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Updated: Jun 1, 2026
A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice
Published on: October 5, 2018
Characterization of intraocular pressure responses of the Tibetan monkey (Macaca thibetana)
1Ophthalmic Laboratories & Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
Purpose:
To characterize the effects of circadian rhythm, feeding time, age, general anesthesia, and ocular hypotensive compounds on intraocular pressure (IOP) of the Tibetan monkey (Macaca thibetana).
Methods:
Tibetan monkeys were trained for IOP measurement with the TonoVet® rebound tonometer without sedation or anesthesia. Their circadian IOP fluctuation was monitored every 3 h. Effects of changing the feeding time, general anesthesia, age (2-3 year-old versus 8-15 year-old animals), and various pharmacological agents, such as travoprost, timolol, naphazoline and spiradoline, on IOP were also evaluated.
Results:
After behavioral training, conscious Tibetan monkeys were receptive to IOP measurement. The lowest and highest IOP values in a circadian cycle were recorded at 3:00 AM (19.8±0.4 mmHg, mean±SEM, n=12) and noon (29.3±0.9 mmHg), respectively. Changing the feeding time from 11:30 AM to 12:30 PM lowered the noon IOP to 25.1±1.2 mmHg. General anesthesia lowered IOP in these monkeys, while IOP of young and mature animals were similar. Three hours after topical ocular administration, travoprost reduced IOP by 5.2±0.6 mmHg (n=6, p<0.001), and timolol reduced IOP by 2.8±0.7 mmHg (p<0.05). Naphazoline and spiradoline lowered IOP by 4.8 mmHg and 2.5 mmHg (both p<0.001), respectively, 2 h after drug administration.
Conclusions:
The circadian IOP fluctuation in conscious Tibetan monkeys and their responses to travoprost, timolol, and other experimental conditions are similar to other primates. These monkeys appear to be a suitable model for glaucoma research.
