Usher Syndrome
What is Usher syndrome?
Usher syndrome is the most common condition that affects
both hearing and vision. A syndrome is a disease or disorder that has more than
one feature or symptom. The major symptoms of Usher syndrome are
hearing loss and an eye
disorder called retinitis pigmentosa, or RP. RP causes night-blindness and a
loss of peripheral vision
(side vision) through the progressive degeneration of
the retina. The retina is a light-sensitive tissue at the back of the eye and is
crucial for vision. As RP progresses, the field of vision narrows - a condition
known as "tunnel vision" - until only central vision (the ability to see straight
ahead) remains. Many people with Usher syndrome also have severe balance
problems.
There are three clinical types of Usher syndrome:
- type 1,
- type 2, and
- type 3.
In the United States, types 1 and 2 are the most common types. Together, they
account for approximately 90 to 95 percent of all cases of children who have
Usher syndrome.
Photograph of the retina of a patient with Usher syndrome (left) compared to
a normal retina (right). The optic nerve (arrow) looks very pale, the vessels (stars)
are very thin and there is characteristic pigment, called bone spicules (double arrows).
Next: Who is affected by Usher syndrome? »
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