To the Editor.
—Martin and associates1 reported vitreous cefazolin levels in a rabbit model of experimental endophthalmitis. These authors used heat-killed Staphylococcus epidermidis organisms to induce intraocular inflammation and then measured the penetration of systemically administered cefazolin. Meredith and associates2 reported further rabbit model studies of S epidermidis endophthalmitis and observed no significant difference in inflammatory scores between the placebo-treated group and the group treated with 2.25 mg of intravitreal cefazolin. However, there were more eyes with clear media at the end of week 3 in the group treated with vitrectomy, 2.25 mg of intravitreal cefazolin, and either systemic or intravitreal corticosteroids.Although cefazolin does penetrate the eye from systemic administration and also may be used intravitreally, it is important to recognize that frequent resistance will occur among organisms commonly encountered in clinical endophthalmitis. Davis and associates3 reported a series of cases of coagulase-negative staphylococci with a 19%
Flynn HW, Pulido JS, Pflugfelder SC, Davis JL, Culbertson WW, Roussel TJ, Miller D. Endophthalmitis Therapy: Changing Antibiotic Sensitivity Patterns and Current Therapeutic Recommendations. Arch Ophthalmol. 1991;109(2):175-176. doi:10.1001/archopht.1991.01080020021012