BACKGROUND & AIMS:
PURPOSE:Precision in corneal flap cutting is essential in LASIK surgery. Current mechanical microkeratomes have a very good performance record; however, in a few cases, complications can occur during the microkeratome pass and flap cut. Femtosecond lasers offer an alternative to the mechanical cut and can provide additional features regarding the flap morphology. In this study, we analyzed femtosecond laser flaps regarding their morphology, cut accuracy, and histopathology.
METHODS:Forty-five fresh porcine cadaveric eyes were prepared for femtosecond laser flap cutting with the Femtec femtosecond laser system (20/10 Perfect Vision, Heidelberg, Germany). The eyes were assigned to three different thickness groups, with 120-, 140-, or 180-microm cut depth, respectively. In addition, different flap diameters ranging from 8.0 to 9.5 mm and rim edge angulations between 60 degrees and 90 degrees were performed. After the cut, the eyes were examined under a microscope regarding accuracy and potential defects, and flap thickness and diameter were measured. In addition, flaps were prepared for further histopathologic examination.
RESULTS:All flap cuts were easily performed without any intraoperative complications. Flap thickness measurements revealed a median (in micrometers) of 110.5 (intended thickness 120), 142.5 (intended 140), and 180.0 (intended 180), respectively. The flap diameter for an intended size between 8.0 and 9.5 mm was within a range of +/-0.4 mm, the median at the maximum was 0.3 mm off. Histopathology revealed very low to almost no changes in the stromal structure of the cornea and correct hinge angulations.
CONCLUSIONS:LASIK flap cuts were easily performed without any complications. The accuracy and morphology were very precise and consistent. Histopathology revealed a smooth cut with hinge angulations, as expected.
背景与目标:
目的:角膜瓣切开的精确度在LASIK手术中至关重要。当前的机械微角膜刀具有非常好的性能记录;然而,在少数情况下,在微型角膜刀通过和皮瓣切割过程中可能会发生并发症。飞秒激光提供了机械切割的替代方法,并且可以提供有关皮瓣形态的其他功能。在这项研究中,我们分析了飞秒激光瓣的形态,切割精度和组织病理学。
方法:准备45只新鲜的猪尸体眼,用Femtec飞秒激光系统(20/10 Perfect Vision,德国海德堡)切割飞秒激光皮瓣。将眼睛分为三个不同的厚度组,分别具有120微米,140微米或180微米的切割深度。此外,还进行了从8.0到9.5毫米不等的襟翼直径和轮辋边缘成60度至90度的角度调整。切开后,在显微镜下检查眼睛的准确性和潜在缺陷,并测量皮瓣的厚度和直径。另外,准备皮瓣用于进一步的组织病理学检查。
结果:所有皮瓣切开都很容易,没有任何术中并发症。折翼厚度测量显示中位数(以微米为单位)分别为110.5(预期厚度120),142.5(预期厚度140)和180.0(预期厚度180)。预期尺寸在8.0到9.5毫米之间的襟翼直径在/-0.4毫米范围内,最大中值偏离0.3毫米。组织病理学显示,角膜基质结构的改变非常低甚至几乎没有改变,并且铰链角度正确。
结论:LASIK皮瓣切开很容易,没有任何并发症。准确性和形态非常精确且一致。如预期的那样,组织病理学显示平滑切开且铰链成角度。