Use Fusarium Cases to Emphasize Proper Lens Care
BY LEO SEMES, OD, FAAO
the realm of microbial keratitis (MK), fungal infections are a rare occurrence.
Among corneal fungal infections, Fusarium species occupy a
minor position. The recent publicity of a cluster of cases, however, has made us all aware of this entity.
Recognize the Condition
First, you should heed the blitz of information that has bombarded us recently regarding recognition, risk, appearance, treatment options and outcomes for fungal keratitis with lens wear. The ulcer is generally circular with feathery edges and may have an immune ring. The eye may appear quieter than in bacterial MK.
Advise your patients to wear and care for their contact lenses as directed and to treat and replace the contact lens case monthly. This is critical because Fusarium can reside almost anywhere, including tap water. For this reason, advise patients to use only sterile solutions for anything that touches the contact lens, the case and the eye.
Information for patients from the American Optometric Association (AOA) about fungal keratitis and how to prevent it, including a reference image of the condition, is available at www.aoa.org/x5119.xml. A comprehensive clinical guidance specifically for clinicians is available at www.aoa.org/x5166.xml.
With apprehension and anxiety running high, reassure patients that they will be safe when they care for their lenses properly. Emphasize that they wear and replace their lenses based on the appropriate schedule. Instruct them to remove and disinfect daily wear lenses overnight. Mention that the most effective defense against microbial organisms of any sort is to rinse, rub and re-rinse the lens before disinfection. This scheme provides the highest level of protection from infection.
Patients at greatest risk for fungal keratitis are those who live in warmer and more humid environments, those who don't follow instructions regarding lens wear and care and those who are in situations where vegetative matter may be a potential contaminant.
When faced with a Fusarium infection, topical treatment should include intensive Natacyn (natamycin 5% suspension, Alcon Laboratories) for the first three days with continued treatment over the next seven to 14 days. An alternative is amphotericin B (Fungizone, Bristol Myers Squibb, extemporaneously prepared by a compounding pharmacy). Some clinicians recommend adjunctive oral anti-fungals.
Additional treatment options include lamellar keratectomy, amniotic membrane transplant (AMT) and penetrating keratoplasty. While these may sound grim, most patients who develop a Fusarium infection have gained improved visual acuity following treatment.
What should you do if you encounter fungal keratitis? You should first obtain corneal scrapings for culture and analysis before initiating any treatment. You can begin empirical treatment for bacterial keratitis unless you strongly suspect and risk factors suggest fungal keratitis. In that case, institute specific treatments discussed above. Clinicians can report cases to local, state or federal health departments. The CDC's resource phone number is 800-893-0485.
Take the Opportunity
This rash of Fusarium cases doesn't have to be a crisis. We should treat it as an opportunity to remind our patients about safe contact lens wear and care.
To obtain references, please visit www.clspectrum.com/references.asp and click on document #127.
Dr. Semes is an associate professor at the University of Alabama at Birmingham School of Optometry.