CAJ | 학술논문

目的研究比较膨胀法加压角膜前、后表面所测角膜生物力学性能的差异.方法实验研究.8只日本大耳白兔纳入本研究.实验开始前测量角膜的厚度、直径和眼内压.每只白兔被随机选取一只眼膨胀法加压角膜的前表面(前表面加压眼组,n=8),另一只眼加压角膜的后表而(后表面加压眼组,n=8),加压范围为1.1～44.0 mmHg,记录角膜顶点前突位移值,然后采用板壳理论公式获得角膜的应力-应变关系、正切弹性模量和滞后量.两眼角膜厚度、直径、眼压、正切弹性模量和滞后量的比较均采用配对t检验进行分析.结果两眼之间角膜平均厚度、直径、眼压差异无统计学意义(厚度:t=-0.073,P＞0.05；直径:t=0.260,P＞0.05;眼压:t=- 1.033,P＞0.05).后表面加压眼组测得的角膜正切弹性模量值大于前表面加压眼组,且差异有统计学意义(t=6.664、6.681、6.931,P＜0.01)；前表面加压眼组的角膜滞后量明显大于后表面加压眼组,分别为2.50×104 MPa和1.94×10-4 MPa,差异有统计学意义(t=-2.891;P＜0.05).结论加压角膜后表面所测得的角膜硬度明显大于加压前表面.角膜作为非线性黏弹性组织,不仅在冠状面上表现出区域硬度的非对称性,而且在矢状面上也表现出硬度的非对称性.本实验研究结果对今后眼内压的校正具有一定参考价值.
목적 연구비교팽창법가압각막전、후표면소측각막생물역학성능적차이.방법 실험연구.8지일본대이백토납입본연구.실험개시전측량각막적후도、직경화안내압.매지백토피수궤선취일지안팽창법가압각막적전표면(전표면가압안조,n=8),령일지안가압각막적후표이(후표면가압안조,n=8),가압범위위1.1～44.0 mmHg,기록각막정점전돌위이치,연후채용판각이론공식획득각막적응력-응변관계、정절탄성모량화체후량.량안각막후도、직경、안압、정절탄성모량화체후량적비교균채용배대t검험진행분석.결과 량안지간각막평균후도、직경、안압차이무통계학의의(후도:t=-0.073,P＞0.05；직경:t=0.260,P＞0.05;안압:t=- 1.033,P＞0.05).후표면가압안조측득적각막정절탄성모량치대우전표면가압안조,차차이유통계학의의(t=6.664、6.681、6.931,P＜0.01)；전표면가압안조적각막체후량명현대우후표면가압안조,분별위2.50×104 MPa화1.94×10-4 MPa,차이유통계학의의(t=-2.891;P＜0.05).결론 가압각막후표면소측득적각막경도명현대우가압전표면.각막작위비선성점탄성조직,불부재관상면상표현출구역경도적비대칭성,이차재시상면상야표현출경도적비대칭성.본실험연구결과대금후안내압적교정구유일정삼고개치.
Objective To investigate and compare the corneal biomechanical properties obtained by inflating the corneal anterior surface and posterior surface.Methods In this experimental study.Eight Japanese white rabbits were included.One eye was randomly selected from each rabbit and was subjected to anterior pressure in an inflation test rig (anterior surface pressuring eyes group,n=8),and the contralateral eye was subjected to posterior pressure (posterior surface pressuring eyes group,n=8).The pressure range was 1.1-44.0 mmHg.Corneal apical displacement was recorded,then the shell theory was used to deduce the stress-strain relationship,tangent elastic modulus and hysteresis.Corneal thickness,diameter and intraocular pressure (IOP) were measured before the inflation test.A paired t test was used to analyze and compare corneal thickness,diameter,IOP,tangent elastic modulus and hysteresis values.Results Differences in the average corneal thickness,diameter and IOP were not statistically significant between the two groups (thickness:t=-0.073,P＞0.05;diameter:t=0.260,P＞0.05; IOP:t=-1.033,P＞0.05).Corneas tested under posterior pressure displayed significantly higher stiffness than those inflated by anterior pressure (t=6.664,6.681,6.931,P＜0.01).The hysteresis values of the anterior surface pressuring eyes group were significantly greater than those of the posterior surface pressuring eyes,the values were 2.50×10-4 MPa and 1.94×10-4 MPa,respectively.The difference was statistically significant (t=-2.891,P＜0.05).Conclusion Corneal specimens inflated posteriorly were significantly stiffer than those inflated anteriorly.As a nonlinear viscoelastic tissue,the cornea not only presented region-associated stiff asymmetry in the coronal plane,but also presented stiff asymmetry in the sagittal plane.The experimental results could have an reference value in correcting IOP readings in the future.