Bacterial keratitis is a serious and potentially sight-threatening condition, which can cause corneal scarring and opacification and, occasionally, perforation. Traditionally, treatment has involved frequent dosing by instillation and/or injection of compounded, fortified antibacterial solutions or a combination of commercially available topical antibacterial agents. Of late, fourth-generation fluoroquinolones have become the standard of care for eyes with small or peripheral corneal infiltrates, whereas fortified antibiotics remain the treatment of choice for more severe ulcers or when the risk of permanent vision loss is high.

Jai Parekh, MD, William Trattler, MD, and I recently published the results of a retrospective, postmarketing surveillance study of the safety of besifloxacin ophthalmic suspension 0.6% (Besivance; Bausch + Lomb) for the treatment of bacterial keratitis.¹ Our goal was to assess the safety of this treatment approach. The research was conducted at 10 clinical centers across the United States. It included 142 patients who underwent treatment in one or both eyes with besifloxacin and, for perspective, 85 patients who instead received moxifloxacin ophthalmic solution 0.5% (Vigamox; Alcon), an older medication.

Primarily, we sought to identify the types and rates of adverse events reported during treatment with besifloxacin. We also looked at the development of corneal scarring and neovascularization, patients' final visual acuities, how long they experienced pain before and after treatment, and measured bacterial eradication based on clinical appearances.

Our findings were consistent with those reported for larger, prospective, controlled studies of besifloxacin for the treatment of bacterial conjunctivitis.^2-5 In our study, the difference in the frequency of adverse events was low and not significant between the besifloxacin and moxifloxacin groups, and both drugs were associated with high rates of bacterial eradication
(> 90%).

Although our findings suggest that besifloxacin is efficacious and safe for the treatment of bacterial keratitis, a major limitation of our study is its retrospective nature. That being said, most clinically relevant adverse events would likely have been reported. A future prospective clinical trial is warranted to confirm our findings and to isolate the therapeutic contribution of besifloxacin, because patients in both treatment groups received additional antibiotics.n

Barry A. Schechter, MD
• director, Department of Cornea and External Diseases, Florida Eye Microsurgical Institute, Boynton Beach, Florida
• (561) 737-5500; baschechter@gmail.com
• financial disclosure: consultant to Abbott Medical Optics, Bausch + Lomb, and a member of the speakers board for Omeros

1.  Schechter BA, Parekh JG, Trattler W. Besifloxacin ophthalmic suspension 0.6% in the treatment of bacterial keratitis: a retrospective safety surveillance study [published online ahead of print November 19, 2014]. J Ocul Pharmacol Ther. doi: 10.1089/jop.2014.0039.

2.  Karpecki P, Depaolis M, Hunter JA, et al. Besifloxacin ophthalmic suspension 0.6% in patients with bacterial conjunctivitis: a multicenter, prospective, randomized, double-masked, vehicle-controlled, 5-day efficacy and safety study. Clin Ther. 2009;31(3):514-526.

3.  McDonald MB, Protzko EE, Brunner LS, et al. Efficacy and safety of besifloxacin ophthalmic suspension 0.6% compared with moxifloxacin ophthalmic solution 0.5% for treating bacterial conjunctivitis. Ophthalmology. 2009;116(9):1615-1623.

4.  Tepedino ME, Heller WH, Usner DW, et al. Phase III efficacy and safety study of besifloxacin ophthalmic suspension 0.6% in the treatment of bacterial conjunctivitis. Curr Med Res Opin. 2009;25(5):1159-1169.

5.  DeLeon J, Silverstein BE, Allair C, et al. Besifloxacin ophthalmic suspension 0.6% administered twice daily for 3 days in the treatment of bacterial conjunctivitis in adults and children. Clin Drug Investig. 2012;32(5):303-317.