Treatment of Acanthamoeba Keratitist

Lindquist, Thomas D.

doi:10.1097/00003226-199801000-00002

Cited by 64 publications

(37 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although not licensed for therapeutic use, it has been employed as a successful experimental treatment for AK by Larkin et al (250). A combination of chlorhexidine digluconate (a bisbiguanide) with PHMB (a polymeric biguanide) or with aromatic diamidines such as hexamidine, pentamidine, and propamidine isethionate or PHMB and hexamidine with debridement has been reported for the treatment of AK (124,161,171,175,195,196,250,260,323,365,405,447,454,482). PHMB alone does not appear to be associated with toxicity, but other compounds used in combination with PHMB may exert untoward effects (195).…”

Section: Amebic Keratitismentioning

confidence: 99%

Acanthamoebaspp. as Agents of Disease in Humans

2003

View full text Add to dashboard Cite

Acanthamoeba spp. are free-living amebae that inhabit a variety of air, soil, and water environments. However, these amebae can also act as opportunistic as well as nonopportunistic pathogens. They are the causative agents of granulomatous amebic encephalitis and amebic keratitis and have been associated with cutaneous lesions and sinusitis. Immuno compromised individuals, including AIDS patients, are particularly susceptible to infections with Acanthamoeba. The immune defense mechanisms that operate against Acanthamoeba have not been well characterized, but it has been proposed that both innate and acquired immunity play a role. The ameba's life cycle includes an active feeding trophozoite stage and a dormant cyst stage. Trophozoites feed on bacteria, yeast, and algae. However, both trophozoites and cysts can retain viable bacteria and may serve as reservoirs for bacteria with human pathogenic potential. Diagnosis of infection includes direct microscopy of wet mounts of cerebrospinal fluid or stained smears of cerebrospinal fluid sediment, light or electron microscopy of tissues, in vitro cultivation of Acanthamoeba, and histological assessment of frozen or paraffin-embedded sections of brain or cutaneous lesion biopsy material. Immunocytochemistry, chemifluorescent dye staining, PCR, and analysis of DNA sequence variation also have been employed for laboratory diagnosis. Treatment of Acanthamoeba infections has met with mixed results. However, chlorhexidine gluconate, alone or in combination with propamidene isethionate, is effective in some patients. Furthermore, effective treatment is complicated since patients may present with underlying disease and Acanthamoeba infection may not be recognized. Since an increase in the number of cases of Acanthamoeba infections has occurred worldwide, these protozoa have become increasingly important as agents of human disease

show abstract

Section: Amebic Keratitismentioning

confidence: 99%

Acanthamoebaspp. as Agents of Disease in Humans

2003

View full text Add to dashboard Cite

show abstract

“…10,11 The treatment of Acanthamoeba keratitis is most successful in those cases in which the diagnosis is made very early. 11,[12][13][14] However, the most important aspect in the management of Acanthamoeba keratitis is prevention. Therefore the use of contact lens storage solutions that reliably kill Acanthamoeba trophozoites and cysts is of great importance.…”

Section: Introductionmentioning

confidence: 99%

One- and two-step hydrogen peroxide contact lens disinfection solutions against Acanthamoeba: How effective are they?

Hiti

Walochnik

Faschinger

et al. 2004

Eye

View full text Add to dashboard Cite

Purpose Effective contact lens disinfection solutions are important to keep the storage case free of acanthamoebae and thus prevent an infection of the eye. The aim of our study was to evaluate the effectivity of two new onestep hydrogen peroxide disinfecting solutions against Acanthamoeba spp. and compare it to the effectivity of other commercially available systems. Methods Nine one-step 3% hydrogen peroxide systems including the new systems Silver Sept (platinum and silver disk for intensifying disinfection) and Blue Vision (newly composed catalytic tablet) and 2 two-step systems (0.6 and 3.0% H 2 O 2 ) were tested for their effectivity against cysts of two Acanthamoeba keratitis isolates at different concentrations.Results After a soaking time of 8 h (overnight soaking of contact lenses) the 2 two-step systems completely destroyed the cysts of both Acanthamoeba strains, even at the highest concentration of cysts tested. The nine tested one-step systems showed weaker effects. The new Blue Vision system was able to eradicate the cysts of one strain at the low concentration of cysts. Conclusions One-step hydrogen peroxide systems do not have sufficient effects on Acanthamoeba cysts and therefore may not protect the contact lens user from a possible infection of the eye. Further development of tablets like the ones used in the Blue Vision system may result in better cysticidal effects for one-step systems.

