Although many students with Usher syndrome may be unaware that they have a visual loss, they do realize, and often at an early age, that they have difficulties with vision that other kids don't seem to have.
A common first sign of Usher syndrome is the inability to see clearly at night. Parents or teachers may notice a number of things: that the child trips or bumps into objects; has problems walking around the home in dim light; is uncomfortable with unfamiliar steps or curbs; and may have a heightened fear of the dark.
A second sign is the inability to see peripherally (above, below, and to the sides) under any lighting conditions. This is often described as tunnel vision. A student with Usher syndrome may not notice another student waving hello from the side, an obstacle on the floor, a step or curb, a street pole off to the side of one shoulder, etc.
Another sign is difficulty adjusting to changes in lighting: entering or leaving a darkened movie theater; entering or leaving a building on a bright sunny day.
Additional signs are problems in maintaining balance, blind spots (scotoma), sensitivity to glare (under snow, bright light or sun conditions), and problems with clarity of central vision (acuity).
To summarize, the common signs of Usher syndrome are:
All students with Usher syndrome have hearing loss and retinitis pigmentosa (RP). In the typical course of RP, blood vessels constrict decreasing the flow of vital nutrients to the peripheral retina. The retina of the human eye contains two types of light-receptor cells, rods and cones. Cones allow us to see clearly under daylight conditions and give us our color vision. Rods allow us to see clearly under evening light conditions, and give vision only in shades of gray. The loss of night vision is caused by the deterioration of rods.
The peripheral part of the retina is where there the highest concentration of rods exists. As these cells die, the ability to see clearly in the evening decreases. This is what most students with Usher syndrome experience first, the loss of night vision, or what is commonly called night blindness.
At this time (June 1997) there is no cure for the degenerative eye disease known as retinitis pigmentosa. Research is moving rapidly and focuses on two main areas: genetic research and transplantation of retinal