Intraocular Pressure (IOP) Measurement Using Sound Waves

Abstract

Biomechanics has been an area of increasing relevance for ophthalmologists in the last decade. The measurement of accurate Intraocular pressure (IOP) is one of the significant factors in the proper diagnosis of glaucoma. The increase in pressure could deteriorate the loss of nerve fibers, eventually leading to complete blindness. Glaucoma is the 2nd most common form of blindness after a cataract, as it is developed slowly and usually without any significant symptoms. Raised IOP can cause serious ill effects in the eye, which could lead to temporary or permanent vision loss. Therefore, efficient IOP measurement is clinically essential for managing and diagnosing different types of glaucoma. In this thesis, my research will focus on verifying Imbert-Fick’s law, which is the main principle behind the tonometer. In other words, to understand the effect of corneal biomechanics on the IOP by experimental calculations and finite element analysis. It is essential to mention that another graduate student will focus on using sound waves to measure IOP. Since my research focused on Imbert-Fick’s law, we manufactured an artificial cornea of varying thicknesses from 0.3-0.7 mm using a silicone rubber polymer of Young’s Modulus 0.25 MPa. A controlled experimental test setup, to validate Imbert Fick’s law using a rebound tonometer and the Schiotz tonometer, was built. The initial outcome of this work is that the rebound tonometer underestimates the actual pressure value behind the artificial cornea in most cases. Finite element analyses have also been carried out for the same experimental test cases, with FEA results producing contrary results to the experimental values.

Date of Award	Dec 2022
Original language	American English
Supervisor	Nader Vahdati (Supervisor)