Evaluation of monkey intraocular pressure by rebound tonometer.
OBJECTIVE
To evaluate the usefulness of the TonoVet rebound tonometer in measuring intraocular pressure (IOP) of monkeys.


METHODS
The accuracy of the TonoVet rebound tonometer was determined in cannulated eyes of anesthetized rhesus monkeys where IOP was controlled by adjusting the height of a connected perfusate reservoir. To assess the applicability of the equipment through in vivo studies, the diurnal fluctuation of IOP and effects of IOP-lowering compounds were evaluated in monkeys.


RESULTS
IOP readings generated by the TonoVet tonometer correlated very well with the actual pressure in the cannulated monkey eye. The linear correlation had a slope of 0.922+/-0.014 (mean+/-SEM, n=4), a y-intercept of 3.04+/-0.61, and a correlation coefficient of r(2)=0.97. Using this method, diurnal IOP fluctuation of the rhesus monkey was demonstrated. The tonometer was also able to detect IOP changes induced by pharmacologically active compounds. A single topical ocular instillation (15 microg) of the rho kinase inhibitor, H1152, produced a 5-6 mmHg reduction (p<0.001) in IOP, lasting at least 4 h. In addition, topical administration of Travatan, a prostaglandin agonist, induced a small transient IOP increase (1.1 mmHg versus vehicle control; p=0.26) at 2 h after treatment followed by a pressure reduction at 23 h (-2.4 mmHg; p<0.05). Multiple daily dosing with the drug produced a persistent IOP-lowering effect. Three consecutive days of Travatan treatment produced ocular hypotension of -2.0 to -2.2 mmHg (p<0.05) the following day.


CONCLUSIONS
The rebound tonometer was easy to use and accurately measured IOP in the rhesus monkey eye.
Yu
Wenhan
W
Ophthalmic Laboratories & Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.
Cao
Guiqun
G
Qiu
Jinghua
J
Liu
Xuyang
X
Ma
Jia
J
Li
Ni
N
Yu
Man
M
Yan
Naihong
N
Chen
Lei
L
Pang
Iok-Hou
IH
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D000287:Administration, Topical; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology; D002940:Circadian Rhythm / Q000187:drug effects; D003008:Cloprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D000882:Haplorhini / Q000502:physiology*; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D015203:Reproducibility of Results; D014065:Tonometry, Ocular / Q000295:instrumentation*; D000069557:Travoprost
C459092:2-methyl-1-((4-methyl-5-isoquinolinyl)sulfonyl)homopiperazine; D000959:Antihypertensive Agents; D003008:Cloprostenol; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000069557:Travoprost