John Bartell

Safety and efficacy of moxifloxacin-dexamethasone eyedrops as treatment for bacterial ocular infection associated with bacterial blepharitis.

IntroductionTreatments that offer two medications in a fixed combination have the potential to offer efficacious and safe treatment with advantages such as a regimen that is simpler than administering two separate solutions. This study evaluated the safety and efficacy of fixed-combination versus concomitant moxifloxacin 0.5% and dexamethasone 0.1% ocular solutions for the treatment of bacterial ocular inflammation and infection.MethodsThe clinical study design was a randomized, double-masked, active-controlled, parallel-group trial of 102 subjects with bacterial blepharitis in which two patients also had bacterial conjunctivitis. All subjects received two bottles of study medication: either a fixed combination of moxifloxacin 0.5%/dexamethasone 0.1% ophthalmic solution and placebo eye drops (fixed-dose group), or moxifloxacin 0.5% ophthalmic solution and dexamethasone 0.1% (concomitant group). One drop of each study medication was instilled bilaterally four times per day for 7 days. Clinical resolution, signs, symptoms, and safety were assessed. Microbiological specimens were collected from the eyelid margin and conjunctivae of each eye from each patient at the time of enrollment and at the exit visit.ResultsClinical resolution occurred similarly in both groups (81.6% of eyes, fixed-dose group; 82.3% of eyes, concomitant group). Moreover, the microbiological efficacy of the treatment was also similar for both the fixed-dose group (84%) and the concomitant group (83%). Ocular symptoms and signs improved over time, with no significant differences between groups after 7 days of treatment, except the fixed-dose group had significantly more eyes with clinical resolution in eyelid erythema (100%, n = 98/98, fixed-dose group; 92.7%, n = 89/96, concomitant group; P = 0.0194) and eyelid scaling/crusting (98%, n = 96/98, fixed-dose group; 89.6%; n = 86/96 eyes, concomitant group; P = 0.0337). Both regimens were safe and well tolerated.ConclusionThe fixed-dose combination of moxifloxacin, 0.5% and dexamethasone, 0.1% was therapeutically equivalent and as well tolerated as the concomitant dosage.

Microbiological efficacy of a new ophthalmic formulation of moxifloxacin dosed twice-daily for bacterial conjunctivitis

IntroductionAn alternative formulation of 0.5% moxifloxacin ophthalmic solution (Moxeza®, MOXI-AF, Alcon Laboratories, Inc., Fort Worth, TX, USA) containing xanthan gum to prolong retention on the eye has been developed. MOXI-AF was designed to optimize the treatment regimen for bacterial conjunctivitis for the convenience of the patient with twice-daily dosing.MethodsA safety and efficacy clinical study was conducted as a multicenter, vehiclecontrolled, randomized, double-masked, parallel group study in clinically diagnosed bacterial conjunctivitis patients aged >28 days. MOXI-AF or its vehicle was dosed one drop twice-daily for 3 days. Microbiological specimens were obtained from affected eyes on day 1, prior to the initial dose, and on day 4 after 3 days of dosing, and processed using routine clinical microbiology laboratory methods. All recovered bacteria were identified to the species level.ResultsThis paper reports on the microbiological success rate, a secondary efficacy variable in the trial. All patients (1180) were randomized to treatment. Patient age ranged from 30 days to 92 years. The microbiological success rate for patients treated topically with MOXI-AF twice-daily for 3 days was 74.5%, compared with 56.0% of patients treated with its vehicle control (P<0.0001). MOXI-AF was also statistically more effective than vehicle in eradicating the three principle conjunctivitis pathogens, Haemophilus influenzae (98.5% vs. 59.6%, respectively), Streptococcus pneumoniae (86.4% vs. 50.0%, respectively), and Staphylococcus aureus (94.1% vs. 80.0%, respectively) (P<0.001).ConclusionThe xanthan gum-based 0.5% moxifloxacin ophthalmic formulation, MOXI-AF, provides effective eradication of the three principle causative pathogens of bacterial conjunctivitis across all age groups when dosed twice-daily for 3 days.

A Highly Virulent Staphylococcus aureus: Rabbit Anterior Chamber Infection, Characterization, and Genetic Analysis

PURPOSE To describe and characterize a Staphylococcus aureus strain with unique virulence that overcomes host defenses of the rabbit anterior chamber and mimics clinical cases of postcataract surgery endophthalmitis. METHODS Nine isolates of S. aureus were tested to determine their viability in the rabbit anterior chamber. Growth of UMCR1 in the anterior chamber was established and expressed as log colony-forming units per milliliter of aqueous humor. Pathologic changes produced by UMCR1 were documented by photographs, slit lamp examination, histopathologic analysis, and quantification of neutrophils. UMCR1 was characterized by antibiotic susceptibility, biochemical tests, ribotyping, genome restriction mapping, and multilocus sequence typing (MLST). RESULTS UMCR1 was the only S. aureus strain that grew within the anterior chamber, reaching log 6.97 ± 0.18 CFU/mL by 16 hours after infection. Pathologic changes included conjunctival injection, chemosis, corneal edema, severe iritis, fibrin accumulation, and a 193-fold increase in neutrophils by 16 hours after infection. UMCR1 was only resistant to sulfamethoxazole and, like other S. aureus isolates, polymyxin B. UMCR1 also had biochemical reactions and a ribotype pattern typical of S. aureus. The genomic reconstruction analysis of UMCR1 was most similar to strains MW2 and MSSA476. MLST revealed a 1 in 3198 nucleotide difference between UMCR1 and strains MW2 and MSSA476. CONCLUSIONS This study describes a unique S. aureus strain that overcomes host defenses and replicates in the anterior chamber. The survival and growth of this organism could be used for studies of S. aureus pathogenesis, host defenses, and effectiveness of antibiotics within the anterior chamber.

Antimicrobial Efficacy of Multipurpose Disinfecting Solutions in the Presence of Contact Lenses and Lens Cases.

Objective: The aim of this study was to use antimicrobial efficacy endpoint methodology to determine compatibility of multipurpose disinfecting solutions (MPSs), lens cases, and hydrogel lenses for disinfection (AEEMC) against International Organization for Standardization (ISO)–specified microorganisms and clinical ocular isolates of Stenotrophomonas maltophilia. Methods: Six MPSs (PQ/Aldox 1, 2, and 3; PQ/Alexidine; PQ/PHMB; and PHMB) were challenged against ISO-specified microorganisms and S. maltophilia using the AEEMC test. AEEMC tests were performed with and without balafilcon A, etafilcon A, and senofilcon A lenses in lens cases with organic soil. Exposure times included disinfection time (DT) and 24 hr. Additionally, all six MPSs were challenged with two strains of S. maltophilia, based on the ISO Stand-alone test. Results: The efficacy against bacteria for PQ/Aldox and PQ/Alexidine MPSs was not diminished by the presence of lenses. The efficacy of PQ/PHMB and PHMB MPSs against Serratia marcescens was significantly reduced compared with the no-lens control at DT for at least one lens type. The PHMB MPS with lenses present also demonstrated reduced efficacy against Staphylococcus aureus at DT versus the control. PQ/Aldox MPSs retained activity against Fusarium solani with lenses present; however, all other test MPSs demonstrated reduced F. solani efficacy at DT with lenses present. With lenses, all MPSs showed reduced efficacy against Candida albicans. Conclusions: AEEMC antimicrobial efficacy test results vary based on challenge microorganism, contact lenses, and MPS biocide systems. This study highlights the importance of evaluating MPSs for compatibility with lenses and lens cases.