Department of Ophthalmology, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
Research & Development Department, Opto Eletronica S.A., São Paulo, SP, Brazil.
Arq Bras Oftalmol. 2024 Mar 4;87(2):e20220273. doi: 10.5935/0004-2749.2022-0273. eCollection 2024.
To determine the absorbance coefficient of the thin porcine cornea to ultraviolet-A radiation (365 nm) submitted for crosslinking.
This in vitro, benchtop experiment using cadaver tissue study analyzed 12 porcine corneal lamellas, which were obtained using a microkeratome after mechanical de-epithelization and separated into three thickness groups: 180, 300, and 360 μm. The corneal thickness values were measured by anterior-segment optical coherence tomography. All lamellas had ultraviolet-A (365 nm) absorbance measured with a 96-well plate spectrophotometer using an ultraviolet transparent microplate before riboflavin instillation and preand post-crosslinking according to the Dresden protocol.
The ultraviolet absorbance profiles of the 180, 300, and 360 μm groups were obtained as α-coefficients of 12.85, 76.55, and 120.27, respectively. A theoretical formula was calculated though a statistical analysis that demonstrated the correlation between stromal lamellar thickness and ultraviolet absorbance.
Corneal thickness and ultraviolet-A spectral absorbance of corneal lamellas showed linear correlation. These findings can potentially contribute to the optimization of ultraviolet-A application during crosslinking, making the treatment of corneas with thickness <400 μm safe and personalized energy delivery for each corneal thickness.
确定用于交联的薄猪眼角膜对紫外线-A 辐射（365nm）的吸收系数。
本体外台式实验使用尸体组织研究分析了 12 个猪眼角膜瓣，这些瓣在机械去上皮化后使用微型角膜刀获得，并分为 3 个厚度组：180、300 和 360μm。角膜厚度值通过眼前节光学相干断层扫描测量。所有瓣均使用 96 孔板分光光度计测量紫外线-A（365nm）吸收，在滴入核黄素之前和根据德累斯顿方案进行交联之前使用紫外线透明微孔板进行测量。
获得了 180、300 和 360μm 组的紫外线吸收曲线，其α系数分别为 12.85、76.55 和 120.27。通过统计分析计算出一个理论公式，表明基质瓣厚度与紫外线吸收之间存在相关性。
角膜瓣的角膜厚度和紫外线-A 光谱吸收呈线性相关。这些发现可能有助于优化交联过程中的紫外线-A 应用，使厚度<400μm 的角膜的治疗安全，并为每个角膜厚度个性化地提供能量传递。
