Development of the Patient-Specific Ocular Models using Optical Coherence Tomography Images: Glaucoma Model

Glaucoma is the leading cause of blindness worldwide. It is an eye disease characterized by progressive loss of retinal ganglion cell (RGC) axons. Biomechanical factors are believed to play a central role in the RGC loss, whereas the specific mechanism remains unknown. Our goal is to propose a methodology to build patient specific ocular models to characterize the effect of intraocular (IOP) and intracranial pressure (ICP) on the optic nerve head (ONH). Optical coherence tomography (OCT) images of the eyes of six patients were obtained and three-dimensional models of the ONH region were reconstructed. These were further embedded into a generic cornea-scleral shell to create complete eye models. We used finite element analysis to determine the effects of elevated levels of IOP with varying levels of ICP on the ONH biomechanical environment. Maximum principal and shear strains were computed and used for assessing ONH damage. Our results reveal cases with substantial shear strains in lamina cribrosa and indicate that the inter-individual geometric variations affect ONH biomechanics.