Behrens A, Langenbucher A, Kus M M, Rummelt C, Seitz B
Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany.
Am J Ophthalmol. 2000 Jan;129(1):59-67. doi: 10.1016/s0002-9394(99)00269-x.
To compare flap dimensions, cut quality, and blade deterioration after reuse in an experimental setting using two current-generation microkeratomes for laser-assisted in situ keratomileusis.
Two pivoting-head principle microkeratomes, the Hansatome and the Supratome, were used to perform a corneal flap in 50 freshly enucleated pig cadaver eyes, with an intended thickness of 160 microm. Provided stainless steel blades were used from one to five times. Flap diameter was measured by planimetry and thickness calculated using ultrasonic pachymetry at three different locations. Scanning electron microscopy of stromal beds and blades' cutting edges were performed to assess the cut and blade deterioration after repeated use.
Mean flap central thickness (Hansatome/Supratome) was 151 microm (SD 18)/192 microm (SD 32). Progressive thinning/thickening of the flap was observed in the direction toward the hinge (P = .003/P = .021). Mean vertical flap diameters of 8.9 mm (SD 0.3)/8.0 mm (SD 0.4) differed significantly (P = .001). No correlation was found between thickness and diameter (r = 0.03, P = .935/r = 0.12, P = .603). At scanning electron microscopy, smooth cuts were observed with both keratomes using a new blade. Periodical chatter lines at keratectomy edge were present and were more pronounced after blade reuse. Cut quality, blade deterioration, and small tissue remnants on the blade surface were noted with repeated blade use, especially using the Supratome.
Local flap thickness and flap diameter variations are inherent to the instrument used. Comparable cut-surface quality can be obtained with new blades. Although cut and blade deterioration appears to be minor after two reuses, the presence of tissue remnants on the blade surface still limits its reuse.
在实验环境中，使用两种当代用于准分子原位角膜磨镶术的微型角膜刀，比较瓣片尺寸、切割质量以及重复使用后刀片的磨损情况。
使用两种旋转头原理的微型角膜刀，即汉沙刀（Hansatome）和超普刀（Supratome），在50只新鲜摘除的猪尸体眼睛上制作角膜瓣，预期厚度为160微米。所提供的不锈钢刀片使用1至5次。通过平面测量法测量瓣片直径，并在三个不同位置使用超声测厚仪计算厚度。对基质床和刀片切割边缘进行扫描电子显微镜检查，以评估重复使用后切割情况和刀片磨损。
瓣片中央平均厚度（汉沙刀/超普刀）为151微米（标准差18）/192微米（标准差32）。在朝向铰链的方向观察到瓣片逐渐变薄/变厚（P = 0.003/P = 0.021）。平均垂直瓣片直径分别为8.9毫米（标准差0.3）/8.0毫米（标准差0.4），差异有统计学意义（P = 0.001）。未发现厚度与直径之间存在相关性（r = 0.03，P = 0.935/r = 0.12，P = 0.603）。在扫描电子显微镜下，使用新刀片时两种微型角膜刀均观察到切割平滑。角膜切除术边缘出现周期性震颤线，刀片重复使用后更明显。随着刀片重复使用，尤其是使用超普刀时，注意到切割质量、刀片磨损以及刀片表面有小的组织残留。
局部瓣片厚度和瓣片直径变化是所用器械固有的。使用新刀片可获得相当的切割表面质量。尽管重复使用两次后切割和刀片磨损似乎较小，但刀片表面存在组织残留仍限制了其重复使用。
