Fungal Keratitis
What Is Fungal Keratitis?
When fungi enter your cornea, they begin to grow and multiply within the delicate tissue. The infection causes inflammation and can destroy the corneal structure, leading to scarring that blurs or blocks your vision. Unlike bacterial infections, fungal keratitis often develops more slowly but penetrates deeper into the cornea.
The immune response your body mounts against the fungi can also contribute to tissue damage. This makes early detection and specialized antifungal treatment essential to preserve the clarity of your cornea.
Several different types of fungi can infect your cornea, though some are more common than others. Filamentous fungi such as Fusarium and Aspergillus are frequently found in soil and plant material, and they often cause infection after eye trauma involving vegetation.
- Fusarium species, commonly found in soil and plants
- Aspergillus species, present in dust and decaying matter
- Candida species, which may occur in eyes with chronic surface disease
- Other environmental molds that can contaminate contact lens solutions
Fungal keratitis may progress from mild discomfort to severe vision loss if left untreated, though the pace can vary. The longer the infection continues, the deeper the fungi penetrate into your cornea, making treatment more difficult and outcomes less predictable.
We emphasize immediate care because early antifungal therapy offers the best chance of preserving your vision. Delays in diagnosis or treatment can lead to corneal perforation, permanent scarring, or the need for corneal transplantation.
Recognizing the Symptoms of Fungal Keratitis
The earliest symptoms of fungal keratitis may be subtle and easy to overlook. You might notice mild irritation or a feeling that something is in your eye, even when nothing is visible. These initial signs can gradually worsen over days or weeks.
Many patients first become aware of a problem when typical eye discomfort does not improve with rest or over-the-counter drops. If you experience persistent eye symptoms, especially after an injury or while wearing contact lenses, take these immediate steps and schedule an examination promptly.
- Stop wearing contact lenses immediately
- Do not patch the eye
- Do not use leftover steroid drops or someone else's eye drops
- Avoid rubbing the eye
- Seek same-day ophthalmic evaluation, especially after plant trauma or during contact lens wear
As the infection progresses, you may develop significant eye pain that ranges from a dull ache to sharp, stabbing sensations. This discomfort often worsens with eye movement or blinking and may interfere with your daily activities.
- Pain that continues or worsens despite rest
- Throbbing or aching around the eye
- Increased sensitivity when touching near the affected eye
- Discomfort that disrupts sleep or concentration
Fungal keratitis frequently causes blurred or hazy vision as the infection clouds the normally transparent cornea. You might find it difficult to read, drive, or perform tasks that require clear sight.
Some patients describe their vision as looking through a foggy window or experiencing halos around lights. These visual changes indicate that the infection is affecting the optical clarity of your cornea and require urgent attention.
Excessive watering or tearing is common as your eye tries to respond to the infection. You may notice some mucoid or scant discharge, though fungal keratitis typically produces less discharge than bacterial infections.
Redness typically develops around the cornea and can spread across the white part of your eye. While some patients may develop white or yellowish discharge, this is less typical of fungal keratitis, and serious infection can occur even without noticeable purulent discharge.
Many people with fungal keratitis develop photophobia, an uncomfortable sensitivity to light. Bright sunlight, indoor lighting, or even the glow from screens may cause pain or force you to squint or close your eyes.
- Discomfort in normal indoor lighting
- Need to wear sunglasses indoors or outdoors
- Difficulty looking at computer or phone screens
- Headaches triggered by light exposure
A telltale sign of fungal keratitis is a white, gray, or yellowish spot on the surface of your cornea. This lesion represents the area of active infection and may have irregular, feathery edges that may suggest fungal rather than bacterial infection.
Sometimes you can see this spot yourself when looking closely in a mirror, though it is most clearly visible during examination with specialized lighting. The presence of such a spot is a red flag that demands immediate professional evaluation.
