Abstract
Abstract: :
Purpose We evaluated the prophylactic potential of the topical antibiotic, moxifloxacin, to prevent endophthalmitis following bacterial anterior chamber challenge in a NZW rabbit prophylaxis model.. Methods Using an IACUC approved protocol, 10 rabbits were administered one drop of 0.5% moxifloxacin every 15 minutes for one hour (5 drops) to the left eye and similarly 10 rabbits were administered saline immediately prior to bacterial inoculation. The anterior chambers of the 20 rabbits were injected with 0.025 ml of broth containing approximately 5 x 104 colony forming units of a clinical endophthalmitis isolate of Staphylococcus aureus. The moxifloxacin treated eyes were immediately administered another drop of moxifloxacin and 4 more drops were applied over the next 24 hours. The saline treated eyes were given the same treatment regimen with saline. At 24 hours post injection, the eyes were evaluated by slit-lamp in a masked fashion for the presence of iritis, hypopyon, conjunctival/scleral injection, limbal injection, corneal infiltration, blepharitis, AC cells, AC flare, red reflex, and fibrin using a scale of 0, 0.5, 1, 2, and 3 based on increasing severity. After sacrifice, the anterior and posterior chambers were cultured for bacteria. All data were analyzed with the Kruskal-Wallis test. Results The clinical scores of endophthalmitis were significantly (p=0.0001) more severe for the saline treated group (median = 21.5) than the moxifloxacin treated group (median = 0.0), which demonstrated no signs of endophthalmitis. The anterior and posterior chambers were negative for Staphylococcus aureus in the moxifloxacin group, but 50% (5/10) (mox vs saline, p=0.03) of the anterior chambers and 30% (3/10) (mox vs saline, p=0.21) of the posterior chambers were positive in the saline group. The median log transformed colony count from the anterior chamber of the saline group (1.35) was significantly higher (p=0.013) than the moxifloxacin group (zero colonies). Conclusions In our rabbit model, we demonstrated a proof of principle, that topical antibiotic therapy pre- and post intraocular bacterial challenge could prevent bacterial endophthalmitis. Surgical prophylaxis with topical moxifloxacin (0.5%) may prove to be a valuable adjunct for the prevention of endophthalmitis.
Keywords: animal model • antibiotics/antifungals/antiparasitics • endophthalmitis