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Diagnosis Case Study
Acanthamoeba infections are commonly misdi- A unique case involved a woman in her 40s. This
agnosed as other ocular disorders. They are often patient wore gas-permeable hard contact lenses for
mistaken as herpes simplex infection or an adenovirus extended periods of time, longer than she was di-
infection. It can also be thought to be a bacterial or rected to wear them. She developed a small corneal
fungal infection. It is often only correctly diagnosed abrasion as a result of her increased contact lens wear.
after viral, bacterial, or fungal treatments have failed During this time, she was on a weekend trip and used
to stop the progression of the infection. Unfortunate- the water from the hotel faucet to wash her face. It is
ly, this delay allows Acanthamoeba ample time to believed that this is when the Acanthamoeba infec-
progress deeper into the cornea, thus causing perma- tion began. The patient began experiencing pain in
nent tissue damage and more severe symptoms in the the eye. She returned home and was examined by
patient. Proper diagnosis first involves an accurate her general ophthalmologist the next day. She was
slit-lamp evaluation. A direct in vivo diagnosis can be evaluated and given a prescription for antibiotics to
performed using an advanced tandem scanning con- clear up her infection and speed the healing of the
focal microscope and a Heidelberg retina tomograph corneal abrasion. Three days later, her pain became
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II with cornea module. Histological examination can worse and she returned to her ophthalmologist for
be done as well; however, this requires material ob- follow-up. He noted no improvement in her condition
tained from a corneal biopsy or keratoplasty. If these and recommended that she consult a corneal special-
methods are not available, culturing results of a cor- ist. Two days later she saw a corneal specialist, who
neal scraping can be used to diagnose Acanthamoeba performed a corneal scraping procedure. The scraping
infection. was then cultured and after 3 weeks it was diagnosed
as Acanthamoeba infection. The patient was admit-
Treatment ted to a hospital for aggressive treatment. She was in
Treating Acanthamoeba infection can be a challenge. the hospital for 3 weeks for around-the-clock treat-
Early diagnosis followed by aggressive treatment is ment. She continued treatment from her home for
essential for a successful prognosis. Early detection the next 10 months because the infection seemed to
followed by aggressive treatment is imperative for a be resolving and her prognosis was good for a future
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successful outcome. Topical anti-infectives can be corneal transplant procedure. Unfortunately, her pain
used to treat the early stages of the infection. The best became severe again, which required high doses of
results have been observed using a combination of an- strong pain relievers. It was then determined that the
ti-amoebic cationic antiseptic drugs. These drugs in- Acanthamoeba infection had progressed beyond the
clude polyhexamethylene biguanide or chlorhexidine cornea, and there was the threat of it reaching the op-
digluconate paired with propamidine isethionate or tic nerve, a pathway to her brain. She was referred to
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hexamidine. If a bacterial infection is also suspected, an oculoplastic surgeon for enucleation. She was later
antibiotics such as neomycin or chloramphenicol can fit with a custom ocular prosthesis and has done very
be administered. Corticosteroids are also sometimes well wearing her prosthesis. She has not experienced
prescribed to decrease inflammation and pain, but any other Acanthamoeba infections to date.
they can simultaneously increase the pathogenicity
of the amoebae by suppressing the patient’s immune
response. Corticosteroids can be administered to help
minimize inflammation and pain, but they can have
an adverse effect in decreasing the patient’s immune
response in fighting the amoebae. In advanced cases
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of A. keratitis, surgical treatment may be required.
Penetrating keratoplasty is used to remove and replace
the infected/damaged tissue. A strict regime of anti-
septic drugs is recommended topically for up to 1 year
after surgery to prevent a recurrence of the infection.

JOURNAL OF OPHTHALMIC PROSTHETICS ACANTHAMOEBA KERATITIS: THE OCULAR NIGHTMARE | 41