Demystifying the Air Puff Test: A New Approach for Accurate Intraocular Pressure Measurements
Authors: Maklad, O., Eliasy, A., Chen, K.J., Theofilis, V., Elsheikh, A.
Journal: International Journal of Environmental Research and Public Health
Publication Date: Dec 2020
(a) Arbitrary Lagrangian–Eulerian (ALE) deforming mesh shown on a quarter model of the air puff; and (b) comparison of apical deformation with finite element only models in absence of ALE deforming mesh.
Summary:
Our research focuses on improving the numerical simulation of the non-contact tonometry test, also known as the "air puff test," using an arbitrary Lagrangian-Eulerian (ALE) deforming mesh. This test is crucial for estimating intraocular pressure (IOP), which plays an essential role in managing glaucoma and detecting keratoconus, among other eye-related conditions.
Traditionally, the air puff test involved blowing a quick puff of air onto the cornea, causing it to deform. The level of deformation was then used to estimate the pressure inside the eye. However, this method has faced accuracy challenges due to the cornea's unique geometry and material properties. Our study aims to address these challenges by presenting an improved numerical simulation that can lead to more accurate IOP measurements and a better understanding of the corneal material's behavior.
Using the adaptive deforming mesh in our numerical simulation, we discovered that the pressure distribution on the cornea changes during the test. There was a mean decrease in maximum pressure (at the corneal apex) of 6.29 ± 2.2%, and a development of negative pressure on a peripheral corneal region 2–4 mm away from the cornea's center.
Our findings contribute to a deeper understanding of how the air puff test interacts with the cornea and its biomechanical parameters. This research will ultimately lead to more accurate IOP measurements and improved corneal material behavior estimation, allowing for better detection and management of various eye conditions.