Infectious keratitis (IK)

Infectious keratitis is an infection of the cornea also known as infectious corneal ulcer or corneal opacity. Infectious keratitis can be classified as microbial keratitis (bacteria, fungi or parasites), or viral keratitis (herpes viruses).

Infectious keratitis is an inflammation of the cornea (the clear dome-shaped surface at the front of the eye) caused by a bacterial, viral, fungal, or parasitic infection.

Here is an overview: Types: 1. Bacterial keratitis (most common)

2. Viral keratitis (e.g., herpes simplex, herpes zoster)

3. Fungal keratitis (e.g., candida, fusarium)

4. Parasitic keratitis (e.g., acanthamoeba)

Causes: 1. Contact lens use (especially improper hygiene) 2. Eye trauma or injury 3. Contaminated water or soil exposure 4. Poor eye hygiene 5. Weakened immune system

Symptoms: 1. Eye pain or discomfort 2. Redness and inflammation 3. Blurred vision 4. Sensitivity to light 5. Discharge or pus 6. Eye swelling

Treatment: 1. Antibacterial, antiviral, antifungal, or antiparasitic medications

2. Proper Contact lens removal and hygiene

3. Corneal scraping or biopsy for diagnosis

4. Pain management

5. In some cases, corneal transplant

6. Phototherapy, specifically Photodynamic Therapy (PDT) and Rose Bengal Photodynamic Antimicrobial Therapy (RB-PDAT), has emerged as a promising treatment option for infectious keratitis.

Mechanism: 1. Photosensitizer (e.g., Rose Bengal) is applied to the affected area. 2. Light radiation (specific wavelength) activates the photosensitizer. 3. Reactive oxygen species are produced, killing microbial cells. Benefits: 1. Broad-spectrum antimicrobial activity 2. Reduced risk of antibiotic resistance 3. Minimally invasive 4. Potential to preserve vision Studies have shown RB-PDAT to be effective against various microorganisms, including: 1. Bacteria (e.g., Pseudomonas, Staphylococcus) 2. Fungi (e.g., Candida, Fusarium) 3. Parasites (e.g., Acanthamoeba)

While phototherapy shows promise, please note that : 1. It's often used as an adjunct to conventional treatments (antibiotics, antifungals). 2. More research is needed to fully understand its efficacy and safety. 3. Expertise and specialized equipment are required for administration.

Prevention: 1. Practice good eye hygiene 2. Avoid sharing contact lenses or solution 3. Wear protective eyewear during activities 4. Avoid touching your eyes 5. Regular eye exams.

PROMPT medical attention is essential to prevent complications and vision loss.

Author

Paddy Kalish OD, JD and B.Arch