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Abstract #19598 Published in IGR 9-3
Effect of 15-keto latanoprost on intraocular pressure and aqueous humor dynamics in monkey eyes
Wang R-F; Gagliuso DJ; Mittag TW; Podos SMInvestigative Ophthalmology and Visual Science 2007; 48: 4143-4147
PURPOSE: To compare the ocular hypotensive effects of 15-keto latanoprost (KL) with the commercial preparation of latanoprost (Xalatan; Pfizer, New York, NY) in monkey eyes with laser-induced unilateral glaucoma and to evaluate the effects of topical 0.005% KL on aqueous humor dynamics in normal monkey eyes. METHODS: Intraocular pressure (IOP) was measured hourly for 6 hours beginning at 9:30 AM on day 1 (untreated baseline); day 2 (vehicle only); and treatment days 1, 3, and 5 (topical, 30 μL of study drug) in the glaucomatous eyes of four to eight monkeys with unilateral laser-induced glaucoma. KL concentrations of 0.0001%, 0.001%, and 0.01% and latanoprost at 0.005% were studied separately, with a minimum washout period of 2 weeks between studies. Tonographic outflow facility (C) and fluorophotometric aqueous humor flow rates (F) were measured in nine normal monkeys before and after a single topical dose of 0.005% KL in one eye, with a vehicle-only control in the fellow eye. RESULTS: When applied once daily to glaucomatous monkey eyes, all three concentrations of KL and a 0.005% concentration of latanoprost produced significant (P < 0.05) reductions in IOP, with the maximum reduction on treatment day 5, regardless of the drug or concentration studied. The maximum reduction (P < 0.001) from vehicle-only baseline IOP was (mean ± SEM) 3.0 ± 0.3 mmHg (9%) for 0.0001% KL, 7.6 ± 0.6 mmHg (23%) for 0.001% KL, 6.3 ± 0.4 mmHg (18%) for 0.01% KL, and 6.6 ± 0.6 mmHg (20%) for 0.005% latanoprost. After application of a single dose of 0.005% KL in nine normal monkey eyes, neither C nor F was altered (P > 0.80) when compared with untreated baseline values or vehicle-treated control eyes. CONCLUSIONS: The reduction in IOP produced by 0.001% KL was equivalent to, and at some measured time points, greater than the effect produced by 0.005% latanoprost. The IOP reduction by KL in normal monkeys appeared to have no effect on aqueous humor production or tonographic outflow facility and may thus indicate a drug-induced increase in uveoscleral outflow.
Classification:
11.4 Prostaglandins (Part of: 11 Medical treatment)
5.2 Primates (Part of: 5 Experimental glaucoma; animal models)
2.6.2.2 Uveoscleral (Part of: 2 Anatomical structures in glaucoma > 2.6 Aqueous humor dynamics > 2.6.2 Outflow)
