Corneal Diseases and Trauma

Corneal Diseases and Trauma

What is the cornea?

The cornea is the outermost layer of the center of the eye. It is dome-shaped and circular, covering the entirety of the pupil and the colored iris. The cornea ends at the edges of the iris, and does not cover the white of the eye, which is known as the sclera.

Along with the lens, the cornea helps refocus light passing through the pupil. It also serves the important purpose of protecting the eye from germs, dust and other harmful particles.

Which diseases affect the cornea?

The cornea can be affected by a number of conditions. A type of disease called "corneal dystrophy" causes clouding in the corneas of both eyes simultaneously. The most common corneal dystrophies include:

  • Keratoconus - a progressive disease in which the cornea becomes gradually thinner and more cone-shaped. Keratoconus can lead to severe visual distortion, scarring, swelling and vision loss.
  • Fuch's Dystrophy - a gradual breaking down of the cornea's innermost cells. As these cells disappear, the eye loses its ability to remove water from the cornea's middle layer, causing the cornea to swell. This can result in warped or hazy vision, as well as small blisters on the corneal surface. More common in women, Fuch's dystrophy begins to appear between ages 30 to 40, but the condition usually doesn't affect vision until 20 years later.

Like all corneal dystrophies, keratoconus and Fuch's dystrophy affect the cornea without causing inflammation. There are, however, many inflammatory diseases that affect the cornea, including:

  • Keratitis - an inflammation of the cornea due to bacterial or fungal infection. These organisms can enter the eye after an injury or as a result of improper contact lens hygiene. Symptoms of keratitis include reduced vision, discharge from the eye and severe pain.
  • Herpes of the eye - the primary cause is the non-sexual form of herpes, though sexual herpes is also known to affect the eye. Either virus can produce sores on the surface of the cornea, which can then spread deeper into the eye.
  • Shingles - the occurrence of the chicken pox virus can cause ocular inflammation, lesions or blisters on the cornea, along with severe nerve pain.

Certain traumatic events can scar the cornea, causing cloudiness and loss of vision. These include, but are not limited to, projectiles such as Airsoft bullets, lacerations, blunt trauma and burns.

What are the treatments for corneal diseases and trauma?

A corneal transplant can resolve most cases of corneal disease and trauma. For select patients, a laser treatment called PTK is available instead of surgery.

Learn more about corneal transplant at Temple.

To schedule an appointment with a Temple ophthalmologist, click here or call 1-800-TEMPLE-MED (1-800-836-7536).