Femtosecond Laser Posterior Lamellar Keratoplasty

描述（由申请人提供）：内皮细胞层功能障碍导致角膜增厚，最终导致角膜透明度丧失。目前，穿透性角膜移植术被广泛用于替换病变的内皮。该手术的缺点包括高度角膜散光、角膜缝合并发症和易受伤口裂开影响的移植物-宿主连接弱。后板层角膜移植术仅替换患病的内皮和少量前后弹力层基质，可以避免这些问题，然而，使用传统手术器械进行手术的难度限制了这些手术的使用，只有极少数高度熟练的外科医生。新型飞秒激光手术技术能够实现高精度角膜切除，对邻近组织的附带损伤在临床上可忽略不计，并且不会在角膜前表面造成开放性切口或损伤。飞秒激光能量可以通过透明和半透明角膜传递，并聚焦在角膜前表面下的任何深度。通过沿角膜基质内的预定图案沿着扫描飞秒激光的焦点来实现组织切除。飞秒光致破裂产生一层微泡，将组织分离。这项技术现在已经被FDA批准用于切割角膜瓣和前角膜移植。 我们建议开发新的手术方法，使用飞秒激光在供体和宿主角膜中切割后角膜移植物来替换患病的内皮细胞层。新的宿主-供体组织接触几何形状，包括自锁伤口边缘，预计可促进伤口愈合。通过在利姆布斯处的小侧切口移除剥离的后角膜。通过相同的切口将供体移植物插入板层界面，并通过将空气注入前房中保持在适当位置。为了优化屈光结果和自锁或自密封伤口边缘，我们建议对术后角膜的生物力学进行建模，并通过体内动物实验证实这些结果。最后，我们建议在动物体内实验与非再生内皮研究的生理和生物力学的术后角膜移植几何形状和时间的函数。成功完成该项目将有助于理解飞秒激光后板层角膜移植术后的角膜生物力学和生理学。该项目引入了一种精确的显微外科技术，用于替换病变的内皮细胞，并可能加速恢复和改善视力。

DESCRIPTION (provided by applicant): Malfunction of the endothelial cell layer results in corneal thickening, and eventually the loss of corneal transparency. Currently, penetrating keratoplasty is widely used to replace the diseased endothelium. Disadvantages of the procedure include high corneal astigmatism, sundry suture complications and a weak graft-host junction that is susceptible to wound dehiscence. A posterior lamellar keratoplasty, which replaces only the diseased endothelium and a modicum of pre-Descemet's stroma can avert these problems, however, the difficulty of surgery using traditional surgical instruments limits the use of these procedures to a very few highly skilled surgeons. Novel femtosecond laser surgical technology is capable of creating high precision corneal resections with clinically negligible collateral damage to adjacent tissue and without opening cuts or damage at the anterior corneal surface. Femtosecond laser energy can be delivered through transparent and semitransparent cornea and focused at any depth beneath the corneal anterior surface. Tissue resection is achieved by scanning the focal spot of the femtosecond laser along a predetermined pattern inside the corneal stroma. A layer of microbubbles is created by femtosecond photodisruptions, which separates the tissue. The technology is now FDA cleared for cutting corneal flaps and anterior corneal grafts. We propose to develop new procedures to replace the diseased endothelial cell layer using femtosecond laser to cut posterior corneal grafts in both the donor and host corneas. Novel host-donor tissue contact geometries, including self-locking wound edges, are predicted to enhance wound healing. Diseased posterior cornea is removed through a small side incision at the limbus. The donor graft is inserted into the lamellar interface through the same incision and held in position with air injected into the anterior chamber. To optimize refractive outcomes and self-locking or self-sealing wound edges we propose to model the biomechanics of the postoperative cornea and confirm these results with in vivo animal experiments. Finally, we propose in vivo experiments in animals with non-regenerating endothelium to study the physiology and biomechanics of the postoperative corneas as a function of graft geometry and time. Successful completion of this project will contribute to the understanding of corneal biomechanics and physiology after femtosecond laser posterior lamellar keratoplasty. The project introduces a precision microsurgical technique for replacing diseased endothelium with potentially accelerated recovery and improved visual outcomes.