Corneal Clouding

Clouding of the cornea, whether from external or internal sources, can mean partial or total loss of sight, depending on the severity of damage. A normal, undamaged cornea is necessary for full vision. When the cornea becomes cloudy, similar to the frosting of glass, there are various methods to correct or restore vision. When the cloudiness is on the surface of the cornea, the top layers can be shaved off with a blade or a laser. When deeper layers of the cornea are involved, it may require replacement. Cornea transplants, using tissue from donated eyes, have been successful at treating this condition. Approximately 40,000 corneal transplants are performed in the United States each year.

There are many reasons why the normal, clear cornea may be cloudy, resulting in loss of vision in one of both eyes:

• Congenital corneal clouding
• Eye trauma
• Eye infections
• Corneal dystrophies

Congenital Corneal Clouding

Although rare, sometimes the cornea is clouded at birth. Cornea transplants are necessary soon after birth — preferably before three months of age — to reduce the possibility of amblyopia (lazy eye).

Corneal Injuries

Corneal clouding may follow penetrating or blunt trauma to the eyes. Chemical burns may also severely impair vision by destroying corneal tissue.

Corneal Infections

Infections, such as from herpes simplex virus, bacteria fungi and parasites, may cause corneal ulcers which later heal by forming scar tissue and thus cloud the cornea.

Corneal Dystrophies

A corneal dystrophy is an abnormality of a specific part of the cornea that leads to corneal clouding. It may occur early in life, but is usually seen between the ages of 20 and 50. The dystrophy most commonly requiring a corneal transplant is Fuchs' dystrophy, a condition often found in older adults.