Is vascular regulation in the central retinal artery altered in persons with vasospasm?

Objective: To assess the relation between ocular perfusion pressure and blo od flow velocity in the central retinal artery in patients with acral vasos pasm. Subjects and Methods: Eighteen otherwise healthy subjects with acral vascul ar dysregulation, as demonstrated by nail-fold capillaroscopy, and 18 age- and sex-matched healthy volunteers without vasospasm were recruited. After subjects had rested for 20 minutes in a supine position, intraocular pressu re and blood flow velocity in the central retinal artery were determined by applanation tonometry and color Doppler imaging, respectively. The peak sy stolic velocity, end-diastolic velocity, and resistivity index: were assess ed. Correlations between the mean ocular perfusion pressure (2/3 x [2/3 x d iastolic blood pressure + 1/3 x systolic blood pressure] - intraocular pres sure) and blood flow velocities in the central retinal artery were determin ed by the Pearson linear correlation factor. The Student t test was used to evaluate differences between controls and subjects with vasospasm. Results: The mean +/-SD ocular perfusion pressure was 42.0 +/- 7.4 mm Hg in the group with vasospasm and 47.1 +/- 6.5 mm Hg in the control group (P = .04). In the subjects with vasospasm, the peak systolic and end-diastolic v elocities and the resistivity index of the central retinal artery correlate d significantly with the mean ocular perfusion pressure (R = 0.49, P = .04; R = 0.58, P = .01; and R = -0.67, P = .002, respectively). Such correlatio ns were not found in the control group. Conclusion: An altered blood flow regulation is suggested in the ocular cir culation of patients with acral vasospasm.