Acanthamoeba keratitis
Acanthamoeba keratitis | |
eMedicine | med/10 |
---|---|
MeSH | D015823 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Acanthamoeba keratitis is a rare disease where amoebae invade the cornea of the eye.
Causes
In the United States, it is nearly always associated with contact lens use, as Acanthamoeba can survive in the space between the lens and the eye.[1][2][3][4] For this reason, contact lenses must be properly disinfected before wearing, and should be removed when swimming or surfing.
However, elsewhere in the world, many cases of Acanthamoeba present in non-contact lens wearers.[5][6]
Diagnosis
To detect Acanthamoeba on a contact lens in a laboratory, a sheep blood agar plate with a layer (a lawn) of E. coli is made. Part of the contact lens is placed on the agar plate. If Acanthamoeba are present, they will ingest the bacteria, leaving a clear patch on the plate around the area of the lens. Polymerase chain reaction can also be used to confirm a diagnosis of Acanthamoeba keratitis, especially when contact lenses are not involved. Acanthameoba is also characterized by a brawny edema and hazy view into the interior AC. Late stages of the disease also produces a ring shaped corneal ulcer.[7]
Presentation
Signs and symptoms include severe pain, severe keratitis (similar to stromal herpetic disease), corneal perineuritis, ring ulcer (although this is late in the disease process)
Treatment
One treatment used is PHMB.[8]
Propamidine isethionate has also shown some effectiveness.[9]
Another possible agent is chlorhexidine.[10]
Keratoplasty may sometimes be required.[9]
A combined regimen of propamidine, miconazole nitrate, and neomycin has also been suggested.[11]
References
- ↑ Auran, JD (1987). "Acanthamoeba keratitis. A review of the literature". Cornea. 6 (1): 2–26. doi:10.1097/00003226-198706010-00002. PMID 3556011. Unknown parameter
|coauthors=
ignored (help);|access-date=
requires|url=
(help) - ↑ JOHN D.T. (1993) Opportunistically pathogenic free-living amebae. In: J.P. Kreier and J.R. Baker (Eds.), Parasitic Protozoa. Vol. 3. Academic Press, New York, pp. 143–246.
- ↑ Badenoch, PR (1995). "Corneal virulence, cytopathic effect on human keratocytes and genetic characterization of Acanthamoeba". International journal for parasitology. 25 (2): 229–39. doi:10.1016/0020-7519(94)00075-Y. PMID 7622330. Unknown parameter
|month=
ignored (help); Unknown parameter|coauthors=
ignored (help);|access-date=
requires|url=
(help) - ↑ Niederkorn, JY (1999). "The pathogenesis of Acanthamoeba keratitis". Microbes and Infection. 1 (6): 437–43. doi:10.1016/S1286-4579(99)80047-1. PMID 10602676. Unknown parameter
|month=
ignored (help); Unknown parameter|coauthors=
ignored (help);|access-date=
requires|url=
(help) - ↑ Sharma S, Garg P, Rao GN. "Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis." The British Journal of Ophthalmology. 2000 Oct;84(10):1103-8. PMID: 11004092
- ↑ Bharathi JM, Srinivasan M, Ramakrishnan R, Meenakshi R, Padmavathy S, Lalitha PN (2007). "A study of the spectrum of Acanthamoeba keratitis: a three-year study at a tertiary eye care referral center in South India". Indian J Ophthalmol. 55 (1): 37–42. PMID 17189885.
- ↑ Pasricha, Gunisha (2003). "Use of 18S rRNA Gene-Based PCR Assay for Diagnosis of Acanthamoeba Keratitis in Non-Contact Lens Wearers in India". Journal of Clinical Microbiology. 41 (7): 3206–3211. doi:10.1128/JCM.41.7.3206-3211.2003. PMID 12843065. Unknown parameter
|coauthors=
ignored (help); Unknown parameter|month=
ignored (help) - ↑ Sharma S, Garg P, Rao GN (2000). "Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis". Br J Ophthalmol. 84 (10): 1103–8. PMC 1723254. PMID 11004092. Unknown parameter
|month=
ignored (help) - ↑ 9.0 9.1 Lindsay RG, Watters G, Johnson R, Ormonde SE, Snibson GR (2007). "Acanthamoeba keratitis and contact lens wear". Clin Exp Optom. 90 (5): 351–60. doi:10.1111/j.1444-0938.2007.00172.x. PMID 17697181. Unknown parameter
|month=
ignored (help) - ↑ Hammersmith KM (2006). "Diagnosis and management of Acanthamoeba keratitis". Curr Opin Ophthalmol. 17 (4): 327–31. doi:10.1097/01.icu.0000233949.56229.7d. PMID 16900022. Unknown parameter
|month=
ignored (help) - ↑ "Acanthamoeba: Treatment & Medication - eMedicine Infectious Diseases". Retrieved 2009-02-27.