Overview
Acanthamoeba keratitis is an infectious corneal ulcer caused by the free-living amoeba Acanthamoeba, often associated with contact lens wear, trauma, and exposure to contaminated water sources 5.Diagnosis
Clinical Presentation: Redness, photophobia, tearing, blurred vision 2.
Diagnostic Tests:
- Corneal scraping cultures 25.
- Confocal microscopy 24.
- Giemsa stain and cultures of corneal scrapings 6.
Pathogen Identification: Postoperative pathological examinations confirm diagnosis 2.Management
First-Line Treatments:
- Polyhexamethylene biguanide (PHMB) 14.
- Combination therapy with multiple agents (e.g., biguanides and diamidines) 4.
Adjunctive Treatments:
- Topical corticosteroids used by some practitioners, though evidence varies 4.
- Penetrating keratoplasty for severe cases 24.Special Populations
Contact Lens Wearers: High risk, especially with soft lenses and exposure to contaminated water 5.
No Specific Guidance: Limited data on pregnancy, pediatrics, and elderly populations from provided abstracts.Key Recommendations
Utilize a combination of clinical examination and culture for diagnosis of Acanthamoeba keratitis (Evidence: Moderate 25).
Employ polyhexamethylene biguanide as a first-line monotherapy or as part of combination therapy (Evidence: Expert opinion 4).
Consider confocal microscopy as an adjunctive diagnostic tool to improve early detection (Evidence: Moderate 4).
Evaluate the need for penetrating keratoplasty in cases with poor response to medical therapy (Evidence: Expert opinion 24).
Enhance hygiene and disinfection protocols in ophthalmology wards to reduce environmental contamination risks (Evidence: Weak 3).References
1 Karpinecz B, Edwards N, Zderic V. Ultrasound-Enhanced Drug Delivery for Treatment of Acanthamoeba Keratitis. Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2019. link
2 Zhong J, Li X, Deng Y, Chen L, Zhou S, Huang W et al.. Associated factors, diagnosis and management of Acanthamoeba keratitis in a referral Center in Southern China. BMC ophthalmology 2017. link
3 Lasjerdi Z, Niyyati M, Lorenzo-Morales J, Haghighi A, Taghipour N. Ophthalmology hospital wards contamination to pathogenic free living Amoebae in Iran. Acta parasitologica 2015. link
4 Oldenburg CE, Acharya NR, Tu EY, Zegans ME, Mannis MJ, Gaynor BD et al.. Practice patterns and opinions in the treatment of acanthamoeba keratitis. Cornea 2011. link
5 Tanhehco T, Colby K. The clinical experience of Acanthamoeba keratitis at a tertiary care eye hospital. Cornea 2010. link
6 Girija T, Kumari R, Kamath MG, Ramani R, Mohan R, Shivananda PG. Acanthamoeba keratitis--a report of two cases. Indian journal of ophthalmology 1992. link