Effect of topical timolol on optic nerve head circulation in the cynomolgus monkey.
OBJECTIVE
To evaluate the effect of topical timolol on the optic nerve head (ONH) circulation in the cynomolgus monkey.


METHODS
Eight cynomolgus monkeys were used. Timolol (0.5%, 30 microL) was instilled twice daily into 1 eye and physiological saline into the other eye for 7 consecutive days. The ONH tissue blood velocity (NB(ONH)) was determined using the laser speckle method. The determinations of NB(ONH) were carried out before the first instillation and 4 hours after the first, the seventh and the last instillation. The IOP was measured periodically. All measurements were performed in a masked manner.


RESULTS
Twice daily 7-day instillation of 0.5% timolol showed no significant effect on the NB(ONH) in either eye, while the IOP was significantly decreased in both eyes.


CONCLUSIONS
In the cynomolgus monkey, the ONH circulation was not affected by 7-day twice daily topical timolol treatment.
Ishii
K
K
Eye Clinic, Omiya Red Cross Hospital, Yono, Saitama, Japan.
Araie
M
M
D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001775:Blood Circulation / Q000187:drug effects; D001783:Blood Flow Velocity; D007429:Intraocular Pressure / Q000187:drug effects*; D017078:Laser-Doppler Flowmetry; D008252:Macaca fascicularis; D009883:Ophthalmic Solutions; D009898:Optic Disk / Q000098:blood supply* / Q000502:physiology; D013997:Time Factors; D013999:Timolol / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D009883:Ophthalmic Solutions; D013999:Timolol