Numerical Simulation of the Early Stages of Glaucoma in Human Eye

Background: The eye is one of the most vital organs of human body, and glaucoma is the second-leading cause of blindness after cataracts in the world. However, glaucoma is the leading cause of preventable blindness. The main objective of this study is to investigate intraocular pressure (IOP), stress, strain, and deformation in the retina in early stages of glaucoma. Methods: In this study, a model of the human eye is numerically investigated. The aqueous humor pressure is considered as 30, 35, and 40 mmHg and compared with normal eye pressure. The problem is considered as transient 3D and accurate. Comparison between obtained results shows that the model has been applied. Eye components are also considered with their real properties. Due to the inappreciable effects of turbulence and temperature variation, these effects have been neglected. To determine the pressure field, a two-way fluidstructure interaction is applied, and then, the results are used in a one-way fluidstructure interaction to determine the amount of stress, strain, and deformation of the retina. Results: The maximum deformation in the retina of a glaucoma patient is about 0.33 mm higher than a normal eye, the maximum stress is about 1,300 Pa higher than a normal eye, and the maximum strain is about 0.06 higher than a normal eye. Conclusion: In patients with increased IOP, the amount of deformation in the retina has increased, and the maximum deformation occurs near the optic disc in all cases. Furthermore, maximum stress and maximum strain occur at the place of maximum deformation.