Abstract
Abstract: :
Purpose: To compare the efficacy of topical dexamethasone and loteprednol on experimental uveitis in an animal model. Methods: Uveitis was induced by the sub–plantar injection of endotoxin (200 µg in 0.1 ml saline) in the right hind paw of female Lewis rodents (5/group). Test compounds were prepared in an ophthalmic suspension vehicle. Test compound or vehicle (5 µl) were administered topically to each eye of the experimental animals at the time of endotoxin injection and again 4 hours later. Twenty–four (24) hours after endotoxin injection, the animals were sacrificed and total ocular neutrophil (PMN) content was assessed indirectly by determination of myeloperoxidase (MPO) activity. Ocular PMN content in each drug–treated group was then compared with that observed in the vehicle–treated group using Dunnett's t–test. Results: Dexamethasone 0.1% and 0.033% produced a significant (P < 0.01) decrease in MPO activity. Dexamethasone, at concentrations of 0.01%, 0.033% and 0.1%, inhibited ocular MPO activity by 21%, 81% and 95%, respectively. Loteprednol, at concentrations of 0.3%, 1.0% and 3.0%, produced inhibitions of 36%, 47% and 25%, respectively, using this indirect measure of PMN influx. Conclusions: Topical dexamethasone 0.1% was significantly more effective at inhibiting ocular neutrophil influx in this experimental model of uveitis than was loteprednol even at concentrations up to 3.0%.
Keywords: inflammation • uveitis-clinical/animal model • anterior chamber