Clearance of fluorescein incorporated into microspheres from the cornea and aqueous after subconjunctival injection.

The clearance of sodium fluorescein from the cornea and aqueous humor of albino rabbits was quantitated after subconjunctival injection of fluorescein entrapped in lactide/glycolide (group 1) and lactide (group 2) microspheres. Seven hours after injection, approximately equal concentrations of fluorescein were measured in both groups in the cornea and aqueous. Fluorescein concentrations in the cornea were more than three times those found in the aqueous. Fluorescein concentrations in both groups decreased at 22 hours, and remained constant at 46 hours. Corneal fluorescein levels in group 2 were slightly higher than in group 1 at 22 and 46 hours. All eyes showed conjunctival inflammatory reaction at the injection sites after 6 days. One eye showed conjunctival necrosis at the injection site after 13 days.