Abstract
Purpose: :
Increased intraocular pressure (IOP) is the most important risk factor for the development of glaucoma. Consequently, most of the therapies available today focus on lowering IOP. However, there is also evidence that altered blood flow regulation may play a role in the progression of the disease. In the present study, we tried to investigate whether topical treatment with a prostaglandin analogue alters choroidal blood flow regulation either in response to an increase in systemic blood pressure or to a suction cup induced increase of IOP.
Methods: :
Twenty-four healthy male volunteers were included in this prospective, balanced, placebo-controlled parallel group study. Choroidal blood flow was measured with laser Doppler flowmetry. To test autoregulation, ocular perfusion pressure was either changed by the means of a 6 minutes squatting period or by a suction cup induced increase of IOP. Measurements were performed before drug administration and at the end of a 2 week topical administration of either latanoprost or placebo.
Results: :
At baseline conditions, no differences between the latanoprost and the placebo group were observed. Fourteen days treatment with latanoprost did neither affect choroidal blood flow nor systemic blood pressure, but led to a decrease in IOP. Latanoprost did not alter the response in ocular perfusion pressure to isometric exercise or to an artificial IOP increase. The autoregulatory plateau was, however, wider during both stimuli (p<0.05).
Conclusions: :
The present study indicates that choroidal blood flow regulation is improved over physiological blood flow regulation in healthy young subjects after a pharmacologically induced decrease in IOP. This is seen in the absence of an effect of prostaglandin on choroidal blood flow under baseline conditions. Hence, the present result is compatible with the idea that the effect is related to the reduction in IOP.
Clinical Trial: :
www.clinicaltrials.gov NCT00712400
Keywords: choroid • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials