飞秒激光辅助的兔眼角膜深板层切削的实验研究

Experimental Study of Femtosecond Laser-Assisted Deep Lamellar Cut in Rabbit Corneas

为了探讨飞秒激光在兔眼角膜上行深板层切削的可行性,获得深板层切削的较适参数,并了解在水肿角膜上行深板层切削的准确性,将兔眼置于由同心圆扫描程序控制的三维平台上,将不同能量的飞秒激光(800 nm/50 fs)精确定位于角膜深板层,伴随平台移动激光便在角膜深板层切削。利用光学显微镜和扫描电镜(SEM)观察激光作用后角膜的形态学变化,并同徒手器械分离的板层角膜对比。当平台移动速度为200μm/s,激光能量为4.4μJ时切削表面比较平滑;当速度为300μm/s,能量为6.4μJ时切削表面较为平滑。激光组切削层面的光滑程度优于徒手器械分离组;当平台移动速度为200μm/s,能量为6.4μJ时飞秒激光同样可以完成在水肿角膜的400μm深度的聚焦切削,且切削表面较为光滑。

The purpose is to assess the the feasibility of femtosecond laser application in deep lamellar cut in rabbit corneas, search for the suitable parameter, and to evaluate the laser＇s effectiveness through edema corneas. The sample was put on a three-axis translation stage which was under the control of concentrically ringed program, femtosecond laser （800 nm/50 fs） with different pulse energies was applied to focus on the rabbit corneas. The laser focused on the deep lamellar and produced dissection through the corneas along with the movement of the stage. After the lamellar interface cut, the corneal cut surface was examined by light microscopy and scanning electron microscopy （SEM）. The corneas operated by using surgical instruments were used as controls. With the pulse energy of 4.4 μJ and the translation stage speed of 200 μm/s, the laser produced an effective and smooth dissection. While with the energy of 6.4 μJ at the speed of 300 μm/s, the laser made an effective and smooth dissection. Compared with the controls , the experimental groups were better. The laser could also successfully created a smooth cut at the deepness of 400 μm on the edema cornea at the speed of 200 μm/s and the energy of 6.4 μJ.