What is Fungal keratitis?
Fungal keratitis (FK) is a significant eye infection, often triggered by factors like eye trauma, corticosteroid use, or contact lens wear. Diagnosis involves polymerase chain reaction, direct microscopic examination, and cultures.
FK is treated with topical natamycin and voriconazole, with surgery sometimes necessary. It comprises 40% to 50% of all microbial keratitis cases, posing a threat of severe vision loss if untreated. Over 100 fungal species can cause FK, influenced by personal risk factors and environmental conditions.
Diagnosis can be challenging, requiring a high index of suspicion, especially with specific risk factors. Treatment is difficult due to poor penetration of antifungal agents into the cornea.
Symptoms
Treatments
Precautions
Symptoms
Fungal Keratitis symptoms include
- Blurring of vision
- Pain
- Redness
- Discharge
- Blepharospasm
- Signs of inflammation in the anterior chamber with hypopyon may be present.
- Cases caused by filamentous fungi may involve:
- History of trauma with vegetative matter
- Ulcer characterized by:
- Elevated firm slough
- Hyphate lines extending beyond the edge of the central ulcer
- Feathery satellite stromal lesions
- FK due to yeast fungi may resemble bacterial keratitis symptoms but with a slower progression.
- Accurately predicting the causative fungal genus or species responsible for FK can be challenging and inaccurate based solely on clinical presentation.
Treatments
Treatments for Fungal Keratitis
- Topical antifungal agents: Natamycin 5%, Amphotericin B 0.15-0.3%, Voriconazole 1%, Econazole 1%, Itraconazole 1%, Miconazole 1%
- Subconjunctival injections of antifungal agents for severe cases
- Systemic treatment: Intravenous amphotericin B, Oral itraconazole or fluconazole
- Decisions to continue therapy based on biomicroscopic findings.
- Therapeutic penetrating and lamellar keratoplasty
- Corneal collagen cross-linking
- Tectonic or therapeutic keratoplasty for corneal perforation
- Intravitreal injections or vitrectomy for endophthalmitis
- Enucleation as a last resort
- Keratoplasty for corneal scarring post-healing.
Precautions
- Geographic Awareness: Acknowledge variations in FK prevalence and causative organisms based on location, climate, and socioeconomic factors.
- Risk Factor Awareness: Understand how trauma, contact lens use, ocular surface disease, and topical steroids predispose individuals to FK.
- Hygiene Practices: Stress the importance of personal hygiene, including proper handwashing and avoiding overnight contact lens wear, to reduce fungal infection risk.
- Contact Lens Safety: Educate contact lens users about safe practices to minimize the risk of FK, such as avoiding overnight wear and proper cleaning methods.
- Product Monitoring: Continuously monitor contact lens solutions to prevent outbreaks like the Fusarium keratitis case linked to a specific brand.
- Outdoor Activity Precautions: Advise precautions, especially for young males engaged in outdoor activities, to prevent trauma and FK risk.
- Prompt Diagnosis and Treatment: Encourage early medical attention for FK symptoms to prevent complications and vision loss.
- Differentiation: Recognize the challenge of distinguishing FK from bacterial keratitis, necessitating thorough evaluation and diagnosis.
Types of Fungal Keratitis
Before the Surgery
During the Surgery
After the Surgery
Before the Surgery
How you prepare for Fungal Keratitis Surgery
- Patient Education: Educate about contact lens hygiene and symptoms, emphasizing immediate medical attention if symptoms arise.
- Regular Check-Ups: Encourage regular eye examinations for contact lens wearers.
- Interprofessional Approach: Facilitate teamwork for prompt referral to ophthalmologists.
- Nurse Counseling: Nurses should educate, schedule follow-ups, and ensure team communication.
- Pharmacist Support: Review medication details and administration methods.
- Close Monitoring: Monitor closely for treatment adjustments as needed.
- Consider Patient Factors: Understand patient health and immune status for tailored care.
During the Surgery
- Antifungal Selection: Choose appropriate antifungal agents based on infection type and severity for topical, subconjunctival, or systemic administration.
- Intraoperative Assessment: Continuously evaluate intraoperative findings like changes in infiltrate size, satellite lesions, and inflammation to guide treatment decisions.
- Review Treatment Data: Consider recent clinical trial data to inform treatment choices, particularly regarding natamycin versus voriconazole.
- Surgical Planning: Prepare for potential interventions such as penetrating or lamellar keratoplasty, corneal collagen cross-linking, or vitrectomy for severe cases.
- Emergency Readiness: Ensure readiness for emergency procedures like keratoplasty or intravitreal injections in cases of perforation or endophthalmitis.
- Patient Communication: Maintain clear communication with patients about the surgery, potential risks, and expected outcomes to ease concerns and support decision-making.
After the Surgery
- Patient Education: Continue educating patients on contact lens hygiene and post-surgery symptoms.
- Follow-Up: Schedule regular appointments to monitor recovery and address any concerns.
- Symptom Monitoring: Instruct patients to report any unusual symptoms promptly.
- Medication Adherence: Stress the importance of following prescribed medication regimens.
- Recovery Oversight: Monitor closely for complications like infection recurrence or graft rejection.
- Interprofessional Collaboration: Maintain communication among healthcare team members.
- Patient Support: Offer ongoing counseling and support for patient concerns.
Fungal Keratitis FAQs
How is fungal keratitis diagnosed?
How is fungal keratitis treated?
How do you prevent fungal keratitis?
What puts people at risk for fungal keratitis?
Risks for developing fungal keratitis include
- Recent eye trauma, particularly involving plants (for example, thorns or sticks)
- Underlying eye disease
- Weakened immune system
- Contact lens use
In 2006, CDC investigated an outbreak of Fusarium keratitis. The infections were associated with a specific type of contact lens solution, which was withdrawn from the market.