Effect of systemic hypertension on foveolar choroidal blood flow in age related macular degeneration

Abstract

AIM: To investigate the effect of systemic hypertension (SH) on the foveolar choroidal circulation in patients with age related macular degeneration (AMD). METHODS: This study included 163 study eyes with early AMD characteristics of 124 AMD patients. Study eyes had visual acuity of 20/40 or better, drusen > or =63 microm, and/or RPE hypertrophy. 56 of the AMD patients had a history of SH and 47 of these patients were receiving antihypertensive medications. Laser Doppler flowmetry (Oculix) was used to assess relative choroidal blood velocity (ChBVel), volume (ChBVol), and flow (ChBFlow) in the centre of the fovea of the study eyes. Differences in the mean haemodynamic parameters between groups of eyes were assessed using analysis of variance (ANOVA) and a test of linear trend, with adjustment for the correlation between eyes of the same patient. RESULTS: AMD patients with SH showed decreased ChBFlow in comparison with those without SH (ANOVA, p = 0.02). This association was maintained after adjustments for multiple factors (p = 0.04). CONCLUSIONS: AMD patients with SH have lower ChBFlow than those without SH. This decrease in choroidal blood circulation may help explain the mechanism by which systemic hypertension may contribute to the progression of AMD and the development of choroidal neovascularisation.