Hofmann R F, Bechara S J
Department of Ophthalmology, Emory University School of Medicine, Atlanta, Ga.
Refract Corneal Surg. 1992 Sep-Oct;8(5):348-54.
Microkeratome designs for lamellar refractive surgery have changed significantly in recent years. Three microkeratome systems (Automatic Corneal Shaper (Steinway Instrument Company, Inc, San Diego, Calif), Draeger Lamellar Keratome (Storz Instrument GmbH, Heidelberg, Germany), and Microprecision test model (Microprecision Instrument Company, Inc, Phoenix, Ariz) were subjected to a concurrent and independent evaluation.
Three types of keratectomies (primary superficial stromal, secondary intrastromal, and primary deep stromal) were performed under identical conditions in human cadaver eyes. The resected discs and the beds were observed for uniformity, accuracy, centering, and smoothness. Scanning electron microscopy of the corneal beds and cutting blades was done.
The three systems produced irregular surfaces with chatter lines that appeared least rough with the Draeger rotating machine. The average primary and secondary section diameters were undersized by 10% in all three systems. The average primary keratectomy thickness was more accurate with Steinway, but the variability was over 20 microns in all three systems. Regarding the average secondary keratectomy thickness, Steinway tended to cut thicker, whereas Draeger and Microprecision tended to cut thinner than attempted. The Draeger blade presented the smoothest edge.
All three systems need substantial improvements to produce more accurate, reproducible, and smooth resections. More reliable methods to accurately measure the thickness of the resected cornea should be developed.
近年来，用于板层屈光手术的微型角膜刀设计发生了显著变化。对三种微型角膜刀系统（自动角膜成形仪（Steinway仪器公司，加利福尼亚州圣地亚哥）、Draeger板层角膜刀（德国海德堡的Storz仪器有限公司）和Microprecision测试模型（Microprecision仪器公司，亚利桑那州凤凰城）进行了同步独立评估。
在人类尸体眼的相同条件下进行三种类型的角膜切除术（原发性浅层基质、继发性基质内和原发性深层基质）。观察切除的角膜片和床面的均匀性、准确性、对中性和平滑度。对角膜床和切割刀片进行扫描电子显微镜检查。
这三种系统产生的表面不规则，有震颤线，Draeger旋转机器产生的表面粗糙度最小。在所有三种系统中，原发性和继发性切片的平均直径都比预期小10%。Steinway的原发性角膜切除术平均厚度更准确，但在所有三种系统中，其变异性超过20微米。关于继发性角膜切除术的平均厚度，Steinway倾向于切得更厚，而Draeger和Microprecision倾向于切得比预期更薄。Draeger刀片的边缘最光滑。
所有三种系统都需要大幅改进，以实现更准确、可重复和平滑的切除。应开发更可靠的方法来准确测量切除角膜的厚度。
