Advantages and pitfalls of confocal microscopy for detection of AK

Abstract

AbstractCorneal infection by the diverse genotypes of the acanthamoeba parasite is becoming an increasingly common aetiology of serious cases of microbial keratitis in Europe, due in part to the growing use of contact lenses. The detection and diagnosis of acanthamoeba keratitis (AK), however, remains challenging in a clinical setting. Several diagnostic methods are typically used, including culture, clinical signs and symptoms, RTPCR, and in vivo confocal microscopy (IVCM). Only IVCM, however, is able to give a rapid and objective result that is not dependent on the location of a limited biopsy sample. Nevertheless, IVCM has both advantages and limitations for AK assessment when applied in a real‐world setting. An overview is given of the current knowledge on distinguishing features of AK when assessed by IVCM, and several challenging cases of suspected AK will be presented, along with considerations regarding how to assess characteristic features seen in IVCM images, that can either be indicative of AK infection, or conversely be features masquerading as AK‐specific findings. Finally, recommendations for the use of IVCM in the clinic for AK assessment, diagnosis and follow‐up will be given.