Usher’s Syndrome/ Retinitis Pigmentosa
Description of condition:
Usher syndrome is an inherited condition characterized by hearing impairment and progressive vision loss. The vision loss is due to retinitis pigmentosa (RP), a degenerative condition of the retina, and usually appears during adolescence or early adulthood.
There are at least three different forms of Usher syndrome. People with Usher syndrome type 1 (USH1) are born completely deaf and experience problems with balance. The first signs of RP — night blindness and loss of peripheral vision — usually appear in early adolescence.
In Usher syndrome type 2 (USH2), newborns have moderate to severe hearing impairment. Symptoms of RP typically start shortly after adolescence. Visual problems progress less rapidly than in Usher type 1 and hearing loss usually remains stable.
A rarer third type of Usher syndrome (USH3) was documented in 1995. Children with USH3 are usually born with good or only mild impairment of hearing. Their hearing and vision loss is progressive, starting around puberty. Balance may be affected.
Parts of the visual system affected:
Vision loss is due to a genetic mutation (alteration) affecting photoreceptor cells in the retina. The retina is a delicate tissue in the back of the eye composed of light-sensing photoreceptor cells. These cells — also known as rods and cones — are responsible for converting light into electrical impulses that transfer messages to the brain.
Effects on the condition of the visual system:
As Retinitis Pigmentosa develops, the retina slowly begins to degenerate, which will then affect the vision.
Symptoms:
Symptoms vary from person to person and progress at different rates.Balance may also be affected. RP( Retinitis Pigmentosa) begins with night blindness and gradual loss of peripheral vision.Glare is a significant complaint possibly due to the retinal disruption and light not being let in.
Common Treatments, including medications:
Presently there is no satisfactory treatment. It is important to understand that visual fields cannot be replaced. The best treatment depends on early identification to begin educational programs. The exact nature of these educational programs depend on the severity of the hearing and vision impairments as well as the age and abilities of the individual. Typically, orientation and mobility training; and communication services and independent living training that may include Braille instruction, low vision services, or auditory training.
Congenital, Adventitious, Progressive or Stable:
Congenital and Progressive Vision Loss
Anticipated Functional implications of the condition:
Regular-print materials are generally better than are large-print materials. Limit traveling in crowds or unfamiliar areas, difficulty arises because persons, objects, or obstacles in the periphery of vision (on the sides, above, or below) are not seen. Students may need to be seated farther away from visual targets to increase visual fields. A bioptic reversed telescope. Sector prisms mounted on the glasses.
References:
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3. _syndrome/article.htm
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5.Ophthalmo-logy Made Ridiculously Simple, Stephen Goldberg, MD, 2001 Miani: FL pg 40.
6.Program in Low Vision Therapy, Region 4 EducationServiceCenter, 2004, Houston, TX, pg. 23
7.When You Have a Visually Impaired Student in Your Classroom: A Guide for Teacher, Suzan J. Spungin, 2002, New York, New York, pg. 77-78