Corneal Disease

The cornea is the clear window that makes up the front of the eye and lets light into the eye. The cornea also helps focus light so you see clearly; but only when the cornea is clear and smooth can your vision be clear. If the cornea becomes cloudy or warped, your vision will be blurry or distorted.

What eye conditions can affect the cornea?

Astigmatism
Instead of the cornea being perfectly round like a basketball, astigmatism is when the cornea is shaped more like a football than a basketball - longer in one direction than in another. This produces uneven focusing of light as it enters the eye, which results in distorted vision. Astigmatism can be something you’re born with or can be the result of various eye diseases or even surgery to the eye. Often astigmatism is easily corrected with glasses. Until more recently, people with astigmatism have not been able to wear soft contact lenses with much success. But now there are disposable soft contacts even for people with astigmatism. Astigmatism can also be treated with refractive surgery, including LASIK , limbal relaxing incisions, or Toric IOLs.

Keratoconus
Keratoconus is an irregular protrusion of the cornea. It is a degenerative non-inflammatory disorder of the eye in which structural changes within the cornea cause it to thin and change to a more cone-like shape than its normal gradual curve. Keratoconus can cause substantial distortion of vision and decreased vision. It is typically diagnosed in the patient's adolescent years and attains its most severe state in the twenties and thirties. Keratoconus is a little-understood disease with an uncertain cause, and its progression is often unpredictable. It does not lead to blindness, and in most cases, glasses are effective enough to allow patients to continue to function normally. Further progression of the disease may lead to a need for surgery.

Infections
Infections of the cornea are rare, but often they can be blinding. Most people who get corneal infections have identifiable risk factors, such as contact lens wear or blepharitis (inflammation of the eyelids). Sometimes viruses can infect the cornea; often these are minor and are associated with the common cold, but sometimes serious viruses like herpes can infect the cornea. Corneal infections usually produce some scar tissue after they heal. Usually this is off to the side of the cornea and doesn’t affect vision. But scarring in the center part of the cornea can greatly reduce vision, and often requires a corneal transplant to recover vision.

Swelling
Swelling of the cornea occurs in a number of situations. One of the most common is called Fuch’s Corneal Dystrophy. In this disorder, the pump that keeps the cornea dry is broken, and the cornea takes on too much water. The swollen and bloated cornea loses its transparency and becomes cloudy, reducing vision. Another source of swollen corneas is the old-fashioned implants that used to be placed in the eye after cataract surgery back in the 1970s and early 1980s. These implants occasionally cause the cornea to swell up, reducing vision. Eye drops don’t help corneal swelling very much. Most cases of corneal swelling require a corneal transplant.