Effect of hypertension on foveolar choroidal haemodynamics

Aims: To assess the effect of systemic hypertension on the choroidal circulation in subjects with a normal eye examination. Methods: Laser Doppler flowmetry was used to determine relative choroidal blood velocity (Ch(vel)), volume (Ch(vol)), and flow (Ch(flow)) in the centre of the fovea. Measurements were obtained in 15 eyes of 15 subjects with systemic hypertension. The mean average duration of hypertension was 11 (SD 6) years. Findings obtained in these patients were compared with those of 15 eyes of 15 age matched healthy controls. All subjects had normal eye examinations. Results: No significant differences in Ch(vel), Ch(vol), and Ch(flow), were found between the subjects with and without systemic hypertension despite a 17% higher perfusion pressure (PP) in patients with hypertension. No significant correlation was found between mean arterial pressure or PP and the choroidal circulatory parameters. It was estimated that there is a 90% power to detect a 35% difference in Ch(flow) between the two groups. Conclusion: Systemic hypertension does not seem to have a large effect on the choroidal circulation in hypertensive patients that are controlled by antihypertensive therapy. Further studies are needed to elucidate whether systemic hypertension has an effect on the choroidal circulation in patients with ocular diseases