Risk Factors and Common Causes
Contact lens wear is one of the leading risk factors for fungal keratitis in many regions, especially when lenses are not properly cleaned or are worn for extended periods. Sleeping in contact lenses or using contaminated lens solution can introduce fungi to your cornea.
- Poor hand hygiene before handling lenses
- Using tap water to rinse lenses or lens cases
- Wearing lenses longer than recommended
- Storing lenses in old or contaminated solution
- Swimming or showering while wearing lenses
If you suspect a corneal infection, discard your current lenses, lens case, and solution immediately. Some clinics may ask you to bring these items for culture testing, so check with your eye care provider about their specific policy.
Injuries involving plant material, such as a tree branch, thorn, or leaf scratching your eye, can introduce fungal spores directly into the cornea. Even minor trauma can create an entry point for infection. In many parts of the world, this vegetative trauma is the dominant cause of fungal keratitis.
Outdoor activities like gardening, farming, or yard work carry a higher risk, particularly when flying debris strikes the eye. We advise wearing protective eyewear during these activities to reduce your risk of traumatic fungal keratitis.
If your immune system is compromised due to conditions like diabetes, HIV, or cancer treatment, you are more vulnerable to fungal infections including keratitis. Immunosuppressive medications can also increase your susceptibility.
A weakened immune response makes it harder for your body to fight off invading fungi, allowing infections to establish and progress more easily. We monitor high-risk patients closely and encourage prompt reporting of any eye symptoms.
Prior corneal surgery, including procedures like LASIK or cataract surgery, can create microscopic changes to the corneal surface that make infection more likely. Chronic conditions such as dry eye syndrome, bullous keratopathy, neurotrophic keratopathy, exposure keratopathy, or eyelid abnormalities may also increase risk.
- Recent corneal transplant or refractive surgery
- Severe dry eye that disrupts the corneal surface
- Eyelid disorders that prevent proper eye closure
- Previous corneal ulcers or scars
- Bandage contact lens use after surgery
Long-term use of corticosteroid eye drops can suppress the local immune defenses in your eye, making it easier for fungi to invade and grow. These medications are sometimes prescribed for inflammation but require careful monitoring. Using steroid eye drops without ophthalmologist direction can significantly worsen undiagnosed microbial keratitis and lead to serious complications.
If fungal keratitis is suspected, reducing or discontinuing steroid drops is typically necessary, as continued use can worsen the infection. In rare situations, steroids may be cautiously considered only after the infection is clearly improving and under close specialist supervision. Any changes to your medication regimen should be made under our supervision to ensure your safety.
How We Diagnose Fungal Keratitis
During your examination, a slit lamp microscope with bright illumination is used to inspect your cornea in detail. The examination looks for characteristic signs such as irregular infiltrates, feathery edges, and satellite lesions that may suggest fungal infection.
The assessment also includes the depth of the infection, the extent of inflammation, and any complications such as increased eye pressure or involvement of deeper eye structures. This thorough evaluation helps determine the severity of your condition and plan appropriate treatment.
To confirm the diagnosis and identify the specific fungus, a corneal scraping may be performed. This procedure involves gently removing a small sample of tissue from the infected area using a sterile instrument after numbing your eye with drops.
- The sample is sent to a laboratory for culture and microscopic analysis
- Culture results typically take several days but guide targeted antifungal therapy
- KOH wet mount, Gram stain, or calcofluor white staining may provide faster preliminary results
- PCR or other molecular tests may be available at some centers
- Multiple scrapings may be needed if initial results are inconclusive
Culture remains an important diagnostic tool, though sensitivity can be limited and turnaround time is often several days. When clinical suspicion for fungal keratitis is high, empiric antifungal therapy may be started before final culture results are available.
In some cases, advanced imaging technologies such as confocal microscopy may be used to examine your cornea at the cellular level. This non-invasive technique can sometimes detect fungal structures directly and assess the depth of infection more precisely.
Optical coherence tomography may also help visualize the layers of your cornea and monitor treatment response. These tools provide valuable information that complements traditional examination and laboratory testing.
