What Is Keratoconus?
Author: Heather Colman

Keratoconus 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 conical shape than its normal, even
curve. Keratoconus can cause substantial distortion of the
vision, with multiple images, streaking and sensitivity to
light all often reported by the patient. Though frequently
thought of as a rare condition, keratoconus is the most common
dystrophy of the cornea, affecting around one person in a
thousand, and it seems to occur equally in all ethnic groups
worldwide. 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 the course of its progression following diagnosis is
unpredictable. Deterioration in vision associated with the
disease, if in both eyes, can affect the person's ability to
drive a car. It does not, however, lead to blindness, and in
most cases, corrective lenses are effective enough to allow the
patient to continue to drive legally and likewise function
normally. Further progression of the disease may lead to a need
for surgery. Keratoconus continues to be a somewhat mysterious
disease, but it can be successfully managed with a variety of
clinical and surgical techniques often with little or no
impairment to the patient's quality of life.

Symptoms
A simulation of the multiple images seen by a person with
keratoconus. People with early keratoconus typically notice a
minor blurring of their vision and come to their clinician
seeking corrective lenses for reading or driving. At early
stages, the symptoms of keratoconus may be no different from
those of any other refractive defect of the eye. As the disease
progresses, vision deteriorates, sometimes rapidly. Visual
acuity becomes impaired at all distances, and night vision is
often quite poor. Some individuals have vision in one eye that
is markedly worse than that in the other eye. Some develop a
sensitivity to bright lights, eye strain from squinting in
order to read, or itching in the eye. Otherwise, there is
little or no sensation of pain.

The classic symptom of keratoconus is the perception of
multiple 'ghost' images, known as monocular polyopia. This
effect is most clearly seen with a high contrast field, such as
a point of light on a dark background. Instead of seeing just
one point, a person with keratoconus sees many images of the
point, spread out in a chaotic pattern. This pattern does not
typically change from day to day, but over time it often takes
on new forms. Patients also commonly notice streaking and
flaring distortion around light sources. Some even notice the
images moving relative to one another in time with their heart
beat.

Cause
Despite considerable research, the cause of keratoconus remains
somewhat of a mystery. According to the United States National
Keratoconus Foundation it is likely that keratoconus can arise
from a number of different factors: genetic, environmental or
cellular, any of which may form the trigger for the onset of
the disease.

Treatment
In early stages of keratoconus, spectacles can suffice to
correct for the mild astigmatism. As the condition progresses,
spectacles may fail to provide the patient with a satisfactory
degree of visual acuity, and most clinical practitioners will
move to managing the condition with contact lenses.

In keratoconic patients, contact lenses improve vision by means
of tear fluid filling the gap between the irregular corneal
surface and the smooth regular inner surface of the lens,
thereby creating the effect of a smoother cornea. Many
specialized types of contact lenses have been developed for
keratoconus, and affected people may seek out both doctors
specialized in conditions of the cornea, and contact-lens
fitters who have experience managing patients with keratoconus.


Disclaimer
The information presented here should not be interpreted as
medical advice. If you need more information about Keratoconus,
please consult a qualified physician or eye specialist.

Permission is granted to reprint this article as long as no
changes are made, and the entire resource box is included.


About The Author: This article is Copyright © 2006, Heather
Colman. Find more keratoconus resources at:
http://www.keratoconus-hub.info