Stonecipher K G, Parmley V C, Rowsey J J, Fowler W C, Nguyen H, Terry M
Dean A. McGee Eye Institute, Oklahoma City, Okla.
J Refract Corneal Surg. 1994 Jan-Feb;10(1):49-55.
Instrumentation for performing a uniform lamellar keratoplasty has been undergoing various stages of refinement. Reliable reproduction and uniform thickness and diameter of lamellar resections is required before lamellar refractive keratoplasty can be considered safe and effective.
The authors used the Draeger rotary microkeratome with mechanical blade advance for lamellar dissections in 61 human cadaver eyes prepared by injecting Swinger-Kornmehl (SK) solution into the anterior chamber to a pressure of 35 to 40 mm Hg and by soaking for 30 minutes in SK solution. Spacer sizes of 0.25 to 0.40 units were utilized using an anterior lamellar disc diameter estimate between 8.0 and 8.5 mm and a stromal lamellar disc diameter estimate between 5.5 and 6.5 mm. Preoperative pachometry, anterior and stromal lamellar disc thicknesses, and anterior and stromal lamellar disc diameters were measured.
The Draeger unit created anterior lamellar thickness between 100 and 268 microns. Stromal lamellar disc thicknesses were consistently between 90 and 161 microns. The continuous, unidirectional, rotary blade and the uniform mechanical advance of the instrument produced a generally uniform bed as evaluated by scanning electron microscopy, although undulations were still present.
The Draeger microkeratome produced regular lamellar dissections; however, predictability of the thickness of the lenticules varied 10% to 20%, and of the diameter, 1.5% to 15%. Predictability improved with experience. This variability may reduce predictability of refractive outcome.
用于进行均匀板层角膜移植术的器械一直在经历不同阶段的改进。在板层屈光性角膜移植术被认为安全有效之前，需要可靠地再现以及板层切除厚度和直径的均匀性。
作者使用德格（Draeger）旋转微型角膜刀，通过向前房注入斯温格 - 科恩梅尔（SK）溶液至压力为35至40毫米汞柱并在SK溶液中浸泡30分钟来制备61只人尸体眼，然后进行板层剥离。使用前板层盘直径估计在8.0至8.5毫米之间以及基质板层盘直径估计在5.5至6.5毫米之间，采用0.25至0.40单位的间隔器尺寸。测量术前角膜厚度、前板层盘和基质板层盘的厚度以及前板层盘和基质板层盘的直径。
德格设备制作的前板层厚度在100至268微米之间。基质板层盘厚度始终在90至161微米之间。尽管仍存在波动，但通过扫描电子显微镜评估，连续、单向的旋转刀片和器械均匀的机械推进产生了大致均匀的床面。
德格微型角膜刀产生了规则的板层剥离；然而，透镜厚度的可预测性变化为10%至20%，直径的可预测性变化为1.5%至15%。可预测性随着经验的增加而提高。这种变异性可能会降低屈光结果的可预测性。
