Guidelines For Management Of Acanthamoebic Keratitis

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR221 | Type: Free paper | DOI: 10.82333/72x2-mk48

Authors: Dr Ahmed Khattab* ¹

¹Alexandria Ophthalmology General Hospital ,Alexandria,Egypt

Purpose

DIAGNOSIS

•Clinical suspicion of acanthamoebickeratitis especially contact lenses wearers, or anyone who is demonstrating severe ocular pain.

Setting

Corneal scraping for microbial culture has a high specificity (100%) but low sensitivity (7–66.7%) depending upon culture techniques. Amoebic culture takes, on average, up to 10 days to demonstrate a positive result.

PCR has a high specificity (100%) with moderately better sensitivity (66.7–100%). It is a rapid method but somehow expensive.

In vivo confocal microscopy is a growing, non-invasive diagnostic tool with very high specificity (100%) and a high sensitivity, ranging from 85.3–100%.

Methods

MEDICAL THERAPY

•Isusually administered through the form of topical eye drops

•Given every hour initially for the first few days. The minimum time for treatment is 3–4 weeks

TOPICAL ANTIPROTOZOAL AGENTS

1- Biguanides can kill both forms of Acanthamoeba, trophozoites and cysts.

•The two biguanide compounds consistently proven effective in a drug treatment are polyhexamethlyenebiguanide (PHMB) (Baquacil 0.02% & 0.04%) and chlorhexidine 0.02%.

•They seem to have less toxicity problems when compared to other antiprotozoal drugs.

•Their side effects involve an elevated intraocular pressure and toxic keratopathy.

2- Aromatic Diamidines such as propamidine isetionate(Brolene) and hexamidine (Desmodine) are usually used in combination with biguanides.

Results

ANTIBIOTICS

•Neomycin can eliminate the trophozoite form of Acanthamoeba but does not have a high cysticidal activity. Using neomycin in a “triple therapy” such as with propamidine and dibromopropamidine has effectively treated many AK patients.

STEROIDS

•The use of corticosteroids to decrease the intense inflammation that occurs in AK is controversial because of the disadvantage of potentially promoting encystmentand increasing trophozoites.

•Although there is no evidence against using corticosteroids after beginning treatment, there is data that individuals with a history of corticosteroid use before diagnosis are more likely to fail initial treatment of AK.

Conclusions

SURGICAL THERAPY

•Indicated if the recommended treatment of biguanides and aromatic diamidines fails and the infection has progressed to an advanced stage.

•Keratoplasty is most useful for patients who are experiencing vision loss due to either the advanced stromal destruction induced by uncontrolled infection or corneal scarring after medical eradication of the infection.