Non-linear Optical Collagen Cross-linking (NLO CXL) for Treatment of Keratoconus

非线性光学胶原交联 (NLO CXL) 治疗圆锥角膜

• 批准号: 10391522
• 负责人: James V Jester
• 金额: $ 38.07万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10391522
• 关键词: Area; Bacterial Infections; Caliber; Cell Death; Cell Survival; Clinical Research; Collagen; Cornea; Coupled; Data; Debridement; Devices; Diffusion; Epithelial; Epithelial Cells; Excipients; Excision; Eye; Funding; Gene Expression; Goals; Hour; Inflammation; Inflammatory; Keratoconus; Lasers; Light; Measures; Minor; Modeling; Nerve; Operative Surgical Procedures; Optics; Oryctolagus cuniculus; Pain; Pathological Dilatation; Patients; Penetration; Photons; Physiologic pulse; Plasma; Postoperative Pain; Procedures; Publications; Recovery; Refractive Errors; Research; Research Project Grants; Riboflavin; Risk; Safety; Stromal Cells; Testing; Therapeutic; Ultraviolet Rays; Visual; adverse outcome; base; cell injury; corneal epithelium; corneal scar; crosslink; energy density; experience; individual patient; intraepithelial; ionization; lens; novel; photoactivation; repaired; side effect; two-photon; wound healing

Project Summary/Abstract Collagen crosslinking (CXL) using single photon, 380 nm, UVA light to photoactivate riboflavin (Rf) is known to induce a two-fold increase in collagen stiffness and 1-3 diopters of corneal flattening. While these effects have been shown to have significant therapeutic benefits for both treating Keratoconus and correcting minor refractive errors, there are several major drawbacks to this procedure, including post-operative pain and and delayed visual recovery with increased risk of bacterial infection and corneal scaring. In our recently completed, NEI funded research project we developed a two-photon, nonlinear optical (NLO) CXL approach using infrared femtosecond laser (FS) light that limits Rf photoactivation to the two-photon focal volume of an objective lens. This device uses an amplified FS laser to generate 760 nm, 0.3 μJ pulses at less than 46.1 mW total power (under the ANSI thermal limit for laser eye exposure), and can crosslink a 4 mm diameter area in less than 4 min, significantly enhance stromal stiffness 1.6 fold, and induce 1 to 2 diopters of corneal flattening in live rabbits. As part of this project, we have also developed a novel, FS laser based, corneal epithelial micromachining approach to create Microchannels (MicroCh) through the epithelium to greatly enhance transepithelial (TE) Rf diffusion. Goal of this project is to test the hypothesis that post-operative pain and delayed visual recovery is due to the excessive cellular damage caused by UVA CXL and that TE-NLO CXL shows significantly less cell damage with faster visual recovery. This hypothesis will be tested through the following specific aims: Aim 1. Optimize MicroCh TE Rf stromal penetration by determining the effects of pulse energy, density and depth on Rf stromal concentration and epithelial/stromal integrity as compared to other excipient TE approaches using ex vivo rabbit eyes. Aim 2. Determine the effects of TE Rf penetration on corneal epithelial and stromal integrity comparing MicroCh to optimal excipient Rf approaches identified in SA1 using an ex vivo rabbit eye model to measure epithelial/stromal cell death and induced inflammatory gene expression at 3 hours and 24 hours with and without UVA or NLO CXL. Aim 3. Determine the effects MicroCh Rf delivery and UVA versus NLO CXL in live rabbits by assessing the effects on epithelial integrity, corneal sensitivity, stromal inflammation, wound healing and visual recovery.

项目摘要/摘要 胶原蛋白交联（CXL）使用单个光子，380 nm，UVA光到光激活核黄素（RF）为 已知会诱导胶原蛋白刚度和1-3个角膜扁平蛋白的增加两倍。而这些 效果已被证明对治疗角膜结构和纠正具有显着的治疗益处 轻微的折射错误，此程序有几个主要缺点，包括术后疼痛和 并延迟视觉恢复，并增加了细菌感染和角膜恐惧的风险。在我们最近 完成的，NEI资助的研究项目我们开发了一个两光子的非线性光学（NLO）CXL方法 使用红外飞秒激光（FS）光，将RF光活化限制为两光焦点的焦点 客观镜头。该设备使用扩增的FS激光器在小于46.1的情况下生成760 nm，0.3μJ脉冲 MW总功率（在激光眼睛暴露的ANSI热极限下），并且可以交联4毫米直径的区域 在不到4分钟的时间内，显着增强基质刚度1.6倍，并诱导1至2个角膜 活着的兔子变平。作为该项目的一部分，我们还开发了一种小说，基于FS激光的角膜 上皮微加工方法，通过上皮创建微通道（微ch） 增强经式（TE）RF扩散。该项目的目标是检验术后疼痛的假设 延迟的视觉恢复是由于UVA CXL造成的过量细胞损伤和Te-Nlo造成的 CXL显示出明显较小的细胞损伤，并更快地视觉恢复。该假设将通过 以下具体目的：目标1。通过确定的影响 与RF基质浓度和上皮/基质完整性的脉冲能量，密度和深度相比 使用离体兔子眼睛的其他赋形剂方法。目标2。确定TE RF穿透的影响 在角膜上皮和基质完整性上，将微克与最佳赋形剂RF方法进行了比较 SA1使用离体兔眼模型测量上皮/基质细胞死亡并诱导炎症基因 使用和不带UVA或NLO CXL时3小时24小时的表达。目标3。确定效果微ch 通过评估对上皮完整性的影响 敏感性，基质感染，伤口愈合和视觉恢复。