基于膨胀实验和逆向建模技术评估戊二醛对兔角膜生物力学性能的影响

目的基于膨胀实验和逆向建模技术评估戊二醛对角膜生物力学性能的影响。方法实验研究。选取10只日本大耳白兔，处死摘取眼球。实验开始前测量角膜的厚度与直径。用随机数字表法选取每只白兔其中一眼进入实验组，另一眼进入对照组，分别浸入包含和不包含4%戊二醛的PBS磷酸盐缓冲液30 min。处理完毕后分离2组眼球制成附带巩膜环的完整角膜试件，固定于自制前房模拟装置，于角膜后表面施加液压，加压范围为2.1~45.0 mmHg，记录角膜前顶点的前突位移值；采用逆向建模技术计算角膜的应力、应变和正切模量值。数据采用配对t检验和配对Hotelling T2检验进行分析。结果戊二醛处理前实验组角膜的厚度、直径和对照组差异无统计学意义，戊二醛处理后角膜厚度下降约1/4。实验组测得的角膜正切模量值明显大于对照组；随着应力增加，相比于对照组，实验组角膜正切模量的增加比例逐渐减少（从199.5%下降到59.7%）。结论戊二醛处理后角膜正切模量明显增大，戊二醛促使胶原纤维间产生交联而增强角膜硬度。

Influence of glutaraldehyde on the biomechanical properties of the rabbit cornea using inflation testing and inverse modeling

Objective To determine the effect of glutaraldehyde on corneal biomechanical properties using inflation testing and inverse modeling. Methods Ten Japanese white rabbits were included in this experimental study. One eye was randomly selected from each rabbit and subjected to a PBS solution with 4% glutaraldehyde treatment for 30 minutes （experimental group）; the contralateral eye was suspended with a PBS solution without glutaraldehyde for the same amount of time （control group）. Specimens in both groups were loaded by cycles of pressure from 2.1 to 45.0 mmHg. And the experimentally obtained pressure-deformation data were used to derive the stress-strain behavior of each eye using an inverse modeling procedure. Corneal thickness and diameter were measured before the inflation test. The paired t test and paired Hotelling＇s T square test were used to analyze and compare the differences in corneal thickness, diameter, and tangent modulus between the two groups. Results Differences in the average corneal thickness and diameter in the experimental group before treatment with glutaraldehyde were not statistically significant from the control group. Glutaraldehyde significantly reduced corneal thickness. Corneal specimens treated with glutaraldehyde displayed significantly greater stiffness than those in the control group. With increments of stress, the growth ratio of the tangent modulus became increasingly lower （from 199.5% to 59.7% ）. Conclusion Glutaraldehyde treatment causes an increase in corneal material stiffness, while the material stiffening ratio decreased with an increase in stress.