Ocular penetration of ceftriaxone, ceftazidime, and vancomycin after subconjunctival injection in humans

Vancomycin (25 mg), ceftriaxone (125 mg), and ceftazidime (100 mg) were given by subconjunctival injection before vitrectomy to patients with uninfected eyes. Most of the patients had diabetic vitreous hemorrhage with or without traction retinal detachments, and some had rhegmatogenous retinal detachments with proliferative vitreoretinopathy. Samples of vitreous were obtained by pars plana vitrectomy at intervals from 46 minutes to 4 hours 13 minutes after the subconjunctival injection. The median vitreous concentrations of all three drugs were below the limit of detection. Vitreous concentrations of these drugs after a single subconjunctival injection are exceedingly low.