Search

A randomized double-blind study of aqueous humor flow and intraocular pressure measurements before and four hours after instillation of placebo and beta-blocker eyedrops, was carried out in 40 hypertensive patients. The treated and non-treated patients either did or didn't show an optic disc excavation and a visual field defect. Hypertensive patients with a previous tension treatment will stop therapy on a 3-week period up to an increase of their own ocular tension value greater than or equal to 3 mmHg. The intraocular pressure statistically decreased of 20.8% four hours after topical placebo, the aqueous humor flow remaining unchanged. In this study, timolol eyedrops induced a greater decrease of the aqueous humor flow (39%), followed equally by betaxolol (23.8%) and carteolol (20.42%). Timolol and betaxolol eyedrops equally induced a significant decrease of the intraocular pressure. There was no effect of carteolol on the intraocular pressure. The outflow facility was independent of the instilled beta-blocker eyedrop.

Two fluorophotometric methods, by instillation and oral route, allowed the aqueous humor flow measurement and apparent outflow resistance calculation in normal and hypertensive subjects. There was no statistically significant difference between the two methods in the aqueous humor flow of hypertensive patients and normal subjects. On the contrary, there was an increase of the outflow resistance in hypertensive patients in relation to normal subjects. Finally, oral route fluorophotometry allowed the individualization and calculation of a coefficient of aqueous humor production from the iris, which is statistically increased in hypertensive in comparison with normal subjects. Subsequent studies thanks to this fluorophotometric method by oral route, which interest is certain in treated hypertensive patients, should allow to determine the action site of the drug and to quantify its efficiency.