Purpose: To determine the penetration of moxifloxacin 0.5% in the human aqueous and vitreous when delivered by a presoaked collagen shield.
Setting: University-based clinical practice.
Methods: Moxifloxacin 0.5% was administered before vitrectomy surgery in 10 patients using a 24-hour dissolvable cross-linked corneal collagen shield delivery device. Aqueous and vitreous samples were obtained after the shield was placed for 4 hours in the first 5 patients and for 24 hours in the second 5 patients. Assays were performed using high-performance liquid chromatography.
Results: Delivery of moxifloxacin via a collagen shield revealed a mean aqueous concentration of 0.30 microg/mL +/- 0.17 (SD) 4 hours after placement (n = 5). Vitreous levels at 4 hours and aqueous and vitreous levels at 24 hours were negligible using this route of administration. Peak aqueous moxifloxacin levels occurred soon after shield placement. This is when high concentrations of moxifloxacin are most needed to clear the aqueous of bacteria. The minimum inhibitory concentration at which 90% of the isolates were inhibited for organisms commonly responsible for endophthalmitis was exceeded in the 4-hour aqueous group. Negligible concentrations were detected at 24 hours.
Conclusions: Although aqueous moxifloxacin levels achieved through the use of a collagen shield delivery device are lower than via topical drops, there are several advantages to this route of delivery that make it appealing in the immediate postoperative period. Future studies will be needed to define precisely the role of fourth-generation fluoroquinolones and presoaked collagen shields in the prophylaxis or management of intraocular infections.