Intracorneal, aqueous humor, and vitreous humor penetration of topical and oral ofloxacin.

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.