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Abstract #15675 Published in IGR 2-3
A comparative study on the effects of apraclonidine and timolol on the ophthalmic blood flow velocity waveforms
Oruç S; Sener ECInternational Ophthalmology 1999; 23: 69-73
PURPOSE: To evaluate the effects of optical timolol and apraclonidine on retrobulbar blood flow velocity waveforms in a group of healthy volunteers. METHODS: Apraclonidine 1% and timolol maleate 0.5% single dose administrations were crossed-over double-masked in 12 healthy volunteers. The intraocular pressure (IOP) measurements were followed by Doppler examination of the ophthalmic artery and central retinal artery. RESULTS: IOP was significantly reduced in both treated and fellow eyes after timolol (p = 0.003, p = 0.04, respectively), and after apraclonidine (p = 0.002, p = 0.01, respectively). After apraclonidine administration, end diastolic velocity and mean velocity decreased and pulsatility index increased in the ophthalmic artery of both treated and fellow eyes.Resistivity index increased and peak systolic velocity only decreased in the ophthalmic artery of treated eyes. All Doppler indices remained nonsignificant for the central retinal artery of both eyes. After timolol administration, there were no significant changes in the Doppler indices in the ophthalmic or central retinal arteries of treated and fellow eyes. CONCLUSIONS: Topical timolol and apraclonidine significantly reduced IOP. Single dose administration of apraclonidine 1% increased vascular impedance distal to the ophthalmic artery. On the other hand, timolol 0.5% had no effect on vascular impedance.
Dr. S. Oruç, Department of Ophthalmology, Adnan Menderes University, Aydin, Turkey
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
11.3.3 Apraclonidine, brimonidine (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)
11.3.4 Betablocker (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)
