Imaging Fungal Hyphae and Infection-Induced Stromal Changes in Ex Vivo Porcine Corneas Using Line-Field Spectral Domain Optical Coherence Microscopy

Microbial keratitis requires rapid diagnosis to enable timely, pathogen-directed treatment. Corneal confocal microscopy (CCM) is used to quickly diagnose acanthamoeba and fungal keratitis, but it relies on undesirable contact objective lenses, and no supplier has maintained a stable market presence. Here, we present a preliminary investigation of the potential abilities of non-contact optical coherence microscopy (OCM) as an emerging alternative technology. Using an ex vivo porcine corneal infection model, we demonstrate that OCM can produce en face images, similar to CCM, as well as 3D visualizations of fungi hyphae in stromal tissue. Like CCM, bacterial pathogens were too small to directly identify in OCM images. Nevertheless, OCM detected that ex vivo infection induced systematic changes to the stroma that are consistent with the breakdown of keratocyte structure. These proof-of-concept results demonstrate the potential of non-contact OCM for imaging microbial keratitis and support further in vivo evaluation.