Assessment of intraocular pressure with an artificial model eye mimicking human eye

Abstract

AbstractPurposeGiven that clinical significance of intraocular pressure (IOP), accurate IOP measurements are crucial. However, measurement of IOP is affected by corneal properties such as thickness, curvature, and biomechanical properties. To derive the quantitative relationship between corneal variables and IOP, it is valuable to create a theoretical model that represents these various properties of the cornea. We have constructed optically transparent artificial eye phantoms, which have closely similar to a human eye. The purpose of this study is to evaluate the clinical applicability of artificial eye by understanding and quantifying the IOP measurement.MethodThe artificial model eye has made of polydimethylsiloxane (PDMS) and its inside is filled with glycerol solution. We developed three different shapes of model eye to reflect the variation in corneal diameter and radius of curvature. Corneal properties (i.e., elasticity) were varied according to the formulation of PDMS (Young’s modulus: 1.7 MPa, 0.7 Mpa, and 0.4 MPa) and corneal thickness was differed by varying the concentration of ethylene glycol. The effect of each variable on the measurement of IOP was examined quantitatively using Goldmann applanation tonometry.ResultsThe IOP of the model eye showed significant positive correlation with corneal thickness in all shapes of model eye (all p < 0.001). The range of the IOP changed according to Young’s modulus of model eye. (12–80 mmHg, 1–80 mmHg, and 1–32 mmHg in model eyes with 1.7 MPa, 0.7 MPa, and 0.4 MPa, respectively). Relationship between the IOP and thickness differed depending on the Young’s modulus of the model eye.ConclusionsThe IOP of the developed artificial eyeball was successfully measured by Goldmann applanation tonometer in a similar manner to a real human eye. This finding suggests that the artificial model eye may have a value as an independent, reproducible sample that allows comparison of tonometers.