Objectives: To investigate the intracorneal, aqueous, and vitreous penetration of ofloxacin, and to assess the concentration of the drug after topical administration alone and after combined topical and oral administration.
Methods: Twenty consecutive patients undergoing penetrating keratoplasty with vitrectomy for bullous keratopathy received 2 drops of 0.3% ofloxacin every 30 minutes starting 4 hours before surgery. Group A (10 patients) received topical therapy alone. Group B (10 patients) received an additional 3 doses of oral ofloxacin, 400 mg, every 12 hours starting 26 hours before surgery. Aqueous humor, vitreous humor, and corneal specimens were analyzed for ofloxacin levels.
Results: For group A, the mean intracorneal ofloxacin level was 4.51 micrograms/mL (range, 0.58-8.77 micrograms/mL; 10 specimens), the mean aqueous humor level was 1.34 micrograms/mL (range, 0.07-4.98 micrograms/mL; 8 specimens), and the mean vitreous humor level was 0.37 micrograms/mL (range, 0.05-0.90 micrograms/mL; 8 specimens). For group B, the mean intracorneal ofloxacin level was 8.59 micrograms/mL (range, 1.18-23.24 micrograms/mL; 10 specimens), the mean aqueous humor level was 2.77 micrograms/mL (range, 0.25-5.80 micrograms/mL; 10 specimens), and the mean vitreous humor level was 2.55 micrograms/mL (range, 0.28-4.97 micrograms/mL; 9 specimens).
Conclusions: Topically applied ofloxacin achieves therapeutic levels in the cornea and aqueous. Mean levels achievable are well above the 90% minimal inhibitory concentration (MIC90) for the majority of bacteria responsible for endophthalmitis and corneal ulceration. The addition of oral ofloxacin to topical therapy increased vitreous penetration 7-fold in this assay trial.