角膜生物力学特性对散光性角膜切开术影响

Effect of corneal biomechanical parameters in astigmatic keratotomy

目的探讨屈光性晶状体置换联合散光性角膜切开术术后角膜生物力学特性的改变及其对手术效果的影响。方法收集角膜散光≥1．50D的患者，在屈光性晶状体置换术时联合行散光性角膜切开术。术前，术后1周、1、3、6个月用眼反应分析仪（Ocular response analyzer，Reichert，De．pew，NY）测量角膜阻力因子corneal resistance factor，CRF）、角膜滞后性（corneal hysteresis，CH）、Goldmann眼压（Goldmann correlated intraocular pressure，IOP）；用角膜地形图仪（Pentacamver．1．11；Oculus，Germany）观察角膜散光的变化。采用重复测量数据方差分析及Pearson相关分析进行统计分析。结果共23例（32只眼）。CRF、CH术后1周、1个月均低于术前水平（P〈0．05），术后3个月、6个月与术前比较差异均无统计学意义（P〉O．05）。IOP术后各时间点与术前比较差异均无统计学意义（P〉0．05）。散光矢量分解后术后J0的变化与CRF、CH负相关（P〈0．05），与10P无相关（P〉0．05）。J0，的变化与CRF、CH、IOP无相关（P〉0．05）。结论屈光性晶状体置换术联合散光性角膜切开术不会引起角膜生物力学特性的长期改变，CRF、CH对散光性角膜切开术手术效果产生一定的影响。

Objective To study the changes of comeal biomechanical parameters and the correlations between surgical induced corneal astigmatism and corneal biomechanical parameters in Astigmat- ic Keratotomy （AK）. Methods Patients with corneal astigmatism ≥1.50D underwent AK during refractive intraocular lens exchange. Corneal resistance factor （CRF）, Corneal hysteresis （CH） and Goldmann-correlated intraocular pressure （IOP） measurements were obtained with the Ocular Response Analyzer （ORA, Reichert., Depew, NY） before and l week, 1 month, 3 months and 6 months after surgery. Corneal astigmatism was also measured with Scheimpflug imaging （Pentacam ver. 1.11; Oculus, Germany）. Results Thirty-two eyes were included in this study. Both CRF and CH decreased briefly at 1 week and 1 month after AK surgery （both P 〈0.05） and recovered to the preoperative levels at 3 months and 6 months （both P 〉0.05）. There was no significant change in IOP （P 〉0.05）. The change of J0 （astigmatism vector analyzer） was negatively correlated with CRF and CH （P 〈0.05）, but was not correlated with IOP. The change of J45 was not correlated with CRF, CH and IOP （both P 〉0.05）. Conclusions AK surgery does not induce a significant change in corneal biomechanics, except for 1 week and 1 month postoperatively. CRF and CH may play some role in the change of astigmatism after AK.