An Investigation of the Effects of Timolol Maleate and Betaxolol HCL on Central Retinal, Posterior Ciliary and Ophthalmic Arteries with Color Doppler Ultrasound

Authors: Orhan BAYKAL, Ali ÇOLAK, Mete ÖZDİKİCİ, Aşkım TÜFEKÇİ, İbrahim KOÇER

Abstract: Optic neuropathy in glaucoma is associated wtih vascular pathologies. Although there are different methods for follow-up of glaucoma, no effective method has been estabilshed yet with regard to the investigation of alterations in vascular hemodynamics, /beta adrenergic blockers used in treatment may effect hemodynamics of central retinal artery (CRA) and posterior ciliary arteries (PCA). This study included 43 healthy subjects with no systemic or ocular disease. We aimed to investigate the effects of Timolol in 15 cases, Betoxolol in 14 cases and placebo in 14 cases on peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) of the above CRA, PCA and ophthalmic artery (OA) with color doppler ultrasonograpy. Both drugs reduced intraocular pressure to a significant extent. Timolol increased only the value of the peak systolic velocity of the postterior cliary artery (p=0.05). Betaxolol had no effect on vascular hemodynamics. When we compared the effects of timolol on orbital hemodynamics to those of betaxolol, we were not able to find any significant difference. There was no statistical difference between the study and control groups in terms of PSV, EDV and RI obtained from CRA, PCA and OA (P>0.05).

Keywords: Glaucoma, Timolol, Betaxolol, Color Doppler Ultrasound