Usher syndrome is the medical term used to describe a partial or total hearing loss from birth and a gradual vision loss from retinitis pigmentosa. Some people with Usher syndrome also have balance problems.
A person with the syndrome is usually someone who has known they are deaf or hard of hearing from early life. Later in life, they find out that they have retinitis pigmentosa when their eyesight starts to change and they have trouble with night blindness and ‘tunnel vision’.
Some people’s vision starts to change when they are children, other people’s vision doesn’t change until much later. The syndrome affects people differently.
The combination of retinitis pigmentosa and hearing loss interact in a complex way that affects communication and mobility.
A person with the syndrome is born with it, which means it has genetic component.
There are three main types of Usher syndrome – Type 1, 2 and 3. For these three types, some dozen or so responsible genes have been identified and research continues in this area.
Usher syndrome Type 1
This is the most common form of the syndrome.
There is profound congenital deafness. Retinitis pigmentosa is usually apparent within the first 10 years of life. The level of vision loss varies over time.
There are balance problems, but these don’t get worse with age, however they may seem worse as the field of vision reduces. People with Type 1 tend to use signing as their mode of communication.
Usher syndrome Type 2
This is the second most common type. Hearing loss ranges from mild to severe. Retinitis pigmentosa is apparent from late adolescence to late twenties. There are no balance problems.
The level of hearing and vision loss can vary in within family members. The hearing loss is usually not progressive, but is affected by the aging process.
Usher syndrome Type 3
This is extremely rare and not much information is available. People with Type 3 are born hearing and sighted. They usually begin to lose their hearing and vision in their 30’s and the loss is often rapid.
Retinitis pigmentosa
Retinitis pigmentosa is the name given to a genetic eye condition that causes degeneration of the retina. The retina is the light-sensitive tissue inside the eye where the first stages of ‘seeing’ take place. The retina slowly degenerates and loses its ability to transmit pictures to the brain, and in advanced stages clumps of pigment appear in the retina, hence the term retinitis pigmentosa.
The first symptom of retinitis pigmentosa is often night blindness and an inability to see in poor lighting conditions. A narrowing of side vision, which is called tunnel vision also occurs.
In some cases retinitis pigmentosa leads to serious vision impairment. Most people retain some useful vision for many years.