The effects of beta-blockers on ocular blood flow in patients with primaryopen angle glaucoma: a color doppler imaging study

PURPOSE. TO evaluate the effects of four commonly used beta-blockers on ocu lar blood flow in patients with primary open angle glaucoma (POAG). METHODS. Eighty eyes of 40 subjects with POAG were included in the study. S ubjects were randomly divided into four groups given timolol maleate 0.50%, betaxolol HCl 0.50%, carteolol 1% or levobunolol 0.50% drops, applied twic e daily tone drug to each group). Before beginning the treatment and at the end of the first month ocular blood flow velocity was measured using the c olor Doppler imaging (CDI) method. In the ophthalmic artery (OA), central r etinal artery (CRA) and temporal posterior ciliary artery (TPCA) the peak s ystolic (PS) and end-diastolic (ED) blood flow velocities were measured and resistive index (RO values were calculated. The results within each group were analysed using the matched paired student's t-test. The data between g roups was compared with one-way analysis of variance (ANOVA) and Tukey-Kram er multiple comparison tests. RESULTS. The timolol group showed a significant increase in RI values of TP CA. In the betaxolol group RI decreased significantly in CRA and TPCA, wher eas in the carteolol group there was a significant decrease only in CRA. In the levobunolol group there was no change in any artery, CONCLUSIONS. Betaxolol seemed to have a greater vasodilator effect than car teolol, and levobunolol had no effect on the retinal and choroidal vasculat ure. Timolol may have some vasoconstrictive effect in the ciliary vasculatu re.