Fungal keratitis can look similar to bacterial, viral, or parasitic corneal infections, making accurate diagnosis essential. The appearance of the corneal lesion, medical history, and risk factors are evaluated to differentiate between these causes.
Fungal infections often have a slower onset and distinct appearance with feathery borders and raised lesions. Acanthamoeba keratitis is a key mimic, particularly in contact lens wearers with water exposure, and requires different testing and treatment. Laboratory confirmation through scraping and culture remains the gold standard for distinguishing fungal keratitis from other types of infections.
Treatment Approaches for Fungal Keratitis
The cornerstone of fungal keratitis treatment is topical antifungal eye drops, which deliver medication directly to the infected cornea. Selection of the specific antifungal depends on the type of fungus and the severity of infection.
- Natamycin 5% is commonly first-line for filamentous fungi
- Amphotericin B, usually compounded, is often used for yeast such as Candida
- Topical voriconazole, compounded, may be used as adjunct or alternative in selected cases
- Drops often require compounding and may sting or cause irritation
Treatment usually begins with frequent application, often every one to two hours initially, to achieve adequate drug levels in the cornea. You will need to maintain this intensive schedule for several days before the frequency may be gradually reduced based on your response.
In addition to antifungal medications, supportive treatments help manage symptoms and prevent complications during your recovery.
- Cycloplegic drops may be used for pain and photophobia when appropriate
- Oral analgesics as needed for discomfort
- Intraocular pressure-lowering therapy if pressure rises
- Careful epithelial debridement in select cases to improve drug penetration, performed by your clinician
- Avoidance of topical anesthetic misuse; no take-home anesthetic drops are provided
When the infection extends deep into the cornea, is large, approaches the limbus or sclera, threatens to spread to other parts of your eye, or occurs in immunocompromised patients, oral antifungal medications may be considered in addition to eye drops. These systemic medications help fight the infection from within and may be beneficial in selected severe cases or for specific organisms.
- Oral voriconazole or fluconazole may be prescribed based on the fungal species and clinical scenario
- Blood tests monitor for potential side effects affecting the liver; azoles also have significant drug interactions and may affect heart rhythm
- Monitoring is individualized based on the specific medication and your health status
- Duration of oral treatment depends on infection severity and response
Treating fungal keratitis requires patience and commitment, as antifungal therapy typically continues for several weeks to months. The infection clears more slowly than bacterial keratitis, and premature discontinuation can lead to recurrence.
Progress is monitored closely with frequent follow-up appointments, and treatment intensity is adjusted based on how your cornea is healing. Even when symptoms improve, medication often continues at a reduced frequency to ensure complete eradication of the fungi. Antifungal drops can sometimes cause epithelial toxicity or inflammation, and adherence to the intensive schedule can be challenging, so close follow-up and communication are essential. Never stop therapy without clinician direction.
If antifungal medications fail to control the infection or if the cornea begins to thin dangerously, surgical intervention may become necessary. A therapeutic keratoplasty, which removes infected tissue, may be performed during active infection when medical therapy is failing, or in cases of perforation or impending perforation.
In some situations, amniotic membrane grafts may be applied to support healing, or tissue adhesive with a bandage contact lens may be used as a temporizing measure for impending perforation. Other procedures may be performed to stabilize your cornea. Intrastromal or intracameral antifungal injections are considered in selected refractory cases at some centers.
When fungal keratitis causes extensive corneal scarring or perforation, a corneal transplant may be your best option for restoring vision. This procedure replaces your damaged cornea with healthy donor tissue.
Corneal transplantation may be required during active infection in emergency situations when the structural integrity of your eye is at risk, or after the infection has been controlled but has left permanent damage. Long-term antifungal therapy and careful monitoring continue even after successful transplantation to prevent recurrence.
Recovery, Aftercare, and Prevention
Recovery from fungal keratitis is often a gradual process that unfolds over weeks to months. You may notice that symptoms like pain and redness improve before your vision fully clears, as corneal healing takes time.
