Color Doppler imaging discloses reduced ocular blood flow velocities in nonexudative age-related macular degeneration

PURPOSE: To study ocular perfusion defects in age-related macular degenerat ion. METHODS: Twenty-five subjects with nonexudative age-related macular degener ation were compared with 25 age-matched control subjects in studies of flow velocities in several retrobulbar vessels. Color Doppler imaging, which wa s performed by an examiner who was masked to the subjects' assignment to th e control or age-related macular degeneration group, measured peak systolic and end diastolic velocity in the ophthalmic, central retinal, and nasal a nd temporal posterior ciliary arteries of one eye. A resistive index was ca lculated from the peak systolic and end diastolic velocity. RESULTS: Subjects with nonexudative age-related macular degeneration showed a consistent trend toward lower peak systolic and end-diastolic velocities in the posterior ciliary arteries. For example, in the nasal posterior cil iary artery, the mean end diastolic velocity measured 1.45 +/- 0.34 cm per sec in the age-related macular degeneration group compared with 1.96 +/- 0. 66 cm per sec in the control group, yielding a 26% decrease in the age-rela ted macular degeneration group, which represented the largest difference an d was highly statistically significant (P = .0012). The resistive index was not significantly altered in the nasal or temporal posterior ciliary arter y. Subjects with nonexudative age-related macular degeneration did nor diff er from control subjects in peak systolic velocity, end diastolic velocity, or resistive index in the ophthalmic artery. In the central retinal artery , the end diastolic velocity was lower (1.37 +/- 1.95 cm per sec vs 1.95 +/ - 0.66 cm per sec), whereas the resistive index was higher (0.83 +/- 0.05 v s 0.76 +/- 0.06 cm per sec), in the age-related macular degeneration group; these results were highly statistically significant (P = .0007 and P < .00 01, respectively). CONCLUSIONS: Retrobulbar vascular changes in nonexudative age-related macul ar degeneration subjects include reduced flow velocities in the nasal and t emporal posterior ciliary arteries. The reduced peak systolic velocity, com bined with the reduced end diastolic velocity at a constant resistive index , seen in nonexudative age-related macular degeneration, is consistent with reduced bulk flow in these vessels, suggesting that choroidal perfusion is abnormal in this form of age-related macular degeneration. The changes in the central retinal artery suggest there may be a more generalized perfusio n abnormality beyond the choroid in patients with age-related macular degen eration or that the central retinal artery exhibits a secondary autoregulat ory response to a primary change elsewhere. (Am J Ophthalmol 1999; 128:75-8 0. (C) 1999 by Elsevier Science Inc. All rights reserved.)