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Background: Mycobacterium chelonae and Mycobacterium fortuitum are the 2 most commonly implicated species of nontuberculous myoobacteria in cases of bacterial keratitis. Objectives: This article summarizes available data on the in vitro antibacterial activity against M chelonae or M fortuitum of 2 agents—amikacin and clarithromycin—that have been used in the treatment of bacterial keratitis. In addition, the article reviews the in vitro activity of 5 commercially available topical ocular fluoro-quinolones (in order of availability, ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin, and moxifloxacin) that may have potential in the surgical prophylaxis and treatment of keratitis caused by M chelonae or M fortuitum . Methods: A search of the English-language literature indexed on the MEDLINE, Life Sciences, EMBASE, BIOSIS, and Pharmaprojects databases from 1966 to October 7, 2003, was conducted using the terms Mycobacterium chelonae, Mycobacterium fortuitum, bacterial keratitis, topical antibiotic therapy, ocular infection-mycobacteria , and LASIK infections . Data on the minimum concentrations at which 90% of isolates were inhibited (MIC 90 s) were reviewed and compared. Results: In the literature reviewed, the MIC 90 against M fortuitum was from 1 to 16 μg/mL for amikacin, from ≤2 to ≥8 μg/mL for clarithromycin, from 0.1 to 1 μg/mL for ciprofloxacin, from 0.5 to 3.13 μg/mL for ofloxacin, and ≤2 μg/mL for levofloxacin. The results were similar against M chelonae . The fourth-generation fluoroquinolones—gatifloxacin and moxifloxacin—had similar MIC 90 s against M fortuitum (both, 0.2 to 1 μg/mL); however, moxifloxacin had greater activity than gatifloxacin against M chelonae (minimum inhibitory concentration range: moxifloxacin, ≤1 to 1.6 μg/mL; gatifloxacin, 3.2 to 6.25 μg/mL). Conclusions: Topical fluoroquinolones may be beneficial for ocular surgical prophylaxis and for the treatment of keratitis caused by M chelonae or M fortuitum . Based on their reported MIC 90 s, none of the antibacterials reviewed had greater in vitro activity than moxifloxacin. In addition, moxifloxacin had greater in vitro activity than gatifloxacin against M chelonae , one of the predominant nontuberculous mycobacterial species involved in bacterial keratitis. Pending the conduct of controlled clinical studies, these findings suggest that moxifloxacin may have utility in the prevention and treatment of atypical mycobacterial keratitis.

Intraocular inflammation is typically treated with a combination of anti-inflammatory and anti-infective drugs. Tobramycin-dexamethasone (TD) has not been associated with any serious adverse events, indicating good tolerability.The aims of this study were the following: (1) to demonstrate noninferiority of TD compared with dexamethasone-neomycin-polymyxin (DNP) in terms of anti-inflammatory efficacy, (2) to compare the anti-inflammatory efficacy of TD and DNP with that of a "placebo" control (antibiotic without anti-inflammatory agent), and (3) to provide additional safety data on TD.This prospective, double-masked, parallel-group study was conducted at 22 ophthalmology clinics across Europe and Brazil. Patients aged18 years undergoing cataract surgery were randomly assigned, in a 2:2:1 ratio, to receive tobramycin 3 mg/mL plus dexamethasone 1 mg/mL, dexamethasone 1 mg/mL plus neomycin sulfate 3500 IU/mL plus polymyxin B sulfate 6000 IU/mL, or neomycin sulfate 3500 IU/mL plus polymyxin B sulfate 7500 IU/mL plus gramicidin 20 microg/mL. All treatments were given as 1 drop instilled in the operated eye q.i.d. for 21 days. The primary efficacy end point, intraocular inflammation (determined using the sum of scores on anterior chamber cells and aqueous flare), was assessed at days 3, 8, 14, and 21 after surgery.A total of 271 patients were enrolled (158 women, 113 men; age range 42-90 years) (TD, 104 patients; DNP, 110 patients; and neomycin-polymyxin-gramicidin [NPG], 57 patients). Intraocular inflammation was similar in the TD and DNP groups at all time points. At days 8, 14, and 21, inflammation scores were significantly lower with TD than with NPG (all, P0.05). At day 8, the inflammation score was significantly lower with DNP than with NPG (P0.05). A greater number of patients receiving NPG experienced treatment-related ocular allergic reactions compared with patients receiving TD (P0.05). One patient receiving TD (1.0%) and 5 given NPG (9.0%) were withdrawn due to ocular allergic reactions. None of the patients experienced an increase in intraocular pressureor =10 mm Hg from baseline.In this study of patients undergoing cataract surgery combination therapy with TD was noninferior to DNP and was well tolerated.