Myelin Distribution at the Optic Nerve Myelination Transition Zone Influences Axonal Biomechanics
This study investigates the potential role of mechanical discontinuity at the myelination transition zone (MTZ) of the optic nerve in early glaucomatous damage. By developing a multiscale finite element model that integrates the macroscopic globe with the microscopic lamina cribrosa–axon architecture, the work quantifies, for the first time, how different MTZ boundary configurations influence axonal biomechanical responses under intraocular pressures of 15 and 45 mmHg. The results demonstrate that the unmyelinated region endures substantially higher mechanical loads, and posterior displacement of the MTZ markedly exacerbates stress and strain discontinuities across the interface. These findings highlight MTZ geometry as a critical determinant of the local mechanical microenvironment surrounding axons, offering a novel biomechanical perspective on the pathogenesis of glaucoma.