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Characterization of intraocular pressure responses of the Tibetan monkey (Macaca thibetana).

Liu G, Zeng T, Yu W, Yan N, Wang H, Cai SP, Pang IH, Liu X - Mol. Vis. (2011)

Bottom Line: 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).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.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmic Laboratories & Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.

ABSTRACT

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.

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Effect of feeding time on IOP. IOP of conscious monkeys was measured at noon at two different feeding times: 11:30AM and 12:30 PM Error bars represent SEM of IOP values (n=12; both eyes of 6 animals). ***p<0.001 by paired two-tailed Student's t-test.
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f3: Effect of feeding time on IOP. IOP of conscious monkeys was measured at noon at two different feeding times: 11:30AM and 12:30 PM Error bars represent SEM of IOP values (n=12; both eyes of 6 animals). ***p<0.001 by paired two-tailed Student's t-test.

Mentions: The monkeys were routinely fed at 11:30 AM We speculated that this may contribute to the elevated IOP observed at noon. To assess this hypothesis, the feeding time was changed from 11:30 AM to 12:30 PM for one week, and IOP at noon was measured, before and then one week after the feeding time change. Changing the feeding time did affect IOP. When fed at 11:30 AM, monkeys had IOP of 29.2±2.5 mmHg (n=12) at noon. Feeding at 12:30 PM lowered the noon IOP to 25.1±1.2 mmHg (Figure 3). To be compliant with the animal care policy of the institute, for all other studies in this report, animals were fed at 11:30 AM The feeding in the afternoon was conducted at 4:30 PM, which did not seem to have the ocular hypertensive effect on the 6:00 PM IOP measurement.


Characterization of intraocular pressure responses of the Tibetan monkey (Macaca thibetana).

Liu G, Zeng T, Yu W, Yan N, Wang H, Cai SP, Pang IH, Liu X - Mol. Vis. (2011)

Effect of feeding time on IOP. IOP of conscious monkeys was measured at noon at two different feeding times: 11:30AM and 12:30 PM Error bars represent SEM of IOP values (n=12; both eyes of 6 animals). ***p<0.001 by paired two-tailed Student's t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108893&req=5

f3: Effect of feeding time on IOP. IOP of conscious monkeys was measured at noon at two different feeding times: 11:30AM and 12:30 PM Error bars represent SEM of IOP values (n=12; both eyes of 6 animals). ***p<0.001 by paired two-tailed Student's t-test.
Mentions: The monkeys were routinely fed at 11:30 AM We speculated that this may contribute to the elevated IOP observed at noon. To assess this hypothesis, the feeding time was changed from 11:30 AM to 12:30 PM for one week, and IOP at noon was measured, before and then one week after the feeding time change. Changing the feeding time did affect IOP. When fed at 11:30 AM, monkeys had IOP of 29.2±2.5 mmHg (n=12) at noon. Feeding at 12:30 PM lowered the noon IOP to 25.1±1.2 mmHg (Figure 3). To be compliant with the animal care policy of the institute, for all other studies in this report, animals were fed at 11:30 AM The feeding in the afternoon was conducted at 4:30 PM, which did not seem to have the ocular hypertensive effect on the 6:00 PM IOP measurement.

Bottom Line: 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).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.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmic Laboratories & Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.

ABSTRACT

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.

Show MeSH
Related in: MedlinePlus