The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province 325027 China ; The Institution of Ocular Biomechanics, Eye Hospital, Wenzhou Medical University, No. 270# Xueyuan West Road, Wenzhou City, Zhejiang Province 325027 China.
School of Engineering, University of Liverpool, Liverpool, L69 3GH UK.
Eye Vis (Lond). 2016 Mar 5;3:7. doi: 10.1186/s40662-016-0037-7. eCollection 2016.
To evaluate the symmetry of corneal biomechanical metrics, measured using an ocular response analyzer (ORA) and self-built corneal inflation test platform, in bilateral rabbit corneas and to investigate their relationship with physical intraocular pressure (IOPp).
Twenty fresh enucleated eyes from ten rabbits were used for ex vivo whole ocular globe inflation. IOP was increased from 7.5 to 37.5 mmHg with 7.5 mmHg steps and biomechanical metrics were acquired using the ORA. At least 3 examinations were performed at each pressure stage. Two biomechanical metrics, corneal hysteresis (CH) and corneal resistance factor (CRF) were recorded and analyzed as a function of IOPp. Corneal specimens were then excised from the intact ocular globe and tested under inflation conditions up to 45.7 mmHg posterior pressure. The experimental pressure-deformation data was analyzed using an inverse modeling procedure to derive the stress-strain behavior of the cornea.
A comparison of corneal shape parameters showed no statistically significant difference (P > 0.05) between bilateral eyes. Similarly, there were no statistically significant differences in values of CH, CRF and corneal stiffness (as measured by the tangent modulus, Et) between bilateral eyes (CH: F = 0.94, P = 0.54; CRF: F = 4.42, P = 0.35; Et: F = 3.15, P = 0.12) at different pressure levels. IOPp was highly correlated with CRF while the relationship with CH was less pronounced.
An obvious interocular symmetry in biomechanical metrics is found in this research. IOP has been shown to have important influences on the value of CRF provided by ORA.
评估使用眼反应分析仪（ORA）和自建角膜膨胀测试平台测量的双侧兔角膜的角膜生物力学指标的对称性，并研究其与物理眼内压（IOPp）的关系。
20 只新鲜兔眼球用于离体全眼球膨胀。IOP 从 7.5mmHg 增加到 37.5mmHg，步长为 7.5mmHg，使用 ORA 获得生物力学指标。在每个压力阶段至少进行 3 次检查。记录并分析了两个生物力学指标，角膜滞后（CH）和角膜阻力因子（CRF），并作为 IOPp 的函数进行分析。然后从完整眼球中切取角膜标本，并在高达 45.7mmHg 后向压力下进行膨胀条件下的测试。使用反模型程序分析实验压力变形数据，以推导出角膜的应力-应变行为。
双侧眼的角膜形状参数比较无统计学差异（P>0.05）。同样，双侧眼的 CH、CRF 和角膜硬度（由切线模量 Et 测量）值之间也没有统计学差异（CH：F=0.94，P=0.54；CRF：F=4.42，P=0.35；Et：F=3.15，P=0.12）。IOPp 与 CRF 高度相关，而与 CH 的关系不太明显。
本研究发现生物力学指标存在明显的眼间对称性。IOP 对 ORA 提供的 CRF 值有重要影响。
