Fluid-Structure Interaction study of a vibration-based intraocular pressure measurements tonometer

Intraocular Pressure (IOP) measurement is vital in managing glaucoma progression. Controlling and managing IOP values in patients with glaucoma is very important to avoid blindness. In general, there are two types of IOP measurement devices (tonometers); contact and not contact. In contact tonometers, a probe is used to flatten the cornea, while in non-contact tonometers, air puff is used to deform the cornea. In both methods, IOP measurements can only be performed in hospitals and clinics by high skilled clinicians. Acoustic tonometry is a new non-contact, vibration-based and innovative device to measure IOP based on the natural frequency of the patient’s eye. Many investigators have studied acoustic tonometry and found that the natural frequency is correlated with the IOP.In this work, we conducted a parametric numerical study to investigate the effect of IOP and mechanical properties on the natural frequency of the eye. Fluid-Structure Interaction (FSI) models of human eyes were developed by varying the IOP and mechanical properties. For each case, the corneal displacement was extracted and used to compute the natural frequency using the Fast-Fourier transform (FFT). The study found that vibration-based tonometers can be an excellent alternative tonometer to measure IOP.