Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013:2013:670242.
doi: 10.1155/2013/670242. Epub 2013 Jun 12.

Acanthamoeba keratitis: a 12-year experience covering a wide spectrum of presentations, diagnoses, and outcomes

Michael A Page  1 , William D Mathers
Affiliations

Acanthamoeba keratitis: a 12-year experience covering a wide spectrum of presentations, diagnoses, and outcomes

Michael A Page et al. J Ophthalmol. 2013.

Abstract

Purpose. To review characteristics of confocal microscopy, clinical presentation, and clinical outcome in 372 cases of Acanthamoeba keratitis (AK) from 1999 to 2011. Methods. A retrospective case review was performed on 372 cases of AK diagnosed by confocal microscopy (CFM) at a single institution in Portland, Oregon, from 1999 to 2011. A numbered grading system was devised for describing the relative microscopic severity of the AK infections detected. Results. "grade 1," 94 as "grade 2," 40 as "grade 3," and 62 as "grade 4." Peak incidences occurred during 2000-2002 and 2005-2007. Seasonal variation was noted, with a peak during summer months. For the 231 cases with complete records, 64% indicated a history of soft contact lens use. Nine progressed to multiple failed penetrating keratoplasties (PKPs) or enucleation. Conclusion. We report an average of 31 new cases of AK per year from 1999 to 2011. This figure equates to 10.3 new cases/1,000,000/year for the Portland metropolitan area. Patients diagnosed with AK exhibited a wide spectrum of clinical and microscopic characteristics. Soft contact lens use remained the single largest risk factor.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Severity grade 1 ((a) and (b)): few cysts, confined to epithelium (note variable size of Acanthamoeba organisms in (a) and Langerhans cells in (b)), confined to small area of the cornea. Severity grade 2 ((c) and (d)): more numerous cysts with clearer morphology, limited to epithelium, confined to small area of the cornea.
Figure 2
Figure 2
Severity grade 3 ((a) and (b)): numerous cysts, definite morphology, may or may not involve deeper corneal tissues, more densely concentrated. Severity grade 4 ((c) and (d)): numerous cysts and trophozoites, definite morphology, deeper corneal layers involved, densely concentrated, wide corneal area involvement.
Figure 3
Figure 3
Number of AK cases diagnosed by CFM from 1999 to 2010, annual and monthly average, denoted by grade.
See this image and copyright information in PMC

References

    1. Naginton J, Watson PG, Playfair TJ, McGill J, Jones BR, Steele AD. Amoebic infection of the eye. The Lancet. 1974;2(7896):1537–1540. - PubMed
    1. Niederkorn JY, Alizadeh H, Leher H, McCulley JP. The pathogenesis of Acanthamoeba keratitis. Microbes and Infection. 1999;1(6):437–443. - PubMed
    1. Bacon AS, Dart JKG, Ficker LA, Matheson MM, Wright P. Acanthamoeba keratitis: the value of early diagnosis. Ophthalmology. 1993;100(8):1238–1243. - PubMed
    1. Parmar DN, Awwad ST, Petroll WM, Bowman RW, McCulley JP, Cavanagh HD. Tandem scanning confocal corneal microscopy in the diagnosis of suspected Acanthamoeba Keratitis. Ophthalmology. 2006;113(4):538–547. - PubMed
    1. Stehr-Green JK, Bailey TM, Visvesvara GS. The epidemiology of Acanthamoeba keratitis in the United States. The American Journal of Ophthalmology. 1989;107(4):331–336. - PubMed

LinkOut - more resources