Donner Ruth, Laggner Maria, Aschauer Julia, Lammer Jan, Schmidinger Gerald
Department of Ophthalmology, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
Department of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
Ophthalmol Ther. 2022 Dec;11(6):2057-2066. doi: 10.1007/s40123-022-00564-1. Epub 2022 Sep 6.
This study aimed to test and evaluate modified corneal cross-linking (CXL) protocols regarding improved treatment effects on the peripheral cornea in terms of tissue stability and cellular response.
Peripheral CXL (pCXL) was performed within a ring of 9-11 mm of 36 human donor corneas with variations in applied energy (5.4, 7.2, and 10 J/cm) at 9 mW/cm irradiance. Each energy level was additionally modulated regarding the oxygen level surrounding the cornea during treatment (21%; 100%). Stress-strain tests with endpoints at 12% strain and collagenase A-assisted digestions to complete digestion were performed to evaluate the rigidity and resistance of treated and control tissue. Further, corneas were processed histologically via TUNEL assay and H&E staining to demonstrate the effects on stromal cells during treatment under varying CXL conditions.
Increases in energy dosage achieved significant increases in resistance to stress in all variations except when comparing protocols A and B under normoxic conditions. Supplemental oxygen significantly increased rigidity in protocols B (p < 0.01) and C (p = 0.018). Hyperoxic conditions significantly increased resistance to digestion in all protocols. The number of DNA strand breaks in TUNEL assay staining showed significant increases in all increases in energy as well as with oxygen supplementation.
Increases in energy and supplemental oxygen improved the effect of CXL, though endothelial safety could not be verified with confidence in high-fluence CXL with supplemental oxygen. Results suggest that CXL protocols using 7.2 J/cm with 100% O or 10 J/cm without supplemental oxygen prove most effective without anticipated risk of endothelial damage.
本研究旨在测试和评估改良的角膜交联（CXL）方案，该方案在组织稳定性和细胞反应方面对周边角膜具有更好的治疗效果。
对36个人类供体角膜9 - 11毫米环内进行周边角膜交联（pCXL），在9 mW/cm辐照下应用不同能量（5.4、7.2和10 J/cm）。每个能量水平在治疗期间还根据角膜周围的氧气水平进行调节（21%；100%）。进行应变为12%时的应力 - 应变测试以及胶原酶A辅助消化直至完全消化，以评估处理过的组织和对照组织的硬度和抗性。此外，通过TUNEL检测和苏木精 - 伊红（H&E）染色对角膜进行组织学处理，以证明在不同CXL条件下治疗期间对基质细胞的影响。
除了在常氧条件下比较方案A和B时，能量剂量的增加在所有变体中均显著提高了抗应力能力。补充氧气在方案B（p < 0.01）和方案C（p = 0.018）中显著提高了硬度。高氧条件在所有方案中均显著提高了抗消化能力。TUNEL检测染色中DNA链断裂的数量在所有能量增加以及补充氧气时均显著增加。
能量增加和补充氧气改善了CXL的效果，尽管在补充氧气的高能量CXL中无法确定内皮安全性。结果表明，使用7.2 J/cm且100%氧气或10 J/cm且不补充氧气的CXL方案被证明是最有效的，且没有预期的内皮损伤风险。