Some degree of corneal scarring is common even with successful treatment, which can result in permanent changes to your vision. We work with you to manage expectations and explore options such as corrective lenses or additional procedures to optimize your visual outcome after healing.
Regular follow-up visits are crucial during and after treatment for fungal keratitis. Initially, you may need to be seen every few days to assess your response to therapy and watch for complications.
- Frequent examinations in the first weeks of treatment
- Gradual spacing of appointments as healing progresses
- Long-term monitoring for recurrence or late complications
- Adjustments to medications based on clinical findings
If you wore contact lenses before developing fungal keratitis, we will provide detailed guidance on safe lens practices to prevent future infections. Many patients can eventually return to lens wear with strict adherence to hygiene protocols.
Always wash your hands thoroughly before handling lenses, use only fresh sterile solution, and replace your lens case regularly. Never rinse lenses with tap water or wear them while swimming, and follow the recommended replacement schedule for your specific lens type.
Preventing eye trauma, especially from vegetation or soil, is essential for reducing your risk of fungal keratitis. We recommend wearing protective eyewear such as safety glasses or goggles when gardening, doing yard work, or engaging in activities with flying debris.
- Use safety glasses during outdoor work and sports
- Wear goggles when using power tools or equipment
- Protect your eyes from plant branches and thorns
- Irrigate your eye with sterile saline if available, otherwise clean running water, if debris enters it; do not rub the eye
- Seek prompt evaluation after any eye injury
Certain symptoms warrant immediate emergency evaluation, even if you are already being treated for fungal keratitis. Sudden worsening of pain, rapid vision loss, or signs that your eye is perforating require urgent intervention.
Contact our office or go to an emergency department right away if you experience sudden severe pain, a significant decrease in vision, increasing redness or discharge despite treatment, new floaters or flashes with worsening photophobia and headache or nausea, increasing corneal whitening or thinning, a visible fluid leak, or if your pupil appears irregular or your eye feels abnormally soft. These warning signs may indicate serious complications that need immediate attention.
Frequently Asked Questions
Fungal keratitis typically does not spread from one eye to the other through the air or casual contact. However, if you touch your infected eye and then touch your other eye without washing your hands, you could theoretically transfer fungi. We advise practicing good hand hygiene and avoiding touching either eye unnecessarily during treatment to minimize any risk of spread.
Fungal keratitis is generally not contagious to other people through normal daily interactions. The fungi causing your infection usually require direct introduction into the cornea through trauma or contaminated contact lenses. You do not need to isolate yourself from family members, but we do recommend not sharing towels, eye drops, or contact lens supplies with anyone else.
The impact on your vision depends on how quickly the infection is diagnosed and treated, as well as its severity and location on the cornea. With prompt antifungal therapy, many patients recover good vision, though some permanent scarring and visual changes are possible. Delayed treatment or very aggressive infections carry a higher risk of vision loss, which is why we stress the importance of seeking care immediately when symptoms appear.
Many patients wonder whether they can safely return to contact lens wear after recovering from fungal keratitis. The answer depends on the extent of corneal healing and your ability to follow strict hygiene practices. We generally recommend waiting until your cornea has fully healed and any scarring has stabilized, which may take several months, before considering contact lenses again with very careful supervision.
While both conditions involve corneal infection, fungal keratitis typically progresses more slowly than bacterial keratitis and often penetrates deeper into the corneal tissue. The appearance under the microscope also differs, with fungal infections showing feathery borders and satellite lesions. Treatment differs significantly as well, since antifungal medications are required for fungi while antibiotics treat bacterial infections, making accurate diagnosis essential for successful outcomes.
Getting Help for Fungal Keratitis
If you experience eye pain, redness, vision changes, or any symptoms suggesting fungal keratitis, prompt evaluation is essential. Early diagnosis and treatment offer the best chance of preserving your vision and preventing serious complications. We are here to provide expert care and guide you through every step of diagnosis, treatment, and recovery.