Selective Equatorial Sclera Crosslinking in the Orbit Using a Metal-Coated Polymer Waveguide
Selective Equatorial Sclera Crosslinking in the Orbit Using a Metal-Coated Polymer Waveguide
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DOI：
10.1167/iovs.19-26709
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发表时间：
2019-06-01
影响因子：
4.4
通讯作者：
Yun, Seok-Hyun
中科院分区：
文献类型：
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作者：
Kwok, Sheldon J. J.;Forward, Sarah;Yun, Seok-Hyun
目的.巩膜的光化学交联是一种新兴的技术，可以通过硬化巩膜组织来防止病理性近视中的眼睛过度伸长。为了克服在解剖学上受限的空间中均匀光传输的挑战，我们先前介绍了柔性聚合物波导的使用。我们目前展示了先进的波导，优化，以提供光选择性地在完整的眼眶赤道巩膜。我们的波导由聚二甲基硅氧烷包层和聚氨酯芯组成，耦合到光纤。沉积在波导的顶面和侧面上的反射银涂层防止光泄漏到非目标眶周组织。使用死后兔子来测试原位赤道巩膜交联的可行性。对离体兔眼进行张力测量，以确认生物力学硬化效应。金属涂覆的波导能够有效地将光递送到赤道巩膜的整个圆周，同时使到眶周组织的光泄漏最小。蓝光以22%的强度变化系数传递到完整的眼眶，导致核黄素荧光漂白45 +/- 11%。离体交联眼在5%应变下的杨氏模量增加了2倍（在25 J/cm（2）下增加了92% P < 0.05）。具有反射性、生物相容性表面的柔性聚合物波导可用于巩膜交联以实现靶向光递送。我们预计，我们所证明的程序将适用于活体动物模型中的巩膜交联，并可能适用于人体内。
PURPOSE. Photochemical crosslinking of the sclera is an emerging technique that may prevent excessive eye elongation in pathologic myopia by stiffening the scleral tissue. To overcome the challenge of uniform light delivery in an anatomically restricted space, we previously introduced the use of flexible polymer waveguides. We presently demonstrate advanced waveguides that are optimized to deliver light selectively to equatorial sclera in the intact orbit.METHODS. Our waveguides consist of a polydimethylsiloxane cladding and a polyurethane core, coupled to an optical fiber. A reflective silver coating deposited on the top and side surfaces of the waveguide prevents light leakage to nontarget, periorbital tissue. Postmortem rabbits were used to test the feasibility of in situ equatorial sclera crosslinking. Tensometry measurements were performed on ex vivo rabbit eyes to confirm a biomechanical stiffening effect.RESULTS. Metal-coated waveguides enabled efficient light delivery to the entire circumference of the equatorial sclera with minimal light leakage to the periorbital tissues. Blue light was delivered to the intact orbit with a coefficient of variation in intensity of 22%, resulting in a 45 +/- 11% bleaching of riboflavin fluorescence. A 2-fold increase in the Young's modulus at 5% strain (increase of 92% P < 0.05, at 25 J/cm(2)) was achieved for ex vivo crosslinked eyes.CONCLUSIONS. Flexible polymer waveguides with reflective, biocompatible surfaces are useful for sclera crosslinking to achieve targeted light delivery. We anticipate that our demonstrated procedure will be applicable to sclera crosslinking in live animal models and, potentially, humans in vivo.