[Correlation between histopathologic features and clinical outcomes of acanthamoeba keratitis].

Objective

To study the relationship between the clinical characteristics and the histopathological changes in acanthamoeba keratitis.

Methods

In this retrospective study, the clinical data and histopathological features of 15 Acanthamoeba keratitis patients (15 eyes) treated in Henan Eye Hospital were collected and analyzed. There were 8 males and 7 females. Mean age was 49.2 years old. The corneal specimens were stained with hematoxylin eosin, periodic acid-schiff, Gomori's methenamine silver, Gram and Gimsa respectively. The pathological changes and characteristics were observed under microscope, to analyze the relationship between histopathology and clinical features.

Results

All patients had moderate conjunctival congestion. Five patients showed corneal ring stromal infiltration, 8 had central corneal ulcers, 1 had corneal opacity, and 1 had a matrix ulcer. We found corneal neovascularization around the ulcer in 4 eyes and a dense ulcer in 2 eyes. Histopathological examinations with hematoxylin-eosin, periodic acid-Schiff, Gomori's methenamine silver, Gram and Giemsa stainings revealed round or oval amoebic cysts and amebic trophozoites which were of an elongated oval, spine-or spear-like. Twelve patients (80%) showed corneal stromal purulent inflammation infiltrated by neutrophils. Many degenerated amoebic cysts were found. Degeneration and necrosis of corneal stromal fibers were observed in 3 eyes (20%). There were no neutrophils. Amoebic cysts were seen in necrotic tissue. Ten eyes (66.7%) had no inflammatory cell infiltration areas, with edematous or mildly degenerated corneal fibers, scattered or grouped cysts and trophozoites.

Conclusions

Clinical manifestations of acanthamoeba keratitis are various. Acanthamoeba cysts and trophozoites also exist in the transparent corneal area on the histopathological examination. This is important for the therapeutic outcomes. (Chin J Ophthalmol, 2021, 57: 939-943).