Abstract
Purpose: :
This study examined the outcomes of glucocorticoids administered topically, systemically, or subconjunctivally on endotoxin-induced uveitis (EIU) in rats.
Methods: :
EIU was induced in male Lewis rats by footpad injection of lipopolysaccharide (LPS, 200 µg). Animals were randomized in four groups. The first two groups received either a single intravenous dose of 2.5 mg/kg dexamethasone phosphate (immediately after LPS inoculation) or multiple instillations of 0.1% dexamethasone (1h before and 1h, 2h and 3h after induction). The third group received a single subconjunctival dose of 1 µg methylprednisolone. A non-treated induced group was used as control of induction. Treatment effects were evaluated 24h after induction using clinical scoring, leucocyte and protein infiltration and cytokine production using multiplex analysis in aqueous humor (AH).
Results: :
Both intravenous and topical administrations of dexamethasone markedly decreased clinical signs of EIU, inflammatory cell counts, protein concentration, and levels of IL1beta, TNFalpha, IL6 and IL12 in AH. Sub-conjunctival administration of methylprednisolone also decreased the symptoms of EIU but to a lesser extent than dexamethasone.
Conclusions: :
In conclusion topical administration of dexamethasone allows for a therapeutic effect on the anterior segment of the eye in the rat EIU model, and may present a viable alternative to systemic administration of glucocorticoids.
Keywords: uveitis-clinical/animal model • cytokines/chemokines • corticosteroids