A Preliminary Study to Treat Severe Endophthalmitis via a Foldable Capsular Vitreous Body with Sustained Levofloxacin Release in Rabbits

Abstract

We investigated whether the foldable capsular vitreous body (FCVB) could release levofloxacin sustainably in vitro and inhibit endophthalmitis in rabbit models. Approximately 1.0 mL levofloxacin (625 μg/mL) was injected into the capsule of nine FCVBS. The levofloxacin release value was determined in the modified franz diffusion cells over time. In the in vivo study, all right eyes of 45 rabbits were infected with Staphylococcus epidermidis AND were divided randomly into three groups at 24 hours after infection: FCVB plus levofloxacin (n = 15), silicone oil plus subconjunctival levofloxacin (n = 15), and an untreated group (n = 15) during a 30-day observation time. Levofloxacin concentrations in the aqueous humor were detected, and therapeutic efficacy was evaluated with clinical evaluation, bacterial counts, cytokine profiles, and histopathology. The FCVB released levofloxacin ranging from 9 to 13.5 ng/mL in vitro and from 42 to 1.6 ng/mL in the aqueous humor during 30 days. In the FCVB and silicone-treated groups, clinical inflammation almost was abolished; no bacteria were detected in the aqueous humor; TNF-α, IL-1β, and IFN-γ expression decreased; and relatively normal corneal and retinal architecture were kept after the 30-day treatment. The FCVB could provide us with dual functions, combining a levofloxacin drug delivery system and a vitreous substitute, to treat endophthalmitis in rabbit eyes.