Photochemical Kinetics of Corneal Cross-Linking with Riboflavin
Photochemical Kinetics of Corneal Cross-Linking with Riboflavin
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DOI：
10.1167/iovs.11-9385
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发表时间：
2012-04-01
影响因子：
4.4
通讯作者：
Muller, David
中科院分区：
文献类型：
--
作者：
Kamaev, Pavel;Friedman, Marc D.;Muller, David
目的。建立了核黄素（Rf）在离体猪角膜交联的光化学动力学模型，并通过不同能量输入条件下的氧浓度实验对模型进行了验证。建立了描述Rf角膜交联光化学动力学的理论模型。在蒸馏水中滴入Rf溶液后，将深度上皮化的猪角膜暴露在365nm紫外光（UV-A）下，不同的辐照度和温度。在UV-A照射下，用溶解氧光纤微传感器监测角膜中已知深度的氧浓度。用氧实验数据对模型进行了验证。根据已知的Rf和氧气进入角膜的化学反应和扩散速率，建立了与不同条件下UV-A照射时角膜耗氧量实验结果相一致的理论模型。角膜中的氧浓度受UV-A辐照度和温度的调节，并在UV-A照射开始时迅速下降。讨论了角膜与Rf交联的i型和ii型光化学机制的时间依赖性。使用化学动力学建模方法，作者开发了一个简单的模型，该模型与他们在角膜与Rf交联过程中角膜耗氧量的实验结果一致。认为主要的光化学动力学机制是Rf三联体与角膜蛋白活性基团的直接相互作用，主要通过自由基反应导致蛋白交联。（Invest Ophthalmol Vis Sci.2012;53:2360-2367） DOI:10.1167/iovs.11-9385
PURPOSE. To model the photochemical kinetics of corneal crosslinking with riboflavin (Rf) and confirm the model through measured oxygen concentration experiments under varying energy input conditions by UV-A irradiance and temperature modulation in ex vivo porcine cornea.METHODS. A theoretical model was developed to describe the corneal cross-linking photochemical kinetics of Rf. After instillation with drops of Rf solution in distilled water, deepithelialized porcine corneas were exposed to 365-nm ultraviolet light (UV-A) under varying irradiance and temperature. Oxygen concentration in the cornea at a known depth was monitored during UV-A illumination with a dissolved oxygen fiberoptic microsensor. Data from the oxygen experiments were used to confirm the model.RESULTS. On the basis of the known chemical reactions and diffusion rates of Rf and oxygen into the cornea, the authors developed a theoretical model consistent with corneal oxygen consumption experimental results during UV-A irradiation under different conditions. Oxygen concentration in the cornea is modulated by UV-A irradiance and temperature and quickly decreased at the beginning of UV-A exposure. The time-dependence of both Type-I and Type-II photochemical mechanisms in corneal cross-linking with Rf are discussed.CONCLUSIONS. Using a chemical kinetics modeling approach, the authors developed a simple model that is in agreement with their experimental results on oxygen consumption in the cornea during corneal cross-linking with Rf. It is suggested that the main photochemical kinetics mechanism is the direct interaction between Rf triplets and reactive groups of corneal proteins, which leads to the cross-linking of the proteins mainly through radical reactions. (Invest Ophthalmol Vis Sci.2012;53:2360-2367) DOI:10.1167/iovs.11-9385