Usher Syndrome
What is Usher Syndrome?
Usher Syndrome is a genetic condition which causes hearing loss
from birth, and a later progressive loss of vision due to Retinitis
Pigmentosa (RP). The condition was named after CH Usher, a British
opthamologist. There are three types of Usher Syndrome - I, II and
III.
Symptoms
Each type presents slightly differently - hearing problems will
vary and some people will also experience difficulties with
balance. In all cases sight deteriorates as a result of RP. This is
the name given to a group of hereditary eye disorders. They damage
the retina, the light sensitive tissue lining the back of the eye,
in which the first stages of seeing take place. . As a result, deaf
people in their teens and twenties may seem clumsy and, for
instance, bump into lamp posts or fall down steps.
The first sign of RP is usually night blindness or temporary
blindness when going from a dark to a bright place, for example
moving outdoors. As RP progresses, the field of vision narrows
until only the central vision remains - this is known as 'tunnel
vision.' The degree of sight loss and the rate of decline vary
depending on the individual. Most people with RP retain some
useful, central vision into old age.
Type 1
|
Type 2
|
Type 3
|
| Born with a profound hearing loss. |
Born with a moderate to severe hearing loss. |
Hearing loss that gets progressively worse over time. |
| Balance problems. |
Develop night-blindness in their twenties, due to Retinitis
Pigmentosa. |
Develop visual impairment around the age of 20-30 years due to
Retinitis Pigmentosa. |
| Develop night-blindness in their teens or earlier, due to
Retinitis Pigmentosa. |
No balance problems in childhood. |
May have balance problems later. |