INTRACORNEAL, AQUEOUS-HUMOR, AND VITREOUS-HUMOR PENETRATION OF TOPICAL AND ORAL OFLOXACIN

Objectives: To investigate the intracorneal, aqueous, and vitreous pen etration of ofloxacin, and to assess the concentration of the drug aft er topical administration alone and after combined topical and oral ad ministration. Methods: Twenty consecutive patients undergoing penetrat ing keratoplasty with vitrectomy for bullous keratopathy received 2 dr ops of 0.3% ofloxacin every 30 minutes starting 4 hours before surgery . Group A (10 patients) received topical therapy alone. Group B (10 pa tients) received an additional 3 doses of oral ofloxacin, 400 mg, ever y 12 hours starting 26 hours before surgery. Aqueous humor, vitreous h umor, and corneal specimens were analyzed for ofloxacin levels. Result s: For group A, the mean intracorneal ofloxacin level was 4.51 mu g/mL (range, 0.58-8.77 mu g/mL; 10 specimens), the mean aqueous humor leve l was 1.34 mu g/mL (range, 0.07-4.98 mu g/mL; 8 specimens), and the me an vitreous humor level was 0.37 mu g/mL (range, 0.05-0.90 mu g/mL; 8 specimens). For group B, the mean intracorneal ofloxacin level was 8.5 9 mu g/mL (range, 1.18-23.24 mu g/mL; 10 Specimens), the mean aqueous humor level was 2.77 mu g/mL (range, 0.25-5.80 mu g/mL; 10 specimens), and the mean vitreous humor level was 2.55 mu g/mL (range, 0.28-4.97 mu g/mL; 9 specimens). Conclusions: Topically applied ofloxacin achiev es therapeutic levels in the cornea and aqueous. Mean levels achievabl e are well above the 90% minimal inhibitory concentration (MIG,,) for the majority of bacteria responsible for endophthalmitis and corneal u lceration. The addition of oral ofloxacin to topical therapy increased vitreous penetration 7-fold in this assay trial.