[Biomechanics of the lamina cribrosa: A determining factor in glaucomatous neuropathy. A review of the literature].

Glaucoma is a chronic optic neuropathy characterized by progressive sclero-laminar remodeling. The main factor at the origin of these deformations is the intraocular pressure (IOP), the effect of which varies according to the biomechanical properties of the individual lamina cribrosa (LC). In this environment, the LC represents a malleable zone of weakness within a rigid corneoscleral shell. It is a dynamic structure whose movements play a key role in the pathogenesis of glaucoma: displacing it posteriorly, in addition to contributing to the characteristic appearance of glaucomatous cupping, would increase constriction on the nerve fibers and the laminar capillaries. Often incorrectly considered permanent in adults, these deformations have a certain degree of reversibility, which is currently better characterized thanks to progress in imaging techniques. The occurrence of anterior displacement and laminar thickening following a reduction in IOP could thus constitute a good prognostic factor by reducing mechanical stress on this region. These changes would tend to reduce laminar pore tortuosity and shear forces, which are probably key mechanisms of axonal loss in glaucoma.