Author/Authors :
Rezaei Kanavi, Mozhgan Ocular Tissue Engineering Research Center - Shahid Beheshti University of Medical Sciences, Tehran, Iran , Javadi, Fatemeh Shahed University of Medical Sciences, Tehran, Iran , Hosseini, Bagher Central Eye Bank of Iran, Tehran, Iran , Rakhshani, Nasser Central Eye Bank of Iran, Tehran, Iran , Javadi, Mohammad-Ali Central Eye Bank of Iran, Tehran, Iran
Abstract :
Purpose: To report impression cytology findings in specimens obtained from eyes with
clinical and confocal microscopic features of Acanthamoeba keratitis (AK).
Methods: In this interventional case series, impression cytology was obtained from
corneas of patients with clinical and confocal microscopic features indicative of AK.
Specimens were stained with Periodic acid-Schiff/Papanicolaou (PAS/PAP) and
examined for the presence of PAS-reactive Acanthamoeba cysts and/or hyperchromatic
pear-shaped trophozoites. All specimens were then decolorized and re-stained with
calcofluor white (CFW) for the presence of chemofluorescent cysts.
Results: Fifty-six eyes of 50 patients with mean age of 25.5±9.3 (range, 17 to 78) years
were evaluated. Forty-one (82%) cases were female and 51 (91.1%) eyes had history of
contact lens wear. PAS-reactive Acanthamoeba cysts and/or hyperchromatic pear-shaped
trophozoites were identified in 53 eyes (94.6%), 2 of which demonstrated only trophozoitelike
structures. CFW staining was able to reveal the presence of chemofluorescent cysts
in all 51 specimens (91.1%) in which cysts had been demonstrated with PAS/PAP
staining. Trophozoites were not detected with CFW due to background staining of the
cellulose acetate strip used for impression cytology.
Conclusion: Corneal impression cytology, stained with PAS/PAP or with CFW,
successfully detects Acanthamoeba and can be employed for early noninvasive diagnosis
of AK.
