Development and validation of a correction equation for Corvis tonometry
Development and validation of a correction equation for Corvis tonometry
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DOI：
10.1080/10255842.2015.1077515
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发表时间：
2016-07-03
影响因子：
1.6
通讯作者：
Elsheikh, Ahmed
中科院分区：
文献类型：
--
作者：
Joda, Akram Abdelazim;Shervin, Mir Mohi Sefat;Elsheikh, Ahmed
主要目标：本研究使用数值分析和验证临床数据，以开发一种方法来校正使用Corvis眼压计获得的眼内压（IOP）测量值，以获得中央角膜厚度（CCT）和年龄的影响。材料和方法：采用有限元法模拟眼压计气压对完整眼球地球仪的影响。分析考虑了IOP（10- 30 mmHg）、CCT（445-645 μ m）、R（7.2- 8.4 mm）、形状因子、P（0.6-1）和年龄（30- 90岁）变化较大的眼睛。在每种情况下，预测角膜变形并用于估计Corvis的IOP测量值（CVS-IOP）。对结果的分析得出了一种算法，该算法将真实IOP的估计值与CVS-IOP、CCT和年龄相关。所有其他参数对CVS-IOP的影响可忽略不计，因此从算法中省略。通过将该算法应用于涉及634只眼睛的临床数据集获得的校正CVS-IOP的预测值，评估其与角膜硬度参数、CCT和年龄的相关性。结果如下：对634例大型临床数据集内的CVS-IOP测量结果进行分析，结果显示与CCT（3.06 mmHg/100 μ m，r（2）=0.204）有较强的相关性，与年龄（0.24 mmHg/10年，r（2）=0.009）相关性较弱。将该算法应用于IOP测量，导致IOP估计值与CCT（0.04 mmHg/100 μ m，r（2）=0.005）和年龄（0.09 mmHg/10年，r（2）=0.002）的相关性降低。结论：本研究中开发的IOP校正过程成功降低了健康欧洲人群中IOP测量对角膜厚度和年龄的依赖性。
Primary objective: This study uses numerical analysis and validation against clinical data to develop a method to correct intraocular pressure (IOP) measurements obtained using the Corvis Tonometer for the effects of central corneal thickness (CCT), and age. Materials and Methods: Finite element analysis was conducted to simulate the effect of tonometric air pressure on the intact eye globe. The analyses considered eyes with wide variations in IOP (10-30mmHg), CCT (445-645 microns), R (7.2-8.4mm), shape factor, P (0.6-1) and age (30-90years). In each case, corneal deformation was predicted and used to estimate the IOP measurement by Corvis (CVS-IOP). Analysis of the results led to an algorithm relating estimates of true IOP as a function of CVS-IOP, CCT and age. All other parameters had negligible effect on CVS-IOP and have therefore been omitted from the algorithm. Predictions of corrected CVS-IOP, as obtained by applying the algorithm to a clinical data-set involving 634 eyes, were assessed for their association with the cornea stiffness parameters; CCT and age. Results: Analysis of CVS-IOP measurements within the 634-large clinical data-set showed strong correlation with CCT (3.06mmHg/100microns, r(2)=0.204) and weaker correlation with age (0.24mmHg/decade, r(2)=0.009). Applying the algorithm to IOP measurements resulted in IOP estimations that became less correlated with both CCT (0.04mmHg/100microns, r(2)=0.005) and age (0.09mmHg/decade, r(2)=0.002). Conclusions: The IOP correction process developed in this study was successful in reducing reliance of IOP measurements on both corneal thickness and age in a healthy European population.