An eye fungal infection, known as fungal keratitis, is an infection of the cornea caused by a fungus. The cornea is the transparent, dome-shaped front part of the eye that covers the iris and pupil, playing a role in focusing light. While serious, fungal keratitis is relatively uncommon globally, affecting an estimated one million people each year. Common fungal species responsible for these infections include Fusarium, Aspergillus, and Candida.
Causes and Risk Factors
Fungal infections of the eye frequently arise from direct trauma to the cornea, particularly injuries involving plant matter. For instance, being struck in the eye by a tree branch or a thorn can introduce fungi directly onto the eye’s surface. Fusarium species, commonly found in soil, water, and plants worldwide, are a frequent cause of such infections, especially in warmer climates.
Improper contact lens hygiene is another significant contributor to fungal keratitis. Wearing contact lenses for extended periods, failing to clean them adequately, or using contaminated lens solutions can create an environment conducive to fungal growth and infection. Individuals with a compromised immune system or those who have recently undergone eye surgery may also face increased susceptibility to these infections.
Common Symptoms
Individuals with fungal keratitis often report symptoms that develop over five to ten days. Eye pain is common, and the affected eye often exhibits significant redness, indicating inflammation.
Vision may become blurred as the infection affects the cornea, impacting its clarity. Sensitivity to light, known as photophobia, is another common symptom, causing discomfort in bright environments. Patients might also observe excessive tearing or a discharge from the infected eye. While these symptoms indicate an issue, they can overlap with those of other eye infections, necessitating professional medical evaluation for an accurate diagnosis.
The Diagnostic Process
Diagnosing fungal keratitis requires a visit to an ophthalmologist, a medical doctor specializing in eye care. The examination begins with a thorough assessment of the eye using a slit lamp, a specialized microscope that allows the doctor to view the cornea and other ocular structures. This visual inspection helps identify characteristic signs of infection, such as specific patterns of corneal infiltration.
After the initial examination, the ophthalmologist takes a tissue sample from the affected cornea, a procedure known as a corneal scraping. This sample is sent to a laboratory for analysis, including direct microscopic examination using various stains to detect fungal elements. The sample is also cultured on specialized media to grow and identify the specific type of fungus causing the infection.
Available Treatments
Treatment for fungal keratitis primarily involves antifungal medication, often administered through intensive eye drops. Natamycin is a widely used first-line topical treatment, particularly effective against filamentous fungi like Fusarium. Amphotericin B eye drops are another option, often considered for infections caused by yeasts such as Candida. Voriconazole, a broad-spectrum antifungal, is also utilized for its effectiveness against various fungal species.
In addition to eye drops, oral antifungal medications, such as voriconazole or itraconazole, may be prescribed, especially in more severe cases or when there is concern about deeper infection. Adhering strictly to the prescribed treatment regimen is important, as these infections can be challenging to resolve and often require weeks to months of medication. If medical therapy proves ineffective or if the cornea sustains significant damage, a surgical procedure like a corneal transplant may become necessary to restore vision.