Intravitreal cephalothin in experimental staphylococcal endophthalmitis

Intravitreal cephalothin was used to treat experimentally induced bacterial endophthalmitis in rabbit eyes. A dose of 2 mg and less was apparently nontoxic to all intraocular structures. Thirty-two hours after injection of a 2 mg dose, the level remaining in the vitreous was above the minimal inhibitory concentration for most susceptible organisms. Treatment of experimentally induced staphylococcal infections of the vitreous was successful with early intravitreal injection. When therapy was delayed, vitreous bands and posterior lens cataracts developed. Eyes of control animals receiving intramuscular and subconjunctival injections of cephalothin all progressed to phthisis bulbi.