OBJECTIVES :
To evaluate
the ocular hypertensive effect of 2% ibopamine in patients with open-angle
glaucoma vs. healthy subjects in comparison with 10% phenylephrine.
METHODS :
A double
masked, randomized, cross-over, controlled study in two centres with 3 days
wash-out was performed. Twenty healthy subjects and 20 patients with open-angle
glaucoma in single drug therapy with beta-blockers were evaluated with
tonometry at baseline and 5, 45, 90, 180, 270, 360 minutes after drug
instillations. Pupillary diameter was also assessed. Efficacy and tolerability
parameters were evaluated by analysis of variance for continuous data and
Friedman’s Chi-Square test and Wilcoxon’s test for paired data for categorical
data.
RESULTS :
A
statistically significant increase (p<0.001) of intraocular pressure (IOP)
was observed already on the first tonometry performed 45 minutes after
instillation in the glaucoma patients group treated with 2% ibopamine. At
subsequent measurements, IOP slowly decreased returning to basal values within
360 minutes. In the 10% phenylephrine treatment group no patients presented any
increase in IOP. Healthy volunteers treated with ibopamine and phenylephrine
did not show any variation in IOP. The mydriatic activity of both drugs is
substantially superimposable, being effective already at the first measurement
performed 45 minutes after instillations. Analysis performed on heart rate did
not show any significant effects of treatment in glaucomatous patients and
healthy volunteers.
CONCLUSION :
The results
of this study support previous data concerning the characteristic activity of
ibopamine to stimulate aqueous humor production and confirm its potential
employment as an interesting and simple tool for the ophthalmologist in the
early detection of alterations in aqueous humor outflow.