|WHAT YOU NEED TO KNOW ABOUT FUSARIUM KERATITIS
With the recent incidence of Fusarium fungal-based corneal ulcers in the United States, there are several commonly asked questions pertaining to the severity, incidence and management of this problem. Contactlenses.org will endeavor to provide valuable information to those most commonly asked questions to this important eye-related complication.
1) WHAT IS FUSARIUM?
There are over 100,000 species in the fungus (i.e., molds and yeasts) kingdom with over 70 that may infect the front surface of the eye or the cornea. Fusarium, Aspergillus (both fungi), and Candida (a yeast) cause the great majority of fungal cornea infections. Fusarium solani is the species implicated in the recent incidence of contact lens wearers experiencing a fungal keratitis. Fusarium is common for the warmer climates and the agricultural community where it is commonly found in organic matter such as soil and plants and represents normal flora for rice, beans and soybeans. The resulting infection can not be transmitted from person to person.
2) WHAT IS MICROBIAL KERATITIS? (I.E., CORNEAL ULCER)
A microbial keratitis, also termed “corneal ulcer,” is a severe infection of the cornea which, after treatment, can often result in a scar in the region where it was located. If infection was located at or near the center of the cornea, this scar can result in reduced vision. There has to be loss of some of the cells of the outer layer of the cornea (termed the epithelium) for the offending organism to enter. Microbial keratitis has a very low incidence with contact lens wearers, occurring in 4 out of every 10,000 individuals with a daily wear schedule and 21 of 10,000 wearers in extended wear. Often, these infections are caused by bacteria. Fungal keratitis is extremely rare, particularly in the northern regions. The more typical case would be a southern farmer who has experienced trauma to his eye and via plant matter from his hands, the fungal organism came in contact with the eye. It also has a tendency to occur with people who have a suppressed immune system as well as those individuals taking topical corticosteroids. Until now, very few cases of fungal keratitis have been reported with contact lens wearers. The responsible organism in these cases has been Fusarium solani and most of the cases have involved individuals wearing their lenses extended wear.
3) WHY IS THERE A PROBLEM WITH FUNGAL KERATITIS TODAY?
As of February, 2006, 39 cases of fungal keratitis (all Fusarium) were reported with contact lens wearers in Singapore over a 10 month period. As of April 27th, 2006, the Center for Disease Control (CDC) in Atlanta is investigating 228 reports of possible Fusarium keratitis in 29 states. Of these reports, CDC and state/local health departments have identified 84 confirmed and possible cases; 98 remain under investigation and 46 have been excluded. The majority of these patients have not yet been interviewed; however, of the first 58 patients who have been contacted, 56 were contact lens wearers. The care system entitled “ReNu® with MoistureLoc™” has been found to be associated with a disproportionately high percentage of the cases; further investigation into this issue is currently being conducted. Bausch & Lomb, has stopped shipment of it in the United States and practitioners have been asked to stop dispensing it; stores, likewise, have removed it from their shelves.
4) HOW DO I KNOW IF I HAVE A FUNGAL KERATITIS?
As with any microbial keratitis, there are several symptoms that could tip you off that you may have a fungal keratitis. These include red, irritated eyes (or eye) with associated pain in and around the eyes, sudden fuzzy or blurred vision, excessive tearing of the eyes and increased sensitivity to light. It is vital that you see your eye care practitioner immediately if you have these symptoms. It mimics more common forms of microbial keratitis; therefore, your eye care practitioner may initiate treatment with an antibiotic until laboratory microbiology results (often through a culture or tissue biopsy) are received. This process can take up to two weeks. If confirmed, topical and/or oral antifungal medications are often the mode of treatment. In approximately 25 – 35% of cases, a corneal transplant is necessary.
5) IS CONTACT LENS WEAR UNSAFE?
Please keep in mind that contact lenses remain a very safe and effective vision correction option. As contact lenses are medical devices, following your eye care practitioner’s lens wear and care guidelines will even further minimize the risk of this serious eye infection. Several important recommendations are as follows:
Unless you are wearing daily disposable lenses (i.e., lenses thrown away every night), you should remove the lenses, clean them in the palm of the hand with your fingers and soak them in the recommended disinfecting solution.
Always wash your hands prior to handling your lenses
Only use the solution regimen recommended to you by your eye care practitioner
Always replace your disinfecting solution every day – even if you are not using your lenses every day – to reduce the risk of contamination
Replace your lenses in accordance to the schedule provided by your eye care practitioner
Do not wear your lenses overnight unless recommended by your eye care practitioner. If extended wear is recommended, do not exceed the recommended number of nights of continuous wear. It has been found that microbial keratitis occurs least when a daily wear schedule is employed. Likewise, the use of gas permeable (GP) lenses also results in a very low incidence of microbial keratitis.
As the lens case can easily be contaminated and transfer these organisms to the contact lens, be sure to replace your lens case at least every three months.
Immediately stop wearing your lenses and call your eye care practitioner if you experience pain, severe redness, sudden blurred vision, excessive light sensitivity and tearing.
Only wear contact lenses that have been prescribed for you by your eye care practitioner.
6) WHERE CAN I OBTAIN ADDITIONAL INFORMATION?
Two good sources for updated information are:
Centers for Disease Control (CDC) – http://www.cdc.gov/mmwr/
American Optometric Association (AOA) – http://www.aoa.org
This document was downloaded from www.contactlenses.org.
Copyright 2006-2013 Contact Lens Manufacturers Association