University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands.
Department of Plant Science and Environmental Health, the Weizmann Institute of Science, Rehovot, Israel.
Acta Ophthalmol. 2022 Jun;100(4):422-430. doi: 10.1111/aos.15021. Epub 2021 Sep 17.
To determine corneal cross-linking (CXL) efficacy and chromophore penetration after excimer laser-assisted patterned de-epithelialization.
Two-hundred-twenty porcine eyes were de-epithelialized ex vivo, either fully (mechanical; n = 88) or patterned (excimer laser; n = 132). Consecutively, corneas were impregnated with hypo- or hyperosmolar riboflavin (RF; n = 20, RF-D; n = 40, respectively) or water-soluble taurine (WST11; n = 40, and WST-D; n = 40, respectively), or kept unimpregnated (n = 80). Sixty corneas were subsequently irradiated, inducing CXL, with paired contralateral eyes serving as controls. Outcome measurements included strip extensiometry to assess CXL efficacy, and spectrophotometry and fluorescence microscopy to determine stromal chromophore penetration.
All tested chromophores induced significant CXL (p < 0.001), ranging from 7.6% to 14.6%, with similar stiffening for all formulations (p = 0.60) and both de-epithelialization methods (p = 0.56). Light transmittance was significantly lower (p < 0.001) after full compared with patterned de-epithelialization. Stromal chromophore penetration was comparable between fully and patterned de-epithelialized samples, with full penetration in RD and RF-D samples and penetration depths measuring 591.7 ± 42.8 µm and 592.9 ± 63.5 µm for WST11 (p = 0.963) and 504.2 ± 43.2 µm and 488.8 ± 93.1 µm for WST-D (p = 0.669), respectively.
Excimer laser-assisted patterned de-epithelialization allows for effective CXL. Stromal chromophore concentration is, however, reduced, which may have safety implications given the need for sufficient UVA attenuation in RF/UVA CXL. The different safety profile of near-infrared (NIR) may allow safe WST11/NIR CXL even with reduced stromal chromophore concentration values. In vivo studies are needed to evaluate the benefits and further assess safety of excimer laser-assisted patterned de-epithelialization for corneal CXL.
确定准分子激光辅助图案化去上皮化后角膜交联（CXL）的效果和发色团渗透。
220 只猪眼离体去上皮化，要么完全去上皮化（机械法；n=88），要么图案化去上皮化（准分子激光；n=132）。连续地，角膜用低渗或高渗核黄素（RF；n=20，RF-D；n=40）或水溶性牛磺酸（WST11；n=40，WST-D；n=40）渗透，或保持未渗透（n=80）。随后用配对的对侧眼作为对照，用 60 只眼角膜进行照射，诱导 CXL。结果测量包括条带延伸测量以评估 CXL 效果，以及分光光度法和荧光显微镜法以确定基质发色团渗透。
所有测试的发色团均诱导了显著的 CXL（p<0.001），范围为 7.6%至 14.6%，所有配方（p=0.60）和两种去上皮化方法（p=0.56）的硬度增加相似。与图案化去上皮化相比，完全去上皮化后的光透射率显著降低（p<0.001）。完全和图案化去上皮化样本之间的基质发色团渗透相当，在 RD 和 RF-D 样本中完全渗透，渗透深度分别为 591.7±42.8μm 和 592.9±63.5μm 用于 WST11（p=0.963）和 504.2±43.2μm 和 488.8±93.1μm 用于 WST-D（p=0.669）。
准分子激光辅助图案化去上皮化可实现有效的 CXL。然而，基质发色团浓度降低，这可能会对 RF/UVA-CXL 中需要足够的 UVA 衰减产生安全影响。近红外（NIR）的不同安全特性可能允许即使基质发色团浓度值降低，也可以安全地进行 WST11/NIR-CXL。需要进行体内研究来评估准分子激光辅助图案化去上皮化用于角膜 CXL 的益处，并进一步评估安全性。
