Hoffmann F, Schüler A, Wachtlin J
Augenklinik, Klinikum Steglitz, Freie Universität, Berlin, Germany.
Ger J Ophthalmol. 1993 Nov;2(6):395-9.
Apart from the original freezing technique, there are three non-freeze keratomileusis procedures, in which the cornea is first deformed before a tissue lens is severed from the side. Two measuring procedures were used to measure corneal lamellae separated from pig eyes by means of the microkeratome. The following parameters were determined: the size of the severed lamellae, given as the two diameters in the feed direction of the microkeratome and perpendicular to it, and the profiles of the axial sections of these lamellae as determined by means of the universal measuring microscope (UMM). Both measuring procedures had a precision of +/- 3 microns. The results obtained with different blade types were compared, and an optimized blade was developed. The corneal lamellae separated parallel to the surface using the optimized blade were of higher quality than those cut with the Barraquer microkeratome. The variation coefficient was 0.9% for the Berlin microkeratome and 6.0% for the Barraquer microkeratome. The profile studies demonstrated that rotationally symmetrical tissue sections can be obtained with the Berlin microkeratome. The lens-shaped tissue sections separated from pig cornea showed an undercorrection. Further studies are needed to determine whether a higher refraction precision can be achieved in lamellae cut from human donor cornea.
除了原始的冷冻技术外，还有三种非冷冻角膜磨镶术，即在从侧面切断组织透镜之前先使角膜变形。使用两种测量方法来测量通过微型角膜刀从猪眼中分离出的角膜薄片。确定了以下参数：切断薄片的尺寸，以微型角膜刀进给方向及其垂直方向上的两个直径表示，以及通过万能测量显微镜（UMM）确定的这些薄片轴向截面的轮廓。两种测量方法的精度均为±3微米。比较了使用不同刀片类型获得的结果，并开发了一种优化的刀片。使用优化刀片平行于表面分离的角膜薄片质量高于用巴拉奎尔微型角膜刀切割的薄片。柏林微型角膜刀的变异系数为0.9%，巴拉奎尔微型角膜刀的变异系数为6.0%。轮廓研究表明，使用柏林微型角膜刀可以获得旋转对称的组织切片。从猪角膜分离出的透镜状组织切片显示矫正不足。需要进一步研究以确定在从人类供体角膜切下的薄片中是否可以实现更高的屈光精度。
