Retinal Blood Flow after Dynamic Exercise

Abstract

Abstract: : Purpose:To evaluate the retinal blood flow before and after the increase of systemic blood pressure to assess the autoregulation in healthy subjects. Methods:Twenty eyes of twenty healthy volunteers were examined. All the subjects’ eyes were examined by slit–lamp and ophthalmoscopy and only healthy eyes were included in the study. Visual fields were assessed by Frequency Doubling Technology screening program. The retinal blood flow was assessed by HRF, while the systemic pressure was assessed by a portable electronic sphygmomanometer. Furthermore IOP was always measured by Goldmann tonometer immediately after HRF. All measurements of physiological and flow parameter were performed with subjects seated at rest and then immediately after dynamic exercise. Results: The IOP decreased significantly after dynamic exercise, while the heart rate and the systemic artery pressure increased significantly. At the baseline the mean retinal blood flow was 276.8 +/– 80.7 in the supero–temporal area, 243.4 +/– 63.68 in the supero–nasal area, 258.2 +/– 67.37 in the infero–temporal area and 243.9 +/– 72.24 in the infero–nasal area. After dynamic exercise the mean retinal blood flow was 249.8 +/– 86.78 in the supero–temporal area, 248.7 +/– 63.87 in the supero–nasal area, 245.4 +/– 83.85 in the infero–temporal area and 228.8 +/– 62.53 in the infero–nasal area. No significant change in retinal blood flow was found. Conclusions:Our data support the hypothesis that in normal subjects autoregulation is sufficient to compensate the increase in blood pressure and maintains a stable retinal blood flow after exercise.

Keywords: optic disc • optic flow • retina