Relationship between blood flow velocities in retrobulbar vessels and laser Doppler flowmetry at the optic disk in glaucoma patients

The relationship between blood flow velocities in retrobulbar vessels and b lood flow at the optic nerve in glaucoma patients was assessed in a prospec tive study, The Heidelberg retina flowmeter (HRF) was used to assess optic nerve head blood flow in 13 open-angle glaucoma patients. In the same patie nts, color Doppler imaging (CDI) measurements were obtained from the ophtha lmic artery, the central retinal artery and the posterior ciliary arteries. Using data for one randomly selected eye per subject, correlations between HRF recordings and CDI measurements were evaluated by means of Spearman's rank correlation factor. All three HRF parameters correlated with CDI measu rements obtained from retrobulbar vessels, The most marked correlations wer e those of the HRF parameter 'volume' with the end-diastolic velocity in th e ophthalmic artery and the medial posterior ciliary artery (R = 0.79, p = 0.0012 and R = 0.81, p = 0.0007, respectively), and the peak systolic veloc ity in the lateral posterior ciliary artery (R = 0.82, p = 0.0006). The pre sent study suggests that glaucoma patients with altered blood flow in retro bulbar vessels are likely to show an alteration in optic nerve blood flow a s measured with the HRF.