Fungal Keratitis, or keratomycosis, is an inflammation of the eye’s cornea, or keratitis, which results from a fungal infection. Other kinds of infectious keratitis include bacterial and viral. The incidence of fungal keratitis in the US varies depending on geographical location. In New York, about two percent of kertitis cases are fungal whereas in Florida, about 35 percent are. The most common species causing fungal keratitis in the US is Fusarium. In northern states, however, the most common species are Aspergillus and Candida.
Symptoms of fungal keratitis include:
- Blurred vision
- Red and painful eye
- Increased sensitivity to light
- Excessive tearing or discharge
Ophthalmologists, who should be contacted immediately when these listed symptoms appear, will likely perform a slit lamp examination. A positive diagnosis for fungal keratitis will reveal a corneal ulcer with lesions in the surrounding cornea. There may also be a pus-like fluid in the front chamber of the eye that could subsequently cause endophthalmitis as it extends to the posterior segment. If an ophthalmologist is not consulted in time, this endophthalmitis, or inflammation of tissues inside the eye, can lead to the destruction of the eye.
If the ophthalmologist suspects the onset of the condition, a definitive diagnosis is established about a week after securing a culture from a corneal scraping. Quicker results can now be obtained through a polymerase chain reaction (PCR) test.
The usual way fungal keratitis is precipitated is by trauma with an organic or vegetable matter. It typically occurs through a thorn injury or in agriculture workers who encounter trauma with a wheat plant while cutting the harvest. The fungus becomes implanted directly in the cornea, where it grows and propagates, involving the stromal layers, eventually breaking through the descemet’s membrane into the anterior chamber. The symptoms of fungal keratitis appear a few days or weeks later.
In April, 2006, the FDA notified the public that there had been an increase in reports of fusarium keratitis by contact lens wearers using Bausch and Lomb’s ReNu with MoistureLoc products. Bausch & Lomb subsequently recalled the products. It should also be noted that every year microbial keratitis affects four to 21 per 10,000 contact lens wearers in the US each year, depending on whether the lenses are used overnight. Additional BLOG about the connection between fusarium keratitis and ReNu can be seen at the following websites –
Agricultural workers while harvesting and other people at risk for contracting fungal keratitis should wear broad protective glasses with side shields. Once the condition is diagnosed, however, empirical therapy is required at once. For those with filamentous fungal infection, the drug of choice is natamycin ophthalmic suspension. For those with Candida infection of the cornea, fluconazole ophthalmic solution is recommended. For non-responding cases, amphotericin B eye drops may be required.
Because of the slow growth of the fungus, the infection usually takes a long time to heal. For patients in whom corneal perforation has taken place, corneal transplantation may be needed.
Additional blogs about fungal keratitis include – http://www.aoa.org/x5119.xml