Optimization Model for UV-Riboflavin Corneal Cross-linking
Optimization Model for UV-Riboflavin Corneal Cross-linking
复制标题
DOI：
10.1167/iovs.11-8059
复制
发表时间：
2012-02-01
影响因子：
4.4
通讯作者：
Seiler, Theo
中科院分区：
文献类型：
--
作者：
Schumacher, Silvia;Mrochen, Michael;Seiler, Theo
目的。开发核黄素紫外线-A 交联治疗的理论模型，该模型可以预测角膜组织硬度的增加，作为紫外线强度和核黄素浓度分布以及治疗时间的函数。方法。使用菲克第二扩散定律、朗伯-比尔光吸收定律和光聚合速率方程导出了计算角膜交联（聚合速率）增加的理论模型。在 43 组配对猪角膜条上以不同强度 (3-7 mW/cm(2)) 和不同核黄素浓度 (0.0%-0.5%) 进行应力应变实验，以确定 5% 应变下的杨氏模量。将杨氏模量增加的实验结果与模拟的聚合增加相关联，以确定模型与实验数据之间的关系。结果。该模型允许计算一维空间和时间强度和浓度分布。由强度、浓度分布和处理时间定义的总吸收辐射暴露与测量的刚度增加呈线性相关，从中可以确定 1.7 J/cm(2) 的阈值。根据模型计算，相对刚度增加显示与单位组织深度的理论聚合物增加呈线性相关。结论。该理论模型预测角膜交联导致的硬度增加的空间分布，因此可用于根据患者的角膜厚度和医疗适应症定制治疗。 （投资眼科可见科学。2012 年；53：762-769）DOI：10.1167/iovs.118059
PURPOSE. To develop a theoretical model for riboflavin ultraviolet-A cross-linking treatment that can predict the increase in stiffness of the corneal tissue as a function of the ultraviolet intensity and riboflavin concentration distribution, as well as the treatment time.METHODS. A theoretical model for calculating the increase in corneal cross-linking (polymerization rate) was derived using Fick's second law of diffusion, Lambert-Beer's law of light absorption, and a photopolymerization rate equation. Stress-strain experiments to determine Young's modulus at 5% strain were performed on 43 sets of paired porcine corneal strips at different intensities (3-7 mW/cm(2)) and different riboflavin concentrations (0.0%-0.5%). The experimental results for Young's modulus increase were correlated with the simulated polymerization increase to determine a relationship between the model and the experimental data.RESULTS. This model allows the calculation of the one-dimensional spatial and temporal intensity and concentration distribution. The total absorbed radiant exposure, defined by intensity, concentration distribution, and treatment time, shows a linear correlation with the measured stiffness increase from which a threshold value of 1.7 J/cm(2) can be determined. The relative stiffness increase shows a linear correlation with the theoretical polymer increase per depth of tissue, as calculated by the model.CONCLUSIONS. This theoretical model predicts the spatial distribution of increased stiffness by corneal cross-linking and, as such, can be used to customize treatment, according to the patient's corneal thickness and medical indication. (Invest Ophthalmol Vis Sci. 2012; 53: 762-769) DOI: 10.1167/iovs.118059