Comparative treatment of experimental Staphylococcus epidermidis endophthalmitis
T. A. Meredith, H. E. Aguilar, M. J. Miller, S. K. Gardner, A. Trabelsi and L. A. Wilson
Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322.
We created experimental Staphylococcus epidermidis endophthalmitis of
moderate severity in the aphakic rabbit eye by injecting 100,000 organisms
of a standardized laboratory strain (ATCC 155) into the mid-vitreous
cavity. This model of endophthalmitis self-sterilizes in about 4 days, but
inflammatory signs continue to increase 5 to 7 days after the initial
bacterial inoculum. Control eyes were compared with eyes treated with five
different strategies 24 hours after bacterial inoculation: intravitreal
cefazolin sodium, intravitreal cefazolin plus intramuscular corticosteroid,
vitrectomy plus intravitreal antibiotics, vitrectomy plus intravitreal
antibiotics and intramuscular corticosteroids, and vitrectomy plus
intravitreal antibiotics and corticosteroids. Quantitative grading of
inflammation and media clarity were compared at the end of weeks 1, 2, and
3 after treatment. At week 1, eyes treated with vitrectomy had
significantly lower inflammatory scores; those treated with corticosteroids
had significantly lower scores than those without. The two effects were
independent. The best results were observed with treatment consisting of
vitrectomy, intraocular antibiotics, and corticosteroids. This strategy
also produced significantly more eyes with clear media at the end of week 3
than treatment with intravitreal antibiotics alone.
