角膜交联术中紫外辐射安全性分析

Safety analysis of ultraviolet radiation in corneal collagen cross- linking

目的:利用人眼角膜简易模型研究和评价核黄素和UVA紫外光联合进行角膜交联术时对眼组织所产生的潜在光辐射伤害。方法:建立核黄素处理后的角膜的简化计算模型,根据国际非离子辐射防护委员会(ICNIRP)《眼科仪器光辐射对眼睛的照射指南调整》中的限值要求对设立的简化模型进行理论计算和推导,通过兔眼角膜实验数据分析UVA紫外光照射后对眼组织的辐射安全性。结果:根据所设立的简化计算模型得到核黄素处理后的角膜在365nm处的透过率限值26%,角膜交联手术中利用辐照强度3 mW/cm2(5.4mJ/cm2)UV激光对兔眼角膜照射,实际试验结果为14.46%±2.93%,小于该限值。结论:建立的简化模型在进行角膜交联手术中UVA激光安全性指标评价时不失为一种简单而有效的方法。所设立的简化计算模型,对于评价角膜交联手术中所使用的UV激光对眼组织辐射安全性来讲,具有一定的指导意义。

Establish a simplified calculation model of corneal to study and assess potential damage of optical radiation to ocular tissue during corneal collagen cross - linking by means of the riboflavin/UVA approach. Methods： Establish simplified cal- culation model of corneal after riboflavin processing, and then calculate and derived the model on the basis of statement from the International Commission on Non - Ionizing Radiation Protection （ICNIRP） ： Adjustment of guidelines for exposure of the eye to optical radiation from ocular instruments. Finally, through the experimental data for rabbit corneal, analyse the radiation safety for the ocular tissue after UVA radiation. Results： Under the simplified calculation model of corneal, the thresholds transmittance of 365nm is 26% for the corneal after riboflavin processing. After the currently used UVA radiant exposure of 5.4 mJ/cm^2 and the corresponding irradiance of 3 mW/cm^2 , the actual transmittance of rabbit corneal is below the known threshold, which is 14. 46% ± 2. 93%. Conclusion： Establishing the simplified calculation model of corneal is a simple and effective method for the safety assess of UVA radiation during corneal collagen cross - linking. And also provides guiding significance for the radiation safety for the ocular tissue after UVA radiation.