Contact lens wearers at greater risk for Acanthamoeba keratitis than non-lens wearers
LAS VEGAS — In patients who are diagnosed with Acanthamoeba keratitis, 85% to 100% are contact lens wearers and 33% are orthokeratology patients, according to a speaker here.
“The rates of risk are the same or very similar for hard and soft contact lens wearers. Orthokeratology patients are especially high risk... luckily, if you are a noncontact lens wearer, the risk is fairly low,” Elmer Y. Tu, MD, said at Cornea Subspecialty Day preceding the American Academy of Ophthalmology annual meeting.
Any contact lens-related keratitis that does not resolve with standard antibacterial therapy should be considered a possible case of Acanthamoeba keratitis, he said, adding that a majority of patients are treated for other diagnoses before the diagnosis of Acanthamoeba keratitis is made, he said.
“It is absolutely critical that the clinician understands the risk factors associated with Acanthamoeba keratitis because it could look about just like anything else,” Tu said.
A study conducted by Tu and colleagues in 2007 found that the main prognostic factor that determines outcome is level of disease.
“You have a 10 times greater risk of not ... seeing well if you did not recognize this disease in the early stages,” Tu said.
Currently, there are no treatments that have been approved by the FDA for Acanthamoeba keratitis.
“Treatment with biguanides is generally successful but may take an extended period of time,” Tu said.
Surgical intervention could be considered in refractory cases, although indications for surgical intervention for Acanthamoeba keratitis remain controversial, he said.
“Recognize the disease in a timely manner and make every effort to give a specific diagnosis, and at that point institute prompt and aggressive therapy,” he said. — by Nhu Te
Tu E. Management of amoebic infections. Presented at: The American Academy of Ophthalmology. Nov. 14; Las Vegas.
Disclosure: Tu reports no relevant financial disclosures.