OXACILLIN FOR BACTERIAL ENDOPHTHALMITIS - SUB-CONJUNCTIVAL, INTRAVENOUS, BOTH, OR NEITHER

  • 1 January 1980
    • journal article
    • research article
    • Vol. 19  (11) , 1348-1354
Abstract
The intraocular concentrations of oxacillin given by continuous i.v. infusion, subconjunctival injection, or combined therapy in a rabbit model of Staphylococcus aureus endophthalmitis. At equilibrium during i.v. infusion, concentrations in the aqueous humor, cornea, and choroid-retina were 25-30% of the serum level; in contrast, vitreous levels were only 2% of the serum concentration. Subconjunctival injection produced extremely high levels in the cornea and aqueous and moderate concentrations in the choroid-retina; vitreous penetration remained poor (< 1 .mu.g/ml). Combined therapy offered little advantage in terms of concentrations in the aqueous or cornea and had a modest effect on levels in the choroid-retina. Vitreous concentrations showed a striking relation to serum levels with all regimens, including subconjunctival ones; although this could have been fortuitous, it suggests an important role for the hematogenous route in this model. Only those modes of delivery producing serum concentrations greater than 50 .mu.g/ml consistently resulted in vitreous levels greater than 0.4 .mu.g/ml. The optimal therapy of bacterial endophthalmitis may require direct intravitreal injection of antibiotic.