Diagnosis and successful medical treatment of Acanthamoeba keratitis
G. D'Aversa, G. A. Stern and W. T. Driebe Jr
Department of Ophthalmology, University of Florida College of Medicine, Gainesville, USA.
OBJECTIVE: To identify the methods that result in timely diagnosis and
effective treatment of Acanthamoeba keratitis. METHODS: We retrospectively
reviewed the medical records of 12 consecutive patients whom we treated for
culture-proved Acanthamoeba keratitis in 14 eyes. RESULTS: Contact lenses
were worn in 13 of 14 affected eyes and substandard methods were often used
to care for them. The diagnosis was established in all patients by
laboratory analysis of corneal scrapings; corneal biopsies were not
required. Acanthamoeba organisms were identified on smears from 12 of 14
eyes with use of standard, nonfluorescent stains and recovered in culture
from all patients by inoculating scrapings on nonnutrient agar overlaid
with Escherichia coli. Eleven of 14 eyes were medically cured with a
combination of antiamebic drugs, most commonly propamidine isethionate,
neomycin sulfate, and clotrimazole. Topical corticosteroids were used in
only one patient. Two of the three eyes that required therapeutic
keratoplasty were not treated before surgery according to our usual
protocol; the third required keratoplasty for treatment of a severe
bacterial superinfection. Twelve of 14 eyes recovered 20/50 or better
visual acuity. Bacterial superinfections were a serious problem, with a
total of six superinfections occurring in three treated eyes. CONCLUSION:
With timely diagnosis and medical treatment with a combination of
antiamebic drugs and avoidance of topical corticosteroids, most cases of
Acanthamoeba keratitis can be cured, with an excellent prognosis for visual
recovery.
