Shah Sunil, Laiquzzaman Mohammad, Yeung Ian, Pan Xueliang, Roberts Cynthia
Heart of England Foundation Trust, Solihull, UK; Ophthalmic Research Group, Aston University, Birmingham, UK.
Cont Lens Anterior Eye. 2009 Jun;32(3):123-8. doi: 10.1016/j.clae.2009.02.005. Epub 2009 Mar 24.
To compare corneal biomechanical parameters and two measures of intraocular pressure (IOP) in eyes before and after excimer laser refractive surgery, with the Ocular Response Analyser (ORA).
Eighty normal eyes of 41 patients undergoing excimer laser refractive surgery in Birmingham, U.K. were recruited into three groups: Laser Assisted-Epithelial Keratomileusis (LASEK) (Myopes), Laser Assisted in Situ Keratomileusis (LASIK) (myopes) and LASIK (hyperopes). The preop and 3 months postop Goldmann correlated IOP (IOPg), corneal compensated IOP (IOPcc), corneal hysteresis (CH), and corneal resistance factor (CRF) were measured by the ORA. Central corneal thickness (CCT) was measured using ultrasonic pachymeter. The differences of the changes in IOPg, IOPcc, CH, CRF and CCT between the three groups were estimated. A General Linear Model was selected to investigate the influence of gender, age, initial conditions (CH, CRF, CCT, IOPcc and IOPg) and changes in CCT on the measured IOP.
The differences between the mean IOPg, CH and CRF after refractive surgery were statistically significant for all three groups. The hyperopic LASIK group had a significantly smaller change compared to the other groups (which had no statistical significance). The preop IOPg, preop CH and gender were significant predictors of the changes in measured pressure and biomechanical parameters after surgery in the myopic groups only.
CH and CRF were found to decrease after both myopic and hyperopic refractive surgery. CH and CRF measurement may prove important tools to clarify the role of corneal biomechanics for refractive surgery.
使用眼反应分析仪（ORA）比较准分子激光屈光手术前后眼睛的角膜生物力学参数和两种眼压（IOP）测量值。
招募了英国伯明翰市41例接受准分子激光屈光手术的患者的80只正常眼睛，分为三组：激光辅助上皮下角膜磨镶术（LASEK）（近视患者）、激光原位角膜磨镶术（LASIK）（近视患者）和LASIK（远视患者）。通过ORA测量术前和术后3个月的Goldmann相关眼压（IOPg）、角膜补偿眼压（IOPcc）、角膜滞后（CH）和角膜阻力因子（CRF）。使用超声角膜测厚仪测量中央角膜厚度（CCT）。估计三组之间IOPg、IOPcc、CH、CRF和CCT变化的差异。选择一般线性模型来研究性别、年龄、初始条件（CH、CRF、CCT、IOPcc和IOPg）以及CCT变化对测量眼压的影响。
屈光手术后，所有三组的平均IOPg、CH和CRF之间的差异具有统计学意义。远视LASIK组与其他组相比变化明显较小（无统计学意义）。仅在近视组中，术前IOPg、术前CH和性别是术后测量眼压和生物力学参数变化的重要预测因素。
近视和远视屈光手术后CH和CRF均降低。CH和CRF测量可能是阐明角膜生物力学在屈光手术中作用的重要工具。
