检验和x2检验.结果 ①术后3个月两组角膜地形图形态与术前比较差异无统计学意义(x2=5.26,P＞0.05).②20-G组内比较:术后1个月及3个月角膜曲率参数SimK2、Mean K低于术前(t=1.08、-3.67,P＜0.05),术后3d、2周及1个月角膜散光参数δSimK高于术前(t=0.53、0.9、0.56,P＜0.05),角膜表面规则参数术后3 d高于术前(t=0.74、0.63、1.08,P＜0.05).23-G组内比较:术后3d及术后2周角膜曲率参数SimK1高于术前(t=0.37、0.46,P＜0.05),角膜散光及角膜表面规则参数术后3d高于术前(P＜0.01).③与23-G组比较,20-G组术后1个月及3个月角膜曲率参数较低(P＜0.05),而散光参数较高(t=0.81、1.08,P＜0.05),角膜表面规则参数较高(P＜0.05).结论 20-G组患眼术后散光于术后1～3个月恢复至术前状态,但是术后3个月曲率依然低于术前;23-G组患眼术后角膜屈光状态于术后2周至1个月恢复至术前状态.与23-G组比较,20-G组术后曲率低而散光高.由此可见,23 -G玻璃体手术后切口愈合时间短,角膜屈光状态的改变小.

Corneal refractive change after microincision vitrectomy

Objective To observe corneal refractive change after 20-G and 23-G incision vitreoretinal surgery. Methods It was a prospective case-control study. Forty-four patients （44 eyes） who underwent 23-G vitreoretinal surgery were selected for a 23-G grouPsand 48 patients （48 eyes） who underwent 20-G vitreoretinal surgery during the same period were selected for the 20-G group. Corneal topography was performed before surgery and 3 days, 2 weeks, 1 month and 3 months postoperatively. The corneal topography parameters were recorded and the data were analyzed by ANOVA, independent samples t test and x2 test. Results （1）Corneal topography showed no significant differences in shape preoperatively compared to 3 months postoperatively 0（2=-5.26, P〉0.05）. （2）In the 20-G group： corneal curvature was reduced at 1 and 3 months postoperatively compared to preoperative parameters （t=1.08, -3.67, P〈0.05）. Corneal astigmatism 3 days, 2 weeks and 1 month postoperatively was higher than preoperative parameters （t=0.53, 0.9, 0.56, P〈0.05）. The regular parameters of the corneal surface were higher 3 days postoperatively compared to preoperative parameters （t=0.74, 0.63, 1.08, P〈0.05）. In the 23-G group： corneal curvature was higher 3 days and 2 weeks postoperatively compared to preoperative parameters （t=0.37, 0.46, P〈0.05）. Corneal astigmatism and the regular parameters of the corneal surface were higher 3 days postoperatively compared to preoperative parameters （P〈0.01）. （3）The 20-G group had lower corneal curvature parameters （P〈0.05）, higher astigmatism parameters （t=0.81, 1.08, P〈0.05）, and higher corneal surface regularity （P〈0.05） compared to the 23-G group. Conclusion Astigmatism recovered to preoperative levels in 1-3 months postoperatively, and corneal curvature was lower 3 months postoperatively compared to preoperative curvature. In the 23-G group, the corneal refractive status recovered to preoperative levels in from 2 weeks to 3 months postoperatively. Postoperative corneal curvature was lower and astigmatism was higher in the 20-G group compared to the 23-G group. Thus, 23-G vitreoretinal surgical wounds heal faster and result in smaller corneal refractive changes.