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Keratoconus: What is it?
Symptoms You May Experience:
Examination: What Your Eye Doctor Will Look For:
What You Can Do:
When To Call Your M.D.:
Treatment:
Prognosis: Will I See Better?
The cornea
is the clear, dome-shaped surface that covers the front central area of
the eyeball and focuses light on the retina. In keratoconus the
cornea is abnormally shaped because its middle area is thin and bulges
out, resulting in a cone shape rather than a smoothly curved
cornea. Mild cases may cause distorted vision because of the
cornea's shape. In moderate or severe keratoconus, the thinned
cornea can develop tiny cracks that lead to corneal swelling and eye
pain (acute hydrops). Scarring of the cornea can also occur.
In the United States keratoconus occurs in about 1 of every 2,000 people, most of whom are diagnosed in their teens or early twenties. The shape of the cornea in keratoconus tends to stabilize after young adulthood. When present, keratoconus is almost always found in both eyes, but one eye may be worse than the other. The cause of the disease is not known, but keratoconus can run in families and has been linked to frequent eye rubbing, long term use of contact lenses, Down syndrome, and other rare diseases.
In the United States keratoconus occurs in about 1 of every 2,000 people, most of whom are diagnosed in their teens or early twenties. The shape of the cornea in keratoconus tends to stabilize after young adulthood. When present, keratoconus is almost always found in both eyes, but one eye may be worse than the other. The cause of the disease is not known, but keratoconus can run in families and has been linked to frequent eye rubbing, long term use of contact lenses, Down syndrome, and other rare diseases.
You may
have trouble seeing clearly even with a new eyeglass prescription, and
your prescription may change significantly between regular eye
exams. If you wear contact lenses, the lenses may easily fall out
of your eyes.
The eye
doctor will examine the shape of your cornea with a slit lamp and look
for thin or steep areas. Specialized photographs of the cornea
called corneal topography may be taken to measure the cornea's
steepness and shape.
Reduce the
number of hours you wear contact lenses and avoid rubbing your eyes
excessively. Keeping up with regular eye exams can help your eye
doctor notice if your glasses prescription changes rapidly.
If you
notice decreased vision despite a new eyeglass prescription, you should
call your eye doctor. If you have keratoconus and experience eye
pain, excessive tearing, or decreased vision, call your eye doctor,
since these symptoms could mean that your cornea has thinned to a
certain point and needs treatment.
In mild
keratoconus, properly prescribed eye glasses or, more commonly, hard
contact lenses usually improve vision by compensating for the steepness
of the cornea. Episodes of acute hydrops may be treated with eye
drops or a soft contact lense. In moderate or severe keratoconus,
a corneal transplant may ultimately be needed.
Most
keratoconus patients do extremely well with hard contact lenses.
If corneal transplantation is necessary, these patients tend to heal
well, and many experience good vision afterward.
Above: Example Of Keratoconus (Click For Bigger View-Warning:Graphic)
