Simulation of non-contact tonometer-Ocular response analyzer

Yıl 2016, Cilt: 4 Sayı: 2, 36 - 44, 01.03.2016

Mohammad Arsalan Khan

Öz

As per World Health Organization, Glaucoma is considered as the second leading cause of irreversible blindness worldwide. An accurate assessment of Intraocular Pressure (IOP) is crucial for diagnosis and management of a chronic eye disease called Glaucoma. The elevation of IOP in eye leads to optic nerve damage and hence causing visual impairment. Thus, IOP measurement in tonometry has become an essential part of routine eye examinations for the diagnosis, screening and managing response to treatment in patients.

Simultaneous explosion of ophthalmic knowledge and medical instrument, being made in the 19th century, has led to the invention of tonometers of varied designs and principles, and Non-Contact Tonometers (NCTs) are among them. Glodmann Applanation Tonometer (GAT) is considered the ‘gold standard’ in measuring IOP; however, IOP measurement using GAT is now known to be affected by various factors like corneal thickness, curvature and material properties as demonstrated by Khan [1]. Due to inaccuracies in measuring IOP by GAT, this ‘gold standard’ has been challenged. Therefore, the present research aims to develop a multi-parametric correction equation to determine the True Intraocular Pressure (IOPT) using Non-Contact Tonometer and the current article focuses on evaluating the influence of individual parameters on IOP by NCT.

Anahtar Kelimeler

Cornea, intraocular pressure, tonometry, glaucoma

Kaynakça

• M.A. Khan, Numerical study on human cornea and modified multiparametric correction equation for Goldmann applanation tonometer, J. Mech. Behav. Biomed. Mater. 30 (2014): 91-102.
• J. Morisson, (2003) Glaucoma - A clinical guide.
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• N. Ehlers, T. Bramsen, and S. Sperling, Applanation tonometry and central corneal thickness, Acta Ophthalmologica, 53 (1975), 34-43.
• M.M. Whitacre, and R. Stein, Sources of Error with use of Goldmann-type Tonometers, Survey of Ophthalmology, 38(1) (1993), 1-30.
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• A. Lam, D. Chen, R. Chiu, and W.S. Chui, Comparison of IOP Measurements between ORA and GAT in Normal Chinese, Optometry and Vision Science, 84(9) (2007), 909-914.