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

Abstract

To assess the relation between ocular perfusion pressure and blood flow velocity in the central retinal artery in patients with acral vasospasm. Eighteen otherwise healthy subjects with acral vascular 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 pressure and blood flow velocity in the central retinal artery were determined by applanation tonometry and color Doppler imaging, respectively. The peak systolic velocity, end-diastolic velocity, and resistivity index were assessed. Correlations between the mean ocular perfusion pressure (2/3 x [2/3 x diastolic blood pressure + 1/3 x systolic blood pressure] - intraocular pressure) and blood flow velocities in the central retinal artery were determined by the Pearson linear correlation factor. The Student t test was used to evaluate differences between controls and subjects with vasospasm. 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 velocities and the resistivity index of the central retinal artery correlated significantly with the mean ocular perfusion pressure (R = 0.49, P = .04 P = .01; and R = -0.67, P = .002, respectively). Such correlations were not found in the control group. An altered blood flow regulation is suggested in the ocular circulation of patients with acral vasospasm.