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What is Keratoconus?

Tricia Christensen
Tricia Christensen
Tricia Christensen
Tricia Christensen

Keratoconus is a medical condition that results in gradual changes in vision and in shape of the eye. Most often beginning in adolescence, this degenerative illness occurs slowly and may not at first be diagnosed. Diagnosis is important, however, since over time mere corrective measures like using contact lenses may not do enough to correct vision, and some people with keratoconus will require corneal transplant.

Little is known about the causes of keratoconus. Some people, like those with Down syndrome are at an increased risk for this condition. Yet others may have no other medical conditions and still get it. There has been some speculation that people who routinely rub their eyes may be more at risk, and eye-rubbing behavior in children should be discouraged.

Keratoconus causes gradual changes in vision and eye shape.
Keratoconus causes gradual changes in vision and eye shape.

What occurs with keratoconus is that the cornea begins to stretch and get thinner, and this results in the eye having a slight protrusion in front that is shaped like a cone. The change in the cornea and the shape of the eye results in differences in the way the eye perceives light, and vision becomes blurry, which is called astigmatism. Distances become harder to see and nearsightedness or myopia is usually present too.

Soft contact lenses can be worn to treat mild cases of keratoconus.
Soft contact lenses can be worn to treat mild cases of keratoconus.

Common symptoms of this condition include, as mentioned, nearsightedness and blurred vision. People may also have impaired night vision, corneal rupture flooding the eye with extra fluid, and headaches. Another typical symptom is that many peoples’ eyes become sensitive to light.

When diagnosed in the early stages, keratoconus is usually treated with contact lenses of varying types. Rigid lenses may be preferred because they can help flatten out eye irregularities, but these may be uncomfortable to wear for some. There are some combination rigid/soft lenses that prove a better solution. For some people, though, the cornea may become too damaged and vision may be impaired even with the use of lenses. In these cases, corneal transplant may be considered to replace the thinned and damaged corneas. About 8-10% of all corneal transplants are to correct the damage caused by this condition.

There are other treatments under investigation including collagen cross-linking, which is a way of arresting corneal thinning. This treatment may or may not become standard, and other eye surgeries might be preferred at a later point. Things like LASIK are not preferred, since they tend not to work and don’t address underlying keratoconus. Those undergoing LASIK should verify that vision problems don’t stem from this illness because if they do, the procedure is not useful.

It is not difficult to diagnose this eye disease, but it may sometimes be missed in early stages. If symptoms above fit, people should ask optometrists or ophthalmologists about looking for this condition, particularly if onset of symptoms occurs in teen years. Another thing that people should tell doctors is if there are other people in the family with keratoconus. There exists some evidence that the condition may run in families even though exact pattern of inheritance or prevalence is not known.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...
Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...

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    • Keratoconus causes gradual changes in vision and eye shape.
      By: blueringmedia
      Keratoconus causes gradual changes in vision and eye shape.
    • Soft contact lenses can be worn to treat mild cases of keratoconus.
      By: revers_jr
      Soft contact lenses can be worn to treat mild cases of keratoconus.