show abstract

“…Topical therapy with cysticidal agents remains the mainstay of therapy (18,19). Polyhexamethylene biguanide has been demonstrated to be effective, especially if applied in conjunction with other agents.…”

Section: Case Presentationmentioning

confidence: 99%

Acanthamoeba Species Keratitis in a Soft Contact Lens Wearer Molecularly Linked to Well Water

Mubareka

Alfa

Harding

et al. 2006

Canadian Journal of Infectious Diseases and Medical Microbiolog

View full text Add to dashboard Cite

An otherwise-healthy 14-year-old female soft contact lens wearer, who lived in a rural area where the tap water source for the home was a well, presented to a community hospital with a four-week history of progressive redness, swelling and blurred vision of her left eye despite treatment with topical neomycin and corticosteroids. A dendritiform corneal epithelial lesion, corneal edema and inflammation in the anterior chamber were noted on initial examination, and treatment for herpes simplex keratouveitis with oral valacyclovir and topical trifluridine 1% was initiated. There was no clinical improvement, and six weeks after the onset of symptoms she was referred to a corneal specialist for evaluation and further management. The patient's visual acuity was 20/80 and her corneal sensation was intact; slit-lamp examination revealed diffuse corneal edema, areas of punctate epithelial staining, poorly defined subepithelial and anterior stromal infiltrates, a partial ring infiltrate and 2+ cell and flare in the anterior chamber (Figure 1). The patient underwent corneal debridement, and scrapings were sent for viral, bacterial and Acanthameoba culture. She was admitted to the hospital, and polyhexamethalene biguanide 0.02% and diamidine propamidine isothianate eye drops were added to antiviral therapy and topical neomycin. Over the next few days, her visual acuity decreased to hand movement only, the corneal edema intensified, and midstromal peripheral vascularization developed. Her corneal epithelium healed promptly following debridement. Treatment with oral itraconazole, topical chlorhexidine 0.02% and topical ciprofloxacin were added after Acanthameoba species were isolated from corneal scrapings. Over the next few months, the patient improved markedly (her left visual acuity was 20/50) despite significant corneal vascularization and persisting central stromal opacity.Clinical samples, including corneal scrapings, contact lenses, contact lens solution, tap water and well water, were inoculated directly onto non-nutrient agar with Escherichia coli overlay (1), as well as sheep's blood agar, MacConkey agar and chocolate agar. The non-nutrient agar with E coli overlay was incubated at room temperature. The agar surface of the plates was examined daily with an inverted microscope at 10× magnification. On day 5 after planting, the plates inoculated by corneal scrapings were positive for both the cyst (Figure 2) and trophozoite forms of Acanthamoeba species. In addition, Serratia marcescens and Stenotrophomonas maltophilia were isolated from corneal scrapings that were inoculated onto sheep's blood agar, MacConkey agar and chocolate agar. Environmental samples consisting of well water and tap water from the patient's home, in addition to samples from the contact lens case, were also positive for Acanthamoeba species. Acanthamoeba species isolates were forwarded to the Ohio State University Department of Molecular Genetics (Columbus, Ohio, USA), where molecular epidemiological analysis was undertaken. This consisted of amp...

show abstract

Treatment of Acanthamoeba Keratitist

Cited by 64 publications

References 0 publications

Acanthamoebaspp. as Agents of Disease in Humans

Acanthamoebaspp. as Agents of Disease in Humans

One- and two-step hydrogen peroxide contact lens disinfection solutions against Acanthamoeba: How effective are they?

Acanthamoeba Species Keratitis in a Soft Contact Lens Wearer Molecularly Linked to Well Water

Contact Info

Product

Resources

About