Objective: To assess the relation between ocular perfusion pressure and blood flow velocity in the central retinal artery in patients with acral vasospasm.
Subjects and methods: 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.
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 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.
Conclusions: An altered blood flow regulation is suggested in the ocular circulation of patients with acral vasospasm.