Purpose: A swine model of ocular trauma was used to determine the extent of penetration of systematically administered gentamicin and ceftazidime to the vitreous cavity of traumatized and normal eyes.
Methods: Forty-six pigs received a scleral laceration to the right eye and then underwent surgical repair. Thirty-six animals received intravenous gentamicin, and 10 pigs were given ceftazidime.
Results: The level of gentamicin in the vitreous of traumatized and nontraumatized eyes did not achieve the minimum inhibitory concentrations (MIC) for Pseudomonas and Haemophilus species despite multiple and large intravenous doses. Ceftazidime concentrations in traumatized eyes were above the minimum inhibitory concentration for these organisms.
Conclusions: Ceftazidime achieves an intravitreal concentration 33 times the minimum inhibitory concentration of Haemophilus species and twice that of Pseudomonas species in traumatized eyes after systemic administration, a finding that lends support to its use as a prophylactic agent in the management of penetrating ocular trauma. Gentamicin does not appear to enter the traumatized eye at appreciable levels after systemic administration, and, therefore, it is not recommended for use as a prophylactic agent in the management of penetrating ocular trauma.