Herpetic Keratitis

Herpetic keratitis is a viral infection of the cornea, which is the clear dome-shaped surface at the front of the eye. It is caused by the herpes simplex virus (HSV), typically type 1, and less commonly by the varicella-zoster virus (VZV), which also causes shingles.

Causes and Risk Factors

The herpes simplex virus can infect the cornea through a variety of means, including:

• Direct contact with an infected person's secretions, such as saliva or mucus
• Autoinoculation from an infected area of the body to the eye
• Reactivation of latent virus in the nerve cells surrounding the eye

Risk factors for developing herpetic keratitis include:

• Previous history of herpes simplex infection
• History of atopic disease, such as eczema or asthma
• Use of corticosteroid eye drops
• Immunocompromised state, such as in patients with HIV/AIDS or those taking immunosuppressive medications

Symptoms

The symptoms of herpetic keratitis can vary depending on the severity and location of the infection. Common symptoms include:

• Eye pain or discomfort
• Redness and inflammation of the eye
• Blurred vision
• Sensitivity to light
• Excessive tearing or discharge
• A feeling of having something in the eye

Types of Herpetic Keratitis

There are several types of herpetic keratitis, including:

• Epithelial keratitis: Involves the outer layer of the cornea and is characterized by small, shallow ulcers on the surface of the eye.
• Stromal keratitis: Involves the deeper layers of the cornea and can cause more severe inflammation and scarring.
• Endothelial keratitis: Involves the innermost layer of the cornea and can lead to corneal edema and vision loss.

Diagnosis

The diagnosis of herpetic keratitis is typically made based on a combination of clinical examination, medical history, and laboratory tests. These may include:

• Slit-lamp examination: A specialized microscope used to examine the eye in detail.
• Corneal scraping or biopsy: To collect a sample of cells from the cornea for further testing.
• Viral culture or PCR (polymerase chain reaction) testing: To detect the presence of the herpes simplex virus.

Treatment

The treatment of herpetic keratitis depends on the severity and type of infection. Common treatments include:

• Antiviral medications, such as trifluridine or ganciclovir, to reduce viral replication.
• Corticosteroid eye drops to reduce inflammation, but these should be used with caution and under close supervision due to the risk of worsening the infection.
• Pain management with oral medications or topical anesthetics.
• Supportive care, such as lubricating eye drops and avoiding rubbing the eyes.

Complications

If left untreated or inadequately treated, herpetic keratitis can lead to complications such as:

• Corneal scarring and vision loss.
• Chronic inflammation and recurrent infections.
• Increased risk of secondary bacterial or fungal infections.

Prevention

To reduce the risk of developing herpetic keratitis, it is recommended to:

• Avoid touching the eyes and face.
• Practice good hygiene, such as washing hands frequently.
• Avoid sharing makeup or makeup brushes.
• Get regular eye exams to monitor for any signs of infection.