Krueger R R, Campos M, Wang X W, Lee M, McDonnell P J
Doheny Eye Institute, Los Angeles.
Arch Ophthalmol. 1993 Aug;111(8):1131-7. doi: 10.1001/archopht.1993.01090080127028.
To compare the effects of blowing dry (nitrogen or helium) and humidified gases over the corneal surface during photorefractive keratectomy.
Excimer laser myopic ablations were performed on porcine eyes (10 per group) using humidified and dry nitrogen and helium gas under ambient conditions. Surface smoothness was quantified with light and electron microscopy.
Corneas that were ablated using humidified gas were smooth and equivalent to those ablated under ambient conditions. Dry nitrogen and helium blowing resulted in increased surface irregularity evident on light and electron microscopy (P < .001). The pseudomembranes in the humidified gas and ambient air groups had fewer surface discontinuities than did those in the nonhumdified gas groups and appeared to have a thinner electron-dense surface layer.
The blowing of humidified gas during excimer laser corneal ablation produces a smoother surface than does the blowing of dry gas and is comparable to that produced under ambient (no blowing) conditions. Maintaining corneal moisture is important in photorefractive keratectomy. If blowing gas is necessary to remove debris from the surface, the gas should be humidified.
比较在准分子激光原位角膜磨镶术（PRK）过程中，向角膜表面吹拂干燥气体（氮气或氦气）与湿润气体的效果。
在环境条件下，使用湿润及干燥的氮气和氦气，对猪眼（每组10只）进行准分子激光近视消融。通过光学显微镜和电子显微镜对表面光滑度进行量化。
使用湿润气体消融的角膜表面光滑，与在环境条件下消融的角膜相当。吹拂干燥氮气和氦气导致光学显微镜和电子显微镜下表面不规则性增加（P <.001）。湿润气体组和环境空气组中的假膜表面连续性比未湿润气体组的少，并且似乎具有更薄的电子致密表面层。
在准分子激光角膜消融过程中吹拂湿润气体比吹拂干燥气体产生更光滑的表面，并且与在环境（不吹拂）条件下产生的表面相当。在准分子激光原位角膜磨镶术中保持角膜湿润很重要。如果需要吹拂气体以清除表面碎屑，则气体应进行湿润处理。
