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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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Related in: MedlinePlus

Circadian IOP fluctuation of conscious Tibetan monkeys. IOP was measured by the TonoVet® rebound tonometer at the indicated times of the day. Data of two studies conducted three days apart on the same animals are presented together: the first study monitored IOP from 9 AM to 9 PM; the second, from 9 PM to 9 AM Symbols represent mean±SEM (n=12; both eyes of 6 animals).
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f2: Circadian IOP fluctuation of conscious Tibetan monkeys. IOP was measured by the TonoVet® rebound tonometer at the indicated times of the day. Data of two studies conducted three days apart on the same animals are presented together: the first study monitored IOP from 9 AM to 9 PM; the second, from 9 PM to 9 AM Symbols represent mean±SEM (n=12; both eyes of 6 animals).

Mentions: Circadian IOP fluctuation was clearly detected in the conscious Tibetan monkeys. In this study, measurements of IOP were conducted at 9 AM, noon, 3 PM, 6 PM (immediately before lights off), and 9 PM in the same day. Three days later, IOP of the same animals were monitored again at 9 PM, midnight, 3 AM, 6 AM (immediately before lights on), and 9 AM By combining data from these two studies, a 24-h IOP profile was obtained. As seen in Figure 2, the IOP values of Tibetan monkeys were generally higher during the day and lower at night. They were between 20 and 24 mmHg at most time points. However, a distinct elevation of IOP was observed at noon (29.3±0.9 mmHg, mean±SEM, n=12). The lowest IOP reading (19.6±0.8 mmHg) occurred at 3:00 AM (Figure 2).


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)

Circadian IOP fluctuation of conscious Tibetan monkeys. IOP was measured by the TonoVet® rebound tonometer at the indicated times of the day. Data of two studies conducted three days apart on the same animals are presented together: the first study monitored IOP from 9 AM to 9 PM; the second, from 9 PM to 9 AM Symbols represent mean±SEM (n=12; both eyes of 6 animals).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Circadian IOP fluctuation of conscious Tibetan monkeys. IOP was measured by the TonoVet® rebound tonometer at the indicated times of the day. Data of two studies conducted three days apart on the same animals are presented together: the first study monitored IOP from 9 AM to 9 PM; the second, from 9 PM to 9 AM Symbols represent mean±SEM (n=12; both eyes of 6 animals).
Mentions: Circadian IOP fluctuation was clearly detected in the conscious Tibetan monkeys. In this study, measurements of IOP were conducted at 9 AM, noon, 3 PM, 6 PM (immediately before lights off), and 9 PM in the same day. Three days later, IOP of the same animals were monitored again at 9 PM, midnight, 3 AM, 6 AM (immediately before lights on), and 9 AM By combining data from these two studies, a 24-h IOP profile was obtained. As seen in Figure 2, the IOP values of Tibetan monkeys were generally higher during the day and lower at night. They were between 20 and 24 mmHg at most time points. However, a distinct elevation of IOP was observed at noon (29.3±0.9 mmHg, mean±SEM, n=12). The lowest IOP reading (19.6±0.8 mmHg) occurred at 3:00 AM (Figure 2).

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