Laser Doppler flowmetry of the optic nerve head in glaucoma.

The introduction of ocular laser Doppler flowmetry during the last decade has greatly improved our ability to noninvasively assess the hemodynamics of the optic nerve in patients with glaucoma. Studies with laser Doppler flowmetry have determined that blood flow in the optic nerve is diminished in eyes with primary open-angle glaucoma and that this decrease occurs in patterns consistent with glaucomatous damage. Lower systemic blood pressure is associated with lower blood flow, supporting numerous studies linking systemic hypotension to glaucomatous damage. This direct relationship between systemic blood pressure and optic nerve blood flow has significant implications in terms of the etiology of glaucomatous damage and the treatment of ocular and systemic diseases in the glaucoma patient. Further research is needed to determine whether the circulatory abnormalities of the optic nerve head are a cause or a result of glaucomatous damage.