Detection of intraocular pressure change in a human eye model using sonoelastic Doppler ultrasound

Sonoelasticity is proposed for clinical measurement of intraocular pressure (IOP). It is postulated that the change of fluid pressure in a fluid-filled elastic shell, such as the eye, would change the apparent elasticity of the shell, which in turn would change its frequency of resonance. If a standardized normal range of resonance for the human eye can be found, any abnormality in the resonance can then be used to detect abnormalities in the IOP. Preliminary experiments are performed using eviscerated and enucleated human and pig eyes. IOP is varied by insertion of a saline fluid filled catheter with a hydrostatic pressure. Doppler ultrasound is used to find the amplitude of vibration of the sclera. As little as 4 mm Hg change in IOP is detected