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The Cochrane Database of Systematic... Feb 2015Acanthamoeba are microscopic, free-living, single-celled organisms which can infect the eye and lead to Acanthamoeba keratitis (AK). AK can result in loss of vision in... (Review)
Review
BACKGROUND
Acanthamoeba are microscopic, free-living, single-celled organisms which can infect the eye and lead to Acanthamoeba keratitis (AK). AK can result in loss of vision in the infected eye or loss of eye itself; however, there are no formal guidelines or standards of care for the treatment of AK.
OBJECTIVES
To evaluate the relative effectiveness and safety of medical therapy for the treatment of AK.
SEARCH METHODS
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015), PubMed (1948 to January 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 2015), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 9 January 2015.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) of medical therapy for AK, regardless of the participants' age, sex, or etiology of disease. We included studies that compared either anti-amoeba therapy (drugs used alone or in combination with other medical therapies) with no anti-amoeba therapy or one anti-amoeba therapy with another anti-amoeba therapy.
DATA COLLECTION AND ANALYSIS
Two authors independently screened search results and full-text reports, assessed risk of bias, and abstracted data. We used standard methodological procedures as set forth by the Cochrane Collaboration.
MAIN RESULTS
We included one RCT (56 eyes of 55 participants) in this review. The study compared two types of topical biguanides for the treatment of AK: chlorhexidine 0.02% and polyhexamethylene biguanide (PHMB) 0.02%. All participants were contact lens wearers with a median age of 31 years. Treatment duration ranged from 51 to 145 days. The study, conducted in the UK, was well-designed and had low risk of bias overall.Outcome data were available for 51 (91%) of 56 eyes. Follow-up times for outcome measurements in the study were not reported. Resolution of infection, defined as control of ocular inflammation, relief of pain and photosensitivity, and recovery of vision, was 86% in the chlorhexidine group compared with 78% in the PHMB group (relative risk (RR) 1.10, 95% confidence intervals (CI) 0.84 to 1.42). In the chlorhexidine group, 20 of 28 eyes (71%) had better visual acuity compared with 13 of 23 eyes (57%) in the PHMB group at final follow-up (RR 1.26, 95% CI 0.82 to 1.94). Five participants required therapeutic keratoplasty: 2 in the chlorhexidine group compared with 3 in the PHMB group (RR 0.55, 95% CI 0.10 to 3.00). No serious adverse event related to drug toxicity was observed in the study.
AUTHORS' CONCLUSIONS
There is insufficient evidence to evaluate the relative effectiveness and safety of medical therapy for the treatment of AK. Results from the one included study yielded no difference with respect to outcomes reported between chlorhexidine and PHMB. However, the sample size was inadequate to detect clinically meaningful differences between the two groups as indicated by the wide confidence intervals of effect estimates.
Topics: Acanthamoeba Keratitis; Anti-Infective Agents, Local; Biguanides; Chlorhexidine; Humans; Randomized Controlled Trials as Topic
PubMed: 25710134
DOI: 10.1002/14651858.CD010792.pub2 -
Journal of Postgraduate Medicine 1995Acanthamoeba keratitis, common in soft lens wearers, is not commonly isolated. The reports of Acanthamoeba keratitis in Indian literature are few. We report here a case...
Acanthamoeba keratitis, common in soft lens wearers, is not commonly isolated. The reports of Acanthamoeba keratitis in Indian literature are few. We report here a case of Acanthamoeba Keratitis in a medical student using soft contact lenses, initially diagnosed and treated as a bacterial and later as a viral corneal ulcer, who responded extremely well to medical line of therapy.
Topics: Acanthamoeba Keratitis; Adult; Antifungal Agents; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Ketoconazole; Treatment Outcome; Visual Acuity
PubMed: 10707721
DOI: No ID Found -
Translational Vision Science &... Feb 2024To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients.
PURPOSE
To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients.
METHODS
This retrospective study included 159 culture-confirmed AK patients. Patients' data were collected, including demographics, initial diagnosis, treatments, and clinical features. The genotype of Acanthamoeba was identified through sequencing the Diagnostic Fragment 3 (DF3) region in the small ribosomal subunit RNA genes. The phylogenetic tree was constructed using the ClustalW model and maximum likelihood method. Cases with "poor outcome" were defined based on specific clinical criteria, including corneal perforation, keratoplasty, other eye surgery, duration of anti-amoebic therapy ≥8.0 months, and final visual acuity ≤20/80. "Better outcome" cases were the remainder. The correlation between T4 subtypes, clinical phenotypes, and clinical prognosis were further analyzed.
RESULTS
In this study, AK was primarily attributed to the T4A genotype, with a positive correlation between geographical and genetic distances. The primary clinical associated with T4 subtypes was deep stromal infiltration. Results was also showed a significant association between T4 subtypes and clinical outcomes (P = 0.021). Further analysis revealed that T4C was closely associated with a better prognosis (P = 0.040) and T4D with worse outcomes (P = 0.013).
CONCLUSIONS
In China, AK was predominantly caused by the T4A subtype. Geographical distance positively correlated with genetic distance. Clinical prognosis varied among different subtypes, notably in T4C and T4D.
TRANSLATIONAL RELEVANCE
This study demonstrated the association between T4 subtypes and clinical phenotypes, as well as the effects of T4 subtypes on clinical prognosis.
Topics: Humans; Acanthamoeba Keratitis; Phylogeny; Retrospective Studies; Genotype; China
PubMed: 38329750
DOI: 10.1167/tvst.13.2.5 -
Optometry and Vision Science : Official... Mar 2021Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious...
SIGNIFICANCE
Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies.
PURPOSE
The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting.
METHODS
Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives.
RESULTS
The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed.
CONCLUSIONS
The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.
Topics: Academies and Institutes; Acanthamoeba Keratitis; Contact Lenses; Epidemiologic Studies; Eye Infections, Bacterial; Eye Infections, Fungal; Eye Infections, Parasitic; Humans; Incidence; Keratitis; Optometry; Risk Factors; United States
PubMed: 33771951
DOI: 10.1097/OPX.0000000000001664 -
Cornea Oct 2021To report the clinical and confocal findings of a unique case of combined Phialemonium curvatum and Acanthamoeba keratitis and to highlight the role of the prompt... (Review)
Review
PURPOSE
To report the clinical and confocal findings of a unique case of combined Phialemonium curvatum and Acanthamoeba keratitis and to highlight the role of the prompt diagnosis and specific medical treatment in preserving visual function.
METHODS
A case report and literature review.
RESULTS
A 54-year-old woman presented with a 3-day history of visual impairment, photophobia, and ocular pain in her right eye. Her best corrected visual acuity was 0.4 Logarithm of the Minimum Angle of Resolution scale, and the slit-lamp examination showed whitish corneal stromal infiltrate with satellite lesions. In vivo confocal microscopy evidenced Acanthamoeba cysts and fungal hyphae that resulted P. curvatum in the culture examination. The intensive medical treatment was started with topical 0.02% polyhexamethylene biguanide, voriconazole 1%, and moxifloxacin hydrochloride 0.5%. Progressive improvement of clinical and confocal pictures was registered with a complete recovery of visual function after 1 month.
CONCLUSIONS
This is the first case report of combined P. curvatum and Acanthamoeba keratitis. The fast diagnosis with in vivo confocal microscopy allowed early and intensive specific treatment with recovery of corneal infection.
Topics: Acanthamoeba Keratitis; Administration, Ophthalmic; Anti-Bacterial Agents; Antifungal Agents; Ascomycota; Biguanides; Disinfectants; Drug Therapy, Combination; Early Diagnosis; Eye Infections, Fungal; Female; Humans; Keratitis; Microscopy, Confocal; Middle Aged; Moxifloxacin; Mycoses; Ophthalmic Solutions; Slit Lamp Microscopy; Voriconazole
PubMed: 34481411
DOI: 10.1097/ICO.0000000000002660 -
BMJ (Clinical Research Ed.) Oct 1994
Topics: Acanthamoeba Keratitis; Contact Lenses, Hydrophilic; Humans; Water Supply
PubMed: 7848439
DOI: 10.1136/bmj.309.6960.1019b -
Journal of Clinical Pathology Apr 1993
Topics: Acanthamoeba Keratitis; Contact Lenses; Humans
PubMed: 8496403
DOI: 10.1136/jcp.46.4.382-b -
Journal of Clinical Pathology Apr 1992
Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Contact Lenses, Hydrophilic; Humans
PubMed: 1577982
DOI: 10.1136/jcp.45.4.367-b -
British Medical Journal (Clinical... Feb 1988
Topics: Acanthamoeba; Amebiasis; Animals; Contact Lenses; Humans; Keratitis
PubMed: 3126905
DOI: 10.1136/bmj.296.6621.568 -
The British Journal of Ophthalmology Apr 2003
Topics: Acanthamoeba Keratitis; England; Humans; Incidence; Risk Factors; Wales; Water Supply
PubMed: 12642336
DOI: 10.1136/bjo.87.4.516