Periocular injection of corticosteroids: an experimental evaluation of its role in the treatment of corneal inflammation.

The present experiments demonstrate that subconjunctivally injected corticosteroids are less effective in suppressing corneal inflammation than are topically instilled corticosteroids. Topical administration of 6.5 mg of prednisolone acetate over a 30-hour period reduced corneal inflammatory activity by 52%. Subconjunctival injection of 50 mg of the same steroid, also given over a 30-hour period, yielded a 15% reduction in corneal inflammation. A fourfold increase (200 mg) in the quantity of prednisolone acetate injected subconjunctivally resulted in a nonsignificant (P less than .05) increment (24%) in anti-inflammatory effect. Dexamethasone sodium phosphate achieved a 30% reduction in corneal inflammation, the maximum effect observed after subconjunctival administration. The data suggest that different modes of corneal penetration are involved after drug delivery via the two routes. Concurrent administration of corticosteroids by the topical and subconjunctival routes seemingly produced an additive anti-inflammatory effect.