Corneal wound healing: ocular optics after laser surgery

描述（由申请人提供）：屈光性角膜切削术（PRK）和激光辅助原位角膜磨镶术（LASIK）形式的激光屈光手术已成为矫正人类视力的重要手段。然而，即使屈光手术后愈合良好并达到适当的矫正，屈光手术后也经常出现并发症，降低了光学受益。在这些并发症中，有眼高阶光学像差的增加，特别是球面像差和彗差，以及原始低阶矫正随时间的回归。 虽然最近的研究已经揭示了角膜对屈光手术的愈合反应，但还没有了解这种反应如何影响角膜的形状和光波像差结构。这部分是由于缺乏合适的动物模型，其中联合收割机这样的调查。我们已经开发了一种实验范例，其中动物被训练成沿着眼科机器的光轴精确地和重复地注视。这使我们能够在相同的固定条件下进行光学相干断层扫描和波前传感，并具有与人类受试者相同的准确度和可重复性。这些仪器衍生的措施，然后可以与组织学研究的角膜生物学在同一只眼睛。使用该动物模型，我们建议通过测试以下假设来表征植入后高阶畸变和回归的细胞基质：（1）角膜伤口愈合，特别是角膜肌成纤维细胞，是激光屈光手术后高阶像差增加的主要原因，激光屈光手术后的屈光回退主要是由于激光切削局部角膜时引起的上皮增生 超过临界斜率。我们的目标是了解角膜伤口愈合过程中的细胞事件，它们改变角膜形状和改变眼睛的低阶和高阶光波像差特性的差异能力。这方面的知识是必不可少的预防和治疗策略的发展，旨在控制角膜的生物反应，以提高可靠性和减少并发症发生率后，激光屈光手术，它也将是至关重要的，我们成功地治疗高度像差的眼睛，如那些导致角膜移植和屈光手术。

DESCRIPTION (provided by applicant): Laser refractive surgery in the form of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) has become an important means of correcting vision in humans. However, even when it is followed by good healing and achieves suitable correction, refractive surgery is often followed by complications that decrease optical benefit. Among these complications is an increase in ocular higher order optical aberrations, especially spherical aberration and coma, and regression of the original lower order correction over time. While recent studies have shed considerable light on the healing response of the cornea to refractive surgery, there is no understanding yet about how this response affects the shape and optical wave aberration structure of the cornea. This is partly due to a lack of appropriate animal models in which to combine such investigations. We have developed an experimental paradigm in which animals are trained to accurately and repeatedly fixate along the optical axis of ophthalmic machines. This allows us to perform optical coherence tomography and wavefront sensing under the same fixation conditions and with the same degree of accuracy and repeatability as in human subjects. These instrument-derived measures can then be correlated with histological studies of corneal biology in the same eyes. Using this animal model, we propose to characterize the cellular substrates of higher order aberrations and regression following PRK by testing the following hypotheses: (1) that corneal wound healing and specifically corneal myofibroblasts, are responsible for a significant proportion of the increase in higher order aberrations after laser refractive surgery, and (2) that regression after laser refractive surgery is primarily due to epithelial hyperplasia induced when the laser ablation shape on the cornea locally exceeds a critical slope. Our goal is to understand cellular events during corneal wound healing in terms of their differential ability to alter corneal shape and change the lower and higher order optical wave aberration properties of the eye. This knowledge is essential for the development of both preventative and therapeutic strategies aimed at controlling the cornea's biological response in order to improve reliability and reduce complication rates after laser refractive surgery, it will also be critical to our successful treatment of highly aberrated eyes such as those resulting from corneal transplantation and refractive surgery.