A Finite Element Model Project to Study the Mechanical Behavior of the Macula Region During Ocular Movements

Aim: To present a Finite Element Model of the macula region of the eye’s posterior pole for structural analysis during ocular movements. Method: We used software ImageJ, Meshlab and Spaceclaim for image processing and meshing to create a patient specific geometry of the posterior pole from Ocular Coherent Tomography images. Then we used Ansys software to create a predominately linear FEM model to simulate the action of inferior oblique muscle on the posterior pole. We performed Static analysis and Eigenvalue buckle analysis in different biomechanical scenarios. Results: We recorded the stress, strains and volumetric changes on the posterior pole layers. We reproduced known clinical entities like partial detachment of vitreous cortex, macula rhexis and pigment epithelial detachments. We found that removal of cortex may have a protective effect on the retina by transferring stress and buckling events from the retina and its interfaces to the deeper layers of choroid and sclera. Conclusion: This is the first time that a FEM demonstrates the effects of ocular movements and particularly of inferior oblique muscle action, supporting our hypothesis that repetitive strain from ocular motility may be a common pathogenetic factor in various, potentially blinding, diseases of the macula.