Introduction  

Herpes simplex is a virus that can lead to the inflammation of the front protective lining of the eyeball, the cornea. This kind of viral infection is known as Herpes keratitis.  

Epithelial keratitis is the mild and most common form of this viral infection. It affects the outer layer of the cornea. 

Stroma keratitis is an advanced form of the disease. It affects the middle and deeper layers of the cornea. It can lead to severe corneal damage resulting in loss of vision and blindness.

HSV is a significant cause of corneal blindness throughout the world. It is the leading cause of infectious blindness in the West, and a significant cause of blindness linked to corneal damage in the US.

The good news is that the eye disease can be controlled and the corneal damage minimized with prompt treatment.

Also Known As

  • Eye herpes
  • Ocular herpes
     

Sub-Types

There are two primary forms of Herpes simplex virus (HSV):

  • Type I herpes - Primarily infects the face and is the most common form of the virus.
  • Type II herpes - Usually affects the genitals since it is a sexually transmitted form of herpes.
     

Causes and Risk Factors

Both Type I and Type II herpes can cause infection by spreading to the cornea. The virus can transfer to the cornea from an active lesion such as a blister or cold sore through touch.

Type I herpes is the most contagious form of HSV. It is often transmitted by skin contact with an infected person. 

A vast majority of people are exposed to Type I herpes during childhood. The viral infection often goes unnoticed because it may not present any symptoms.

After the initial attack, the virus remains inactive in the body. It could be living in the skin or eye tissues. At times, the virus can be reactivated causing it to spread to the cornea.

Risk factors
The virus can be reactivated by:

  • Weakened immune system
  • Sun exposure such as tanning beds
  • Other UV light exposure
  • Exposure to cold wind
  • Stress
  • Body or eye injury 
  • Surgery
  • Menstruation
  • Fever
  • Certain medications
     

Signs & Symptoms

In most cases, only one eye is affected. Sometimes both eyes are infected.
Herpes keratitis symptoms may include:

  • Increased sensitivity to light
  • Blurred vision
  • Eye pain
  • Excess tearing
  • Swelling around the eye
  • A rash
  • A red eye
  • An eye discharge

A person who experiences any of the symptoms should seek urgent medical attention. People who wear contacts should remove them and not use them until they have recovered.

Diagnosis

The eye care professional reviews the patient’s medical history, symptoms and performs an eye examination. It may include:

  • Visual acuity test 
  • Intraocular pressure exam
  • Dilated fundus exam 
  • Motility test 
  • External and anterior segment examination 
  • Slit lamp examination 
  • Fluorescein eye stain eye test

He/she may also do a culture or other laboratory analysis for a specific diagnosis.
 

Treatment 

Treatment is aimed at controlling the virus and minimizing the risk of complications.

Medical Treatment

Treatment depends on the severity of the eye disease.
The eye doctor can recommend topical antiviral drops, ointment or oral antiviral drugs for epithelial keratitis. He/she may prescribe antiviral therapy and steroid eye drops for stromal keratitis. 

At times, the doctor may apply numbing eye drops and use a cotton swab to brush the corneal surface to remove infected and damaged cells. This procedure is called debridement and may help speed the healing process.

Surgical Treatment

In severe cases, the patient may need surgery to restore vision.
Where corneal damage is extensive and causes severe loss of vision, keratoplasty (corneal transplant) may be necessary.

Prognosis/Long-term outlook

Once herpes is in the body it cannot be eliminated; there is no cure for the virus. 
Many outbreaks of the disease can damage the cornea and lead to complications including:

  • Corneal ulcers
  • Corneal scars
  • Perforation of the cornea
  • Numbing of the corneal surface
  • Glaucoma
  • Bacterial or fungal infections
  • Irreversible loss of vision

If diagnosed early and managed well a patient can have a favorable prognosis.

Prevention/Follow Up

Some measures can help prevent outbreaks:

  • Maintaining good hygiene
  • Using protective gear for hazardous work and sports
  • Avoid touching the eyes if one has an active blister or cold sore
  • Stop using contacts if one experiences frequent outbreaks
  • Consult an eye doctor at once in case of the above symptoms