Vision Diseases, Disorders & Definitions
# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
What Is Usher Syndrome? Usher syndrome is an inherited condition that causes
- 1.A serious hearing loss that is usually present at birth or shortly thereafter
- 2.Progressive vision loss caused by retinitis pigmentosa (RP)
RP is a group of inherited diseases that cause night-blindness and peripheral (side) vision loss through the progressive degeneration of the retina, the light-sensitive tissue at the back of the eye that is crucial for vision.
Researchers have described three types of Usher syndrome-type I, type II and type III.
- Individuals with Usher syndrome type I are nearly or completely deaf and experience problems with balance from a young age. They usually begin to exhibit signs of RP in early adolescence.
- Individuals with Usher syndrome type II experience moderate to severe hearing impairment, have normal balance, and experience symptoms of RP later in adolescence.
- Individuals with Usher syndrome type III are born with normal hearing but develop RP and then progressive hearing loss.
Portions of this page are excerpted from Dictionary of Eye Terminology, copyright 1990-2006 by Barbara Cassin and Triad Communications. Reprinted with permission.
Some of the information above is reprinted from the National Eye Institute, National Institutes of Health, and is for educational purposes only. Superior Vision strongly recommends eye exams as the best way to diagnose eye conditions and learn more about potential vision problems.