In vivo and in vitro laser confocal microscopy to diagnose acanthamoeba keratitis.
OBJECTIVE
To determine the effectiveness of laser confocal microscopy in identifying Acanthamoeba cysts and trophozoites in the cornea of patients with Acanthamoeba keratitis (AK) and to evaluate its effectiveness in following AK after treatment.


METHODS
The corneas of 9 patients clinically diagnosed with AK were monitored periodically with the Heidelberg Retina Tomograph II-Rostock Cornea Module (HRT II-RCM) to examine for Acanthamoeba cysts and trophozoites during the clinical course.


RESULTS
Seven of 9 patients had positive corneal smears, and 5 of 9 patients had positive laboratory cultures. HRT II-RCM demonstrated the presence of highly reflective polygonal shadows with lower reflective borders in the cornea of all patients. In 1 patient, a highly reflective pleomorphic shadow with small less-reflective areas was detected inside the cell. The former finding resembled the image of Acanthamoeba cysts in culture as observed by HRT II-RCM, and the latter observation with that of Acanthamoeba trophozoites in culture. After treatment, the number of highly reflective inflammatory cells decreased and the number and morphology of the corneal epithelial cells with highly reflective nuclei recovered to normal levels.


CONCLUSIONS
These results indicate that in vivo laser confocal microscopy can be a useful method to make a diagnosis and to follow patients with AK.
Shiraishi
Atsushi
A
Department of Ophthalmology and Regenerative Medicine, Ehime University Graduate School of Medicine, Toon, Ehime, Japan. shiraia@m.ehime-u.ac.jp
Uno
Toshihiko
T
Oka
Naoko
N
Hara
Yuko
Y
Yamaguchi
Masahiko
M
Ohashi
Yuichi
Y
D000048:Acanthamoeba / Q000302:isolation & purification*; D015823:Acanthamoeba Keratitis / Q000175:diagnosis* / Q000188:drug therapy; D000293:Adolescent; D000328:Adult; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D002710:Chlorhexidine / Q000627:therapeutic use; D003315:Cornea / Q000469:parasitology*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D014054:Tomography; D055815:Young Adult
D000891:Anti-Infective Agents, Local; D002710:Chlorhexidine