Renard G
Service d'ophtalmologie, Hotel-Dieu, Paris.
Bull Soc Belge Ophtalmol. 1997;266:23-5.
The studies of the effects of different lasers on the cornea have usually been done on animals. These studies show that ultra-violet lasers (Excimer 193 nm, 213 nm) have a pure photo-ablative effect, without distant lesions. The corneal endothelium is always intact as long as the laser beam is acting at a distance of more than 50 microns from the cells. The same findings after photo-ablation is the presence of a fibroblastic scar after epithelial healing. This scar correspond to the haze observed in clinical conditions. The infra-red lasers (Intrastomal YAG) produce an important thermal effect the corneal stroma and a destruction of the corneal endothelium if influence and frequency are increased. In conclusion, the lasers used in corneal surgery appear to be safe for the corneal structure but histological studies remain necessary for the new lasers in order to be certain of their safety.
关于不同激光对角膜影响的研究通常是在动物身上进行的。这些研究表明，紫外线激光（准分子激光193纳米、213纳米）具有纯粹的光消融作用，不会产生远处损伤。只要激光束与细胞的距离超过50微米，角膜内皮就始终保持完整。光消融后的相同发现是上皮愈合后出现纤维瘢痕。这种瘢痕与临床所见的 haze 相对应。红外激光（基质内YAG）会对角膜基质产生重要的热效应，并且如果强度和频率增加，会破坏角膜内皮。总之，用于角膜手术的激光对角膜结构似乎是安全的，但对于新型激光，仍有必要进行组织学研究以确定其安全性。
