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: 10222916
• 负责人: James V Jester
• 金额: $ 39.25万
• 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/10222916
• 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; 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; pain patient; 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.

项目概要/摘要 使用单光子 380 nm UVA 光来光激活核黄素 (Rf) 的胶原交联 (CXL) 已知可导致胶原蛋白硬度增加两倍，并使角膜变平 1-3 屈光度。虽然这些 效果已被证明对治疗圆锥角膜和矫正圆锥角膜具有显着的治疗效果 轻微的屈光不正，该手术有几个主要缺点，包括术后疼痛和 视力恢复延迟，细菌感染和角膜疤痕的风险增加。在我们最近 已完成 NEI 资助的研究项目，我们开发了双光子非线性光学 (NLO) CXL 方法 使用红外飞秒激光 (FS) 光，将 Rf 光激活限制在双光子焦体积内 物镜。该设备使用放大的 FS 激光器在低于 46.1 的温度下生成 760 nm、0.3 μJ 脉冲 mW 总功率（低于激光眼暴露的 ANSI 热极限），并且可以交联 4 毫米直径区域 不到4分钟，基质硬度显着增强1.6倍，角膜屈光度增加1至2倍 活兔压扁。作为该项目的一部分，我们还开发了一种新型的基于 FS 激光的角膜 上皮微加工方法通过上皮创建微通道 (MicroCh) 增强跨上皮 (TE) Rf 扩散。该项目的目标是检验以下假设：术后疼痛 视力恢复延迟是由于 UVA CXL 和 TE-NLO 造成的过度细胞损伤 CXL 显示细胞损伤明显减少，视力恢复更快。该假设将通过以下方式进行检验 目标 1. 通过确定以下因素的影响来优化 MicroCh TE Rf 基质渗透： 脉冲能量、密度和深度对 Rf 基质浓度和上皮/基质完整性的影响 其他使用离体兔眼的赋形 TE 方法。目标 2. 确定 TE Rf 穿透的影响 比较 MicroCh 与最佳赋形剂 Rf 方法对角膜上皮和基质完整性的影响 SA1 使用离体兔眼模型测量上皮/基质细胞死亡和诱导的炎症基因 使用和不使用 UVA 或 NLO CXL 时 3 小时和 24 小时的表达。目标 3. 确定 MicroCh 的效果 通过评估对活兔上皮完整性、角膜的影响，比较 Rf 传输和 UVA 与 NLO CXL 敏感性、间质炎症、伤口愈合和视力恢复。