Thompson K P, Barraquer E, Parel J M, Loertscher H, Pflugfelder S, Roussel T, Holland S, Hanna K
Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Florida 33101.
J Cataract Refract Surg. 1989 Jul;15(4):397-403. doi: 10.1016/s0886-3350(89)80057-4.
Experimental corneal trephination has been achieved with the 193 nm argon fluoride excimer and 2.9 microns hydrogen fluoride and Er:YAG laser systems. Compared with metal blades and other lasers, the 193 nm excimer laser creates the best quality corneal excision, but has a relatively slow etch rate through the stroma, and its use requires toxic gas. The mid-infrared laser systems trephine the cornea in less than 10 seconds, but cause a 10 microns to 15 microns zone of adjacent stromal damage and create wounds that are approximately 2.5 times larger than wounds made by metal scalpels. The wavelength and laser pulse duration influence the cutting characteristics of the laser. Optical delivery systems using an axicon lens, a rotating slit, and a computer controlled scanning optical system have been developed for penetrating keratoplasty. Selection of the optimal laser system for penetrating keratoplasty must await further experimental studies. Refinements of the laser cavity and delivery system are necessary before clinical studies can begin. A carefully controlled randomized clinical trial comparing laser trephination with conventional mechanical trephines will be necessary to determine the safety and efficacy of a laser trephination system.
已使用193纳米氟化氩准分子激光、2.9微米氟化氢激光和铒：钇铝石榴石激光系统实现了实验性角膜环切术。与金属刀片和其他激光相比，193纳米准分子激光能产生质量最佳的角膜切除术，但穿过基质的蚀刻速度相对较慢，且使用时需要有毒气体。中红外激光系统在不到10秒的时间内就能环切角膜，但会造成10微米至15微米的相邻基质损伤区域，且形成的伤口比金属手术刀造成的伤口大约大2.5倍。激光的波长和脉冲持续时间会影响其切割特性。已开发出使用轴锥透镜、旋转狭缝和计算机控制扫描光学系统的光学传输系统用于穿透性角膜移植术。为穿透性角膜移植术选择最佳激光系统必须等待进一步的实验研究。在开始临床研究之前，对激光腔和传输系统进行改进是必要的。有必要进行一项精心控制的随机临床试验，比较激光环切术与传统机械环切术，以确定激光环切系统的安全性和有效性。
