角膜地形图引导下白内障手术切口构建的变异对角膜散光影响

目的 观察根据角膜地形图选择白内障手术切口位置及其构建变异,以进一步降低术前角膜散光.方法 对白内障患者123例(126只服),术前常规作角膜地形图检查.病人随机分成5组,A组、B组、E组为小切口手法组,A组和B组分别于上方和根据角膜地形图在强子午线方向行反眉形巩膜隧道切口;E组根据角膜地形图在强子午线方向行水平巩膜隧道切口;C组和D组为超声乳化组,分别于上方和根据角膜地形图在强子午线方向行透明角膜隧道切口;观察术后1d及7d后视力、角膜地形图等情况.结果 ①视力:术后7d,发现B组与E组患者差异有统计学意义,余各组间差异无统计学意义,组间裸眼视力≥1.0者差异亦无统计学意义.②术后散光轴向变化:A～D组变化不明显,E有12例散光轴向发生改变.③角膜散光:A组、B组散光变化较小,B组和E组术后7d较术前减少,差异有统计学意义;C组、D组术后1d角膜散光较大,7d后渐回复,但C组仍高于术前水平;A组与B组、C组与D组及A组与C组比较术后差异均无统计学意义;B组与D组术后1d差异有统计学意义,术后7d差异无统计学意义;B组与E组比较,术后1d差异无统计学意义,术后7d差异有统计学意义.结论 通过观察角膜地形图来选择白内障手术切口位置及其构建,可降低手术源性角膜散光或术前存在的角膜散光,明显改善术后早期视力.对进一步提高白内障术后的视觉质量具有临床指导意义.

The Effect of the Corneal Astigmatism in Changed Cataract Surgery Incision with the Corneal Topography

Objective To observe the effect of the corneal astigmatism in cataract surgery incision which selected according to corneal topography to further reduce the preoperative corneal astigmatism. Meth-ods Computer-assisted corneal topography was used to examine the 126 eyes of 123 patients preoperatively.The cases were divided into 5 groups randomly. Group A: Manual small incision cataract surgery (MSICS) Group: Superior anti-bow sclera tunnel incision was made on 22 eyes of Group A. Group B: MSICS Group: The anti-bow sclera tunnel incision was made on the steepest meridian according to the corneal topography ex-amined preoperatively on 28 eyes. Group C: Phacoemulsification Group: Superior clear corneal incision was made on 24 eyes of group C. Group D: Phacoemulsification Group: The clear corneal incision was made on the steepest meridian according to the corneal topography examined preoperatively on 26 eyes. Group E: MSICS Group: incision was made on the steepest meridian according to the corneal topography The straight sclera tun-nel examined preoperatively on 26 eyes. The corneal topography at 1 day and 7 days after surgery was ob-served and recorded except for visual acuity and so on. Results ①Visual acuity: The differences were not sta-tistically significant among these groups which Visual acuity was above 0.5 after 1 day and 7 days except the one between Group B and Group E after 7 days. ②Astigmatism axis conversion: The conversions were not sig-nificant from Group A to Group D. There were 12 cases changed in Group E. ③Corneal astigmatism: In Group A, the differences were not statistically significant among pre-operation, 1 day and 7 days. In Group B, the val-ues of corneal astigmatism in 1 day after surgery were a little more decreased than pre-existing ones, but were statistically significant 7 days later. The values of Group C and D were a little greater in 1 day after surgery and reduced 7 days later, however the values of Group C were higher. In group E, the differences between pre-oper-ation and post-operation were not statistically significant until 7 days later. Comparison of the corneal astigma-tism in Group A and Group B, Group C and Group D, Group A and Group C was not statistically significant.Group B and Group D had statistically significant difference in postoperative corneal astigmatism after 1d but opposite after 7d. On the contrary, Group B and Group E had no statistically significant difference in postopera-tive corneal astigmatism after 1d but opposite after 7d. Conclusions According to the corneal topography, it can reduce the surgical induced astigmatism or the pre-existing astigmatism and improve the visual acuity in short-term. There is an important clinical value to further improve the vision quality in postoperative cataract patients.