IROC AG, Institute of Refractive and Ophthalmic Surgery, Stockerstrasse 37, Zurich, Switzerland.
Invest Ophthalmol Vis Sci. 2011 Nov 25;52(12):9048-52. doi: 10.1167/iovs.11-7818.
Ultraviolet (UV) corneal cross-linking is an accepted method for treating corneal ecstatic disorders. The authors evaluated whether a rapid treatment protocol (higher intensity and shorter irradiation time) could achieve the same increase in corneal stiffness as the currently used standard protocol.
Stress-strain measurements were performed on porcine corneal strips. The corneas (n = 72) were cut into three strips, each randomly receiving a different treatment: rapid (10 mW/cm(2), 9 minutes), standard (3 mW/cm(2), 30 minutes), or no (control, 0 mW/cm(2)) irradiation. After irradiation, the Young's modulus of each strip was determined. The results of the stress-strain measurements were analyzed statistically.
Statistical analysis showed that, after irradiation, the median value of Young's modulus from both active treatment groups (rapid, 3.83 N/mm(2); standard, 3.88 N/mm(2)) was significantly higher (P < 0.05) than that of the control group (2.91 N/mm(2)). Treatment increased Young's modulus by a factor of 1.3. However, there was no significant difference (P = 0.43) between the rapid and standard groups in the median of Young's modulus.
Rapid UV cross-linking treatment can be regarded as equivalent to the standard procedure in terms of increase in corneal stiffness. The new rapid protocol shortens the treatment duration by more than two thirds, from 30 to 9 minutes. The safety of the higher intensities must be addressed in further clinical studies.
紫外线（UV）角膜交联术是治疗角膜扩张症的一种公认方法。作者评估了快速治疗方案（更高的强度和更短的辐照时间）是否能达到与目前使用的标准方案相同的角膜硬度增加。
对猪眼角膜条进行应力-应变测量。将角膜（n=72）切成三条，每条随机接受不同的处理：快速（10 mW/cm²，9 分钟）、标准（3 mW/cm²，30 分钟）或无（对照，0 mW/cm²）照射。照射后，测定各条带的杨氏模量。对应力-应变测量结果进行统计学分析。
统计分析显示，照射后，两组主动治疗组（快速，3.83 N/mm²；标准，3.88 N/mm²）的杨氏模量中位数均显著高于对照组（2.91 N/mm²）（P <0.05）。治疗使杨氏模量增加了 1.3 倍。然而，快速和标准组之间的杨氏模量中位数没有显著差异（P=0.43）。
快速 UV 交联处理在增加角膜硬度方面可视为与标准程序等效。新的快速方案将治疗时间从 30 分钟缩短到 9 分钟，缩短了三分之二以上。更高强度的安全性必须在进一步的临床研究中解决。
