title: Betamethasone-induced ocular hypertension in rabbits.
abstract: The effect of subconjunctivally injected betamethasone on intraocular pressure (IOP) was studied in 85 albino New Zealand rabbits. IOP was measured with a Mentor Model 30 classic pneumatonograph that was manometrically calibrated to the rabbit eye. Ocular hypertension was induced by weekly subconjunctival injections of a betamethasone suspension into the left eye. In one experiment, 70 rabbits were given betamethasone for 4 weeks, while a second group of 10 rabbits received betamethasone for 11 weeks. The short-term effects of subconjunctival injections of betamethasone on IOP were also recorded in a third group of 5 rabbits. Weekly injections over 4 weeks resulted in an increase in IOP in the treated eye, which was prolonged to 11 weeks by repeated weekly injections. A sustained increase in IOP was observed in the treated eye for a period of 7 weeks. During the early hours after betamethasone injection, a transient decrease in IOP was registered in both eyes. The results show that weekly subconjunctival injections of betamethasone cause a predictable increase in IOP in the treated eye which may be suitable for testing the short- and long-term effects of antiglaucoma drugs. Evidence suggesting that endogenous glucocorticoids may play a role in the development of ocular hypertension in humans strengthens the potential value of this glaucoma model.
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Basque Country University, Vitoria, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Melena
authors.forename: J
authors.initials: J
authors.lastname: Santafé
authors.forename: J
authors.initials: J
authors.lastname: Segarra
mesh_terms: D000818:Animals; D001623:Betamethasone; D003228:Conjunctiva; D004195:Disease Models, Animal; D005938:Glucocorticoids; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects*; D009798:Ocular Hypertension / Q000139:chemically induced* / Q000503:physiopathology; D011817:Rabbits; D013997:Time Factors
chemical_list: D005938:Glucocorticoids; D001623:Betamethasone