Femtosecond Laser Posterior Lamellar Keratoplasty

飞秒激光后板层角膜移植术

• 批准号: 6611694
• 负责人: TIBOR JUHASZ
• 金额: $ 38.04万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6611694
• 关键词: Macaca fascicularis; biomechanics; biotechnology; cornea opacity; corneal endothelium; corneal stroma; eye laser surgery; high throughput technology; laboratory rabbit; postoperative state; refractive keratoplasty; scanning transmission electron microscopy; technology /technique development; transmission electron microscopy; wound healing

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.

描述(申请人提供)：内皮细胞层的故障导致角膜增厚，最终导致角膜透明度的丧失。目前，穿透性角膜移植被广泛用于替代病变的内皮细胞。该手术的缺点包括角膜高度散光，各种缝合并发症，以及移植物-宿主连接薄弱，容易发生伤口裂开。后板层角膜移植，只替换病变的内皮和少量的前Descemet基质可以避免这些问题，然而，使用传统手术器械的手术难度限制了这些手术仅限于极少数高技能的外科医生。新的飞秒激光手术技术能够实现高精度的角膜切除，对邻近组织的侧枝损伤临床上可以忽略不计，并且不会在角膜前表面切开或造成损伤。飞秒激光能量可以通过透明和半透明的角膜传递，并聚焦在角膜前表面以下的任何深度。组织切除是通过沿着角膜基质内预定的图案扫描飞秒激光的焦点来实现的。飞秒光破坏产生了一层微泡，将组织分开。该技术现已获得FDA批准，可用于切割角膜瓣和角膜前部移植物。 我们建议开发新的程序来替换病变的内皮细胞层，使用飞秒激光切割供体和宿主角膜的后部角膜移植物。新的宿主-供体组织接触几何结构，包括自锁伤口边缘，预计将促进伤口愈合。病变的后部角膜通过在角膜缘的一个小的侧切口处被取出。供体移植物通过同一切口植入板层界面，并在前房内注气固定到位。为了优化屈光效果和自锁或自封闭的伤口边缘，我们建议建立术后角膜的生物力学模型，并用活体动物实验证实这些结果。最后，我们建议在动物体内进行非再生内皮细胞实验，以研究术后角膜的生理和生物力学随移植几何形状和时间的变化。该项目的成功完成将有助于了解飞秒激光后板层角膜移植后的角膜生物力学和生理学。该项目引入了一种精密的显微外科技术，用于替换病变的内皮细胞，具有潜在的加速恢复和改善视力的效果。