Elsheikh Ahmed, Alhasso Daad, Pye David
University of Dundee, UK.
J Biomech Eng. 2009 Nov;131(11):111013. doi: 10.1115/1.4000112.
With the world's aging population, it is expected that the number of people affected by glaucoma, the second most common cause of irreversible blindness, will increase considerably. Current knowledge on glaucoma progression relates elevation of the intraocular pressure (IOP) to optic nerve damage and hence visual impairment. For this reason, IOP measurement in tonometry has become an essential part of routine eye examinations needed for the diagnosis and management of the disease. The accuracy of the current reference standard in tonometry, the Goldmann applanation tonometer, is known to be affected by the natural variations in corneal thickness, curvature, and material properties. Earlier studies attempted to quantify these effects and produced correction factors that considered the variations in each one of these parameters separately, and no guidance was given as to how to combine the effects of variations in more than one parameter. The present research attempted to address this gap by conducting a multidimensional numerical study that considered variations in thickness, curvature, material properties, and IOP, and used the results to develop a single correction equation that considered these parameters simultaneously. The results of the analysis and the correction equation were validated successfully against the outcome of earlier clinical and mathematical studies on the effect of individual parameters, and the correction equation was presented in a simple form suitable for clinical application.
随着全球人口老龄化，预计受青光眼影响的人数将大幅增加，青光眼是不可逆失明的第二大常见病因。目前关于青光眼进展的认识是，眼压升高与视神经损伤以及由此导致的视力损害有关。因此，眼压测量已成为青光眼诊断和治疗所需常规眼部检查的重要组成部分。目前眼压测量的参考标准——Goldmann压平眼压计的准确性，已知会受到角膜厚度、曲率和材料特性自然变化的影响。早期研究试图量化这些影响，并分别针对这些参数中的每一个变化产生校正因子，但对于如何综合多个参数变化的影响并未给出指导。本研究试图通过进行一项多维数值研究来填补这一空白，该研究考虑了厚度、曲率、材料特性和眼压的变化，并利用研究结果开发了一个同时考虑这些参数的单一校正方程。分析结果和校正方程针对早期关于单个参数影响的临床和数学研究结果进行了成功验证，并且校正方程以适合临床应用的简单形式呈现。
