Autoregulation and neurovascular coupling in the optic nerve head.

Impairments of autoregulation and neurovascular coupling in the optic nerve head play a critical role in ocular pathologies, especially glaucomatous optic neuropathy. We critically review the literature in the field, integrating results obtained in clinical, experimental, and theoretical studies. We address the mechanisms of autoregulation and neurovascular coupling in the optic nerve head, the current methods used to assess autoregulation--including measurements of optic nerve head blood flow (or volume and velocity)--blood flow data collected in the optic nerve head as pressure or metabolic demand is varied in healthy and pathologic conditions, and the current status and potential of mathematical modeling work to further the understanding of the relationship between ocular blood flow mechanisms and diseases such as glaucoma.