advertisement
Abstract #10314 Published in IGR 6-1
Time-specific intraocular pressure curves in Rhesus macaques (Macaca mulatta) with laser-induced ocular hypertension
Ollivier FJ; Brooks DE; Kallberg ME; Sapp HL; Komaromy AM; Stevens GR; Dawson WW; Sherwood MB; Lambrou GNVeterinary Ophthalmology 2004; 7: 23-27
OBJECTIVE: To detect and categorize time-specific variations in daytime intraocular pressure (IOP) found in Rhesus monkeys with laser-induced ocular hypertension. PROCEDURES: Ten male monkeys with argon laser-induced ocular hypertension in one eye were anesthetized with ketamine hydrochloride, and the IOP measured in both eyes at 7 am, 7.30 am, and then hourly until 1 pm with a Tonopen trade mark XL applanation tonometer. IOP time profiles for both eyes of each animal were developed. The means ± SD of the IOPs for both eyes were calculated for the whole six-hour study period, and the values compared statistically. The difference between the lasered eye mean IOP standard deviation and the normal eye mean IOP standard deviation for each animal during the six-hour follow-up was also calculated and compared. RESULTS: Mean IOP (± SD) in the glaucoma and normal eyes for the ten animals during the six-hour study was 32.6 ± 2.5 and 14.9 ± 2.5 mmHg, respectively. IOP was significantly higher in the experimental eye than in the normal eye (p = 0.0008). Mean IOP in the lasered eye did not significantly change during the study period, whereas a slight but significant increase in IOP of the normal eye over the study period was recorded (p = 0.003). The variance in IOP in the hypertensive eyes was considerably greater than that in the untreated control eyes. From 7 am to 1 pm, the IOP declined in five eyes and increased in the other five eyes with laser-induced ocular hypertension. CONCLUSIONS: The time-specific IOP variation pattern in the daytime in the laser treated eyes is significantly greater than the variation in the normotensive eyes. This shows that in order to detect statistical differences between IOP variations induced by an IOP-reducing drug, and the exaggerated spontaneous IOP variations present in the laser-induced hypertensive eye, sufficient animals should be included in any study. Understanding the time-specific IOP variation present in a group of monkeys with laser-induced ocular hypertension is essential prior to using the model for the evaluation of IOP-reducing drugs.
Dr. F.J. Ollivier, Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
Classification:
5 Experimental glaucoma; animal models
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
