准分子激光与角膜组织的相互作用及在屈光矫正中的应用

Excimer Laser-corneal Tissue Interactions and Applications

准分子激光在屈光手术中获得了迅速发展, 193 nm的准分子激光刻蚀角膜表面,改变角膜表面的光学结构从而矫正屈光不正,而且由于其微小的力学和热效应,不会损伤邻近组织。本文研究了激光和生物组织的相互作用,定性确定了光斑与角膜表面粗糙度关系,定量分析了193 nm准分子激光高斯光束的切削量与能量密度的关系。在此基础上,给出准分子激光应用到眼科治疗机中的原理图、屈光程度与激光消融量的关系和具体算法,最后通过PMMA板的实验验证,并已应用到临床,取得了良好的效果。

The excimer laser has shown a rapid development from the laboratory to its current clinical use for refractive surgery. Operating at 193 nanometers, the excimer laser is able to sculpt the corneal surface meticulously, altering the surface optical architecture to correct refractive errors. Such surgery is achieved with minimal mechanical and thermal effects upon the remaining corneal tissue. We studied laser and tissue interactions, investigated the effect of laser spot size and beam profile on the outcome of corneal surface smoothness and determined the relationship between the fluence of ArF excimer laser and the cornea ablation rate. The block diagram of ophthalmic excimer laser system and it's principle have been described. Finally, we tested ablations on polymethylmethacrylate (PMMA) and applied them to clinical operations with the satisfied results.