The optic nerve head as a biomechanical structure: a new paradigm for understanding the role of IOP-related stress and strain in the pathophysiology of glaucomatous optic nerve head damage.
We propose here a conceptual framework for understanding the optic nerve head (ONH) as a biomechanical structure. Basic principles of biomechanical engineering are used to propose a central role for intraocular pressure (IOP)-related stress and strain in the physiology of ONH aging and the pathophysiology of glaucomatous damage. Our paradigm suggests that IOP-related stress and strain (1) are substantial within the load-bearing connective tissues of the ONH even at low levels of IOP and (2) underlie both ONH aging and the two central pathophysiologies of glaucomatous damage--mechanical failure of the connective tissues of the lamina cribrosa, scleral canal wall, and peripapillary sclera, and axonal compromise within the lamina cribrosa by a variety of mechanisms. Modeling the ONH as a biomechanical structure generates a group of testable hypotheses regarding the central mechanisms of glaucomatous damage and provides a logic for classifying the principal components of the susceptibility of an individual ONH to a given level of IOP.
Burgoyne
Claude F
CF
LSU Eye Center, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite B, New Orleans, LA 70112, USA. cburgo@lsuhsc.edu
Downs
J Crawford
JC
Bellezza
Anthony J
AJ
Suh
J-K Francis
JK
Hart
Richard T
RT
D000818:Animals; D001696:Biomechanical Phenomena; D003238:Connective Tissue / Q000503:physiopathology; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008954:Models, Biological; D009898:Optic Disk / Q000503:physiopathology*; D009901:Optic Nerve Diseases / Q000503:physiopathology*; D013312:Stress, Physiological / Q000503:physiopathology*