Location: Eye Health >> Eye Conditions & Diseases >> Keratoconus
Keratoconus is a non-inflammatory condition of the cornea in which
there is progressive central thinning of the cornea changing it from dome-shaped
to cone-shaped. Keratoconus comes from the Greek word meaning Conical
Cornea (Cone shaped- Cornea). The cornea is the clear outer covering of
the front of the eye that provides most of the eyes' optical power. Therefore,
abnormalities of the cornea can significantly affect the way we see the
world. Keratoconus is not a blinding disorder, but it is a progressive
condition, usually beginning in the teens or 20s, but often stabilizing
after a few years. It usually occurs in both eyes.
The cause of keratoconus is poorly understood, but it runs in families
and may have genetic origins; about 7 percent of people with keratoconus
have a family history of the disease.
It has been suggested that there is less than a 1 in 10 chance of having
a child with some degree of keratoconus if one of the parents have keratoconus
without a family history. It occurs in all ethnic groups and is slightly
more common in females.
Keratoconus has been associated with other medical disorders including
atopic disease, Down's syndrome, Ehlers-Danlos syndrome, Marfan's syndrome,
craniofacial dysostosis, osteogenesis imperfecta and others. Even excessive
eye rubbing has been implicated in this disease.
Treatment of keratoconus depends on the severity of the condition. Initially,
eyeglasses are often successful in correcting the myopia and astigmatism.
As the disease advances rigid gas permeable (RGP) contact lenses are used
to correct the blurred vision of keratoconus by helping to neutralize
the astigmatism of the cornea. An alternative for people for whom rigid
lenses are not comfortable is a "piggyback" arrangement with
a soft lens next to the cornea and an RGP lens on top of that. Good lens
fit is essential for people with keratoconus, since a poor fit could aggravate
In about 10 percent of people, the cornea becomes too steep, or scarred,
and contacts can no longer be tolerated or cannot provide the necessary
vision correction. In these cases a corneal transplant is performed and
has approximately 90% success rate.
For more information or to subscribe to their news letter visit the
National Keratoconus Foundation web site.