The comparative cardiovascular, pulmonary, ocular blood flow, and ocular hypotensive effects of topical travoprost, bimatoprost, brimonidine, and betaxolol.
OBJECTIVE
This study evaluated systemic and ocular acute safety and intraocular pressure (IOP)-lowering efficacy of travoprost 0.004% and bimatoprost 0.03%, compared to brimonidine 0.2% and betaxolol 0.25% in healthy subjects.


METHODS
Nineteen (19) young men, ages between 24 and 42, were enrolled in a single-center, institutional randomized, double-masked, crossover clinical trial. Baseline IOP, heart rate, blood pressure, and respiratory rate were recorded at hour 0. At minute 30, heart rate, blood pressure, respiratory rate, and spirometry were measured. At hour 1, color Doppler imaging of retrobulbar vessels was performed. At hour 2, heart rate, blood pressure, and respiratory rate were measured; spirometry and a 15-minute treadmill test were performed. The same protocol was applied after one drop of a study medication was instilled into each eye on four subsequent visits at 5-day intervals.


RESULTS
Travoprost and bimatoprost did not cause significant reductions in systolic blood pressure during exercise and recovery. The mean respiratory rate and forced expiratory volume in 1 second were not significantly altered by any study medication. Travoprost reduced the resistive index and increased blood velocities in the ophthalmic artery and its branches. Bimatoprost caused a significant increase in end diastolic velocity of the ophthalmic artery. At hour 6, all medications reduced IOP significantly (p < 0.05). The most frequent ocular side effect of travoprost and bimatoprost was conjunctival hyperemia.


CONCLUSIONS
Travoprost and bimatoprost were found to be systemically safe and caused an increase in blood-flow velocities of the retrobulbar vessels after a single-dose application. Their ocular hypotensive effect was comparable to that of brimonidine and greater than that of betaxolol in healthy subjects.
Kocatepe University School of Medicine, Department of Ophthalmology, Afyon, Turkey.
Umit Ubeyt
UU
Inan
Sitki Samet
SS
Ermis
Ayse
A
Orman
Ersel
E
Onrat
Aylin
A
Yucel
Faruk
F
Ozturk
Ali
A
Asagidag
Atac
A
Celik
D000287:Administration, Topical; D000328:Adult; D000577:Amides; D015784:Betaxolol / Q000008:administration & dosage* / Q000633:toxicity; D000069580:Bimatoprost; D000068438:Brimonidine Tartrate; D002319:Cardiovascular System / Q000187:drug effects*; D003008:Cloprostenol / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000633:toxicity; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005123:Eye / Q000098:blood supply / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects* / Q000502:physiology; D008055:Lipids / Q000008:administration & dosage* / Q000633:toxicity; D008297:Male; D015814:Ocular Hypotension / Q000139:chemically induced; D011446:Prospective Studies; D011652:Pulmonary Circulation / Q000187:drug effects / Q000502:physiology; D011810:Quinoxalines / Q000008:administration & dosage* / Q000633:toxicity; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D000069557:Travoprost
D000577:Amides; D008055:Lipids; D011810:Quinoxalines; D003008:Cloprostenol; D000068438:Brimonidine Tartrate; D015784:Betaxolol; D000069580:Bimatoprost; D000069557:Travoprost