Abstract
Purpose:
To investigate in vivo corneal changes of keratoneuritis in early stage Acanthamoeba keratitis (AK) using in vivo laser confocal microscopy.
Methods:
Thirteen eyes (twelve patients, five men, seven women; mean age, 22.3 ± 4.2 years) with keratoneuritis due to early stage AK participated in this study.
Results:
In all patients, Acanthamoeba cysts were clearly observed in the basal epithelial cell layer as highly reflective round-shaped particles with a diameter of 10 to 20 μm. Bowman’s layer infiltration of Acanthamoeba cysts was observed in only one case, and no cases showed stromal and/or nerve infiltration of Acanthamoeba cysts. In the stroma, all cases showed highly reflective activated keratocytes forming a honeycomb pattern; these changes were significant around the keratoneuritis. Infiltration of inflammatory cells, possibly polymorphonuclear cells, was observed along with keratocyte bodies in all cases. Numerous highly reflective spindle-shaped materials were observed around the keratoneuritis. Most notably, highly reflective patchy lesions were observed around the keratoneuritis in eleven cases (84.6%). Inflammatory cells were also observed in the endothelial cell layer in four cases (30.8%).
Conclusions:
In vivo laser confocal microscopy identified consistent corneal abnormalities around keratoneuritis in early stage AK patients, of which highly reflective patchy lesions may be characteristic to keratoneuritis. Further morphological studies of corneas with early stage AK in a larger number of patients may elucidate the clinical significance of radial keratoneritis and may help us to understand the interaction between Acanthamoeba organisms and host corneal cells or nerves.
Keywords: 418 amoeba •
596 microscopy: confocal/tunneling