This study aims to compare the effects of voriconazole (VCZ) and liposomal amphotericin B (AmpB) in an experimental model of exogenous Aspergillus fumigatus endophthalmitis in a guinea pig animal model. Endophthalmitis was induced by intravitreal injection of a strain of aspergillus isolated from a patient with fungal endophthalmitis. Thirty animals of similar weight were divided into three groups; a control group receiving balanced salt solution intravitreal injections, a VCZ group receiving 20μg/0.02mL intravitreal injections of VCZ and an AmpB group receiving 20μg/0.02mL of AmpB. These were administered 24 hours after Aspergillus inoculation and repeated every 24 hours for a total of three injections. They also calculated a minimum inhibitory concentration value for both antifungals, which were consistent with the results, reported by Clinical and Laboratory Standards Institute and doses administered intravitreally were much higher than these. Clinical inflammation using a published grading scale was used until day 28. Furthermore, smears and cultures were performed weekly, as well as serial electroretinogram recordings and histopathology of whole eye at the end of 28 days. Reassuringly both antifungal treatments demonstrated antifungal effects when compared to the control. Control eyes showed marked progressive inflammation but antifungal treatment groups showed inflammation, which gradually subsided. ERG in control groups demonstrated obvious reduction in b wave amplitude where else both antifungal groups did not. There was a significant difference in clinical inflammation and ERG recordings from day seven to 14 showing AmpB was less effective than VCZ, but this was not observed at later stage outcomes, therefore it is hard to conclude that VCZ is superior although the authors claims this. This study is enlightening as it allows for a controlled in vivo experiment for exogenous fungal endophthalmitis which would normally not be possible in patients due to variable inoculation times of infection, presentations and not to mention ethics.

A comparative treatment study of intravitreal voriconazole and liposomal amphotericin B in an Aspergillus fumigatus endophthalmitis model.
Zhao J, Cheng Y, Song X, 
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Wai Siene Ng

University Hospital of Wales, Cardiff, UK.

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