We studied the aqueous humor penetration of ofloxacin after topical, o
ral, and intravenous administration in 51 consecutive patients undergo
ing cataract surgery. Aqueous humor concentration (mean +/- SD) was 0.
53 +/- 0.35 mg/l when ofloxacin 0.3% eyedrops were instilled topically
six times, one drop every three hours, until 90 minutes preoperativel
y, and 0.63 +/- 0.29 mg/l (P = .45) when two additional instillations
were made, one drop every 30 minutes, until 30 minutes before aqueous
humor aspiration. Aqueous humor concentration two hours after a single
200-mg oral dose (0.38 +/- 0.15 mg/1) was significantly lower (P = .0
48) than that 12 hours after the same oral dose (0.58 +/- 0.24 mg/1).
Two hours following an intravenous infusion of 200 mg of ofloxacin, aq
ueous humor concentration was 0.33 +/- 0.19 mg/l. Our results suggest
that therapeutic levels above the minimum inhibitory concentration for
many bacteria cultured in endophthalmitis can be achieved in aqueous
humor after either topical or oral administration, which indicates tha
t this antibiotic passes easily through the corneal and the blood aque
ous barriers.