飞秒激光弧形角膜切开术对白内障合并角膜散光患者的矫正效果

目的　探讨飞秒激光弧形角膜切开术对白内障合并角膜散光患者的矫正效果。方法　选取33例（36眼）白内障合并角膜散光≥0.75 D的患者作为研究对象，均行飞秒激光弧形角膜切开术来矫正角膜散光。术前测患者裸眼远视力、最佳矫正远视力，用Pentacam三维眼前节分析系统测量角膜散光。行飞秒激光辅助的超声乳化白内障手术，术中弧形切口直径为9 mm，深度为90%。术后3个月时复查患者角膜散光、裸眼远视力、最佳矫正远视力，并用Alpins矢量分析法进行散光分析，主要观察以下矢量数据，即目标诱导散光向量、手术诱导散光向量、差异向量和矫正指数。结果　术前患者角膜散光为（1.16±0.35）D，术后3个月下降到（0.54±0.22）D，差异有统计学意义（P＜0.01）。术前裸眼远视力为0.81±0.42，术后3个月提高到0.26±0.24，差异有统计学意义（P＜0.01）。术前最佳矫正远视力为0.76±0.30，术后3个月提高到0.09±0.12，差异有统计学意义（P＜0.01）。对患者术前术后角膜散光的变化进行矢量分析显示，目标诱导散光向量为0.80～2.20（1.16±0.35）D，手术诱导散光向量为0.40～1.80（1.07±0.40）D，差异向量为0.20～1.00（0.54±0.22）D。矫正指数为0.89±0.35，理想值为1，提示总体为少许欠矫。大部分患眼（32眼）角度误差在15°范围内。成功指数平均值为0.47，提示还残留部分散光未得到矫正。通过公式计算可以得到散光矫正的成功率为53.0%。变平效果平均值为0.94，变平指数平均值为0.83。结论　飞秒激光弧形角膜切开术能有效矫正白内障合并角膜散光患者的角膜散光。

The effect of femtosecond-assisted arcuate keratotomy on cataract patients with corneal astigmatism

Objective　To evaluate the effectiveness of femtosecond-assisted arcuate keratotomy in correcting corneal astigmatism during cataract surgery.Methods　Thirty three patients (36 eyes) with cataracts and corneal astigmatism ≥0.75 D were selected as the subjects of this study，and all patients underwent femtosecond-assisted arcuate keratotomy to correct corneal astigmatism.The uncorrected distant visual acuity (UDVA) and the best corrected visual acuity (BCVA) were measured，and total corneal astigmatism was obtained by Pentacam before surgery.During femtosecond-assisted cataract surgery，the diameter and depth of the arc incisions were 9 mm and 90%.Three months after surgery，total corneal astigmatism，UDVA and BCVA were assessed，and the astigmatism analysis was analyzed by Alpins vector analysis，mainly involving following vector data，namely，the target induced astigmatism vector，the surgically induced astigmatism vector，the difference vector and correction index.Results　The total corneal astigmatism was (1.16±0.35)D before surgery，and was decreased to (0.54±0.22)D three months after surgery，and the difference was statistically significant (P<0.01).The UDVA was 0.81±0.42 before surgery，and was increased to 0.26±0.24 three months after surgery，and the difference was statistically significant (P<0.01).The BCVA was 0.76±0.30 before surgery，and was increased to 0.09±0.12 three months after surgery，and the difference was statistically significant (P<0.01).The changes in corneal astigmatism before and after operation were analyzed by vector analysis，and the target induced astigmatism vector was 0.80-2.20（1.16±0.35）D，the surgically induced astigmatism was 0.40-1.80（1.07±0.40）D，and the difference vector was 0.20-1.00（0.54±0.22）D.The correction index was 0.89±0.35，and the ideal value is 1，suggesting a little under correction.The angle of error of most eyes (32 eyes) was within 15°.The index of success was 0.47，indicating that the residual astigmatism was not corrected.The percentage success of astigmatism surgery was 53.0%.The average value of flattening effect was 0.94，and the average value of flattening index was 0.83.Conclusion　Femtosecond-assisted arcuate keratotomy can effectively reduce corneal astigmatism in cataract surgery.