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PubMed · 7712613

Acanthamoeba keratitis.

J P McCulley·H Alizadeh·J Y Niederkorn
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Abstract

The incidence of Acanthamoeba keratitis has decreased significantly, and it is no longer a reportable condition in the United States. Corneal abrasion and contact lenses play an important role in the development of Acanthamoeba keratitis. One of the most important features of the disease is severe pain, which is atypical for herpes simplex. The pathognomonic sign for Acanthamoeba is radial neuritis or inflammation around the corneal nerve caused by the parasites. The most important step in prevention of Acanthamoeba keratitis is effective education of patients about the care of contact lenses. A combination of Brolene and Neomycin is the best approach in treating Acanthamoeba keratitis. However, if treatment with these drugs fails, clotrimazole is recommended.

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Acanthamoeba KeratitisAnimalsContact LensesHumansJournal ArticleResearch Support, Non-U.S. Gov'tReview

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J P McCulley, H Alizadeh, J Y Niederkorn. 1995. Acanthamoeba keratitis.. https://pubmed.ncbi.nlm.nih.gov/7712613/

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Acanthamoeba sclerokeratitis: treatment with systemic immunosuppression.

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PubMed2002

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A 37-year-old women developed severe suppurative keratitis immediately after having photorefractive keratectomy in her left eye. The keratitis was unresponsive to intensive topical antibiotic agents and topical and systemic steroids. Although the differential diagnosis included nonmicrobial and fungal keratitis, the clinical course and confocal microscopy suggested, and subsequent histopathologic examination confirmed, a diagnosis of Acanthamoeba keratitis. The amebic contamination probably resulted from exposure of the deepithelialized cornea to contaminated freshwater in a northern Wisconsin marsh. This case emphasizes the importance of encouraging patients with epithelial defects and bandage soft contact lenses to avoid exposure to contaminated freshwater until reepithelialization is complete.

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PURPOSE: To establish the incidence, etiology and risk factors for microbial keratitis (MK) in Hong Kong. METHODS: Two hundred and twenty-three new cases of presumed MK were recruited over a period of 17 months and comprehensive microbiologic studies performed. A nested case-control study was pursued for patients wearing contact lenses (CLW) to determine risk factors for MK with regards to types of CLW and hygiene practice. RESULTS: Of the 223 patients recruited, 59 (26%) wore contact lenses. Corneal scrapes yielded positive cultures from 77 patients (35% overall, 56 non-CLW, 21 CLW). Two hundred and six CLW volunteers were recruited to participate in the case-control study, of whom 135 were matched with 45 CLW patients. The annual incidence of MK was 0.63 per 10,000 population and 3.4 per 10,000 CLW with rates for daily, extended and rigid lens wear of 3.09, 9.30 and 0.44 per 10,000 CLW respectively. Pseudomonas aeruginosa was the dominant bacterial pathogen. Six cases of Acanthamoeba keratitis occurred, five in CLW (incidence 0.33 per 10,000 CLW) and one following corneal abrasion. Non-CLW developed MK at a peak age of 73, which is 10 years younger than expected for Scotland and USA. CONCLUSIONS: Previous ocular surface disease and trauma were the main risk factors for MK in Hong Kong. CLW appears at least as safe as that found in Scotland and the USA. Acanthamoeba keratitis was detected but with an incidence rate five times lower than Scotland. Factors predisposing hydrogel CLWs to MK, that were statistically significant, included overnight wear, poor hygiene and smoking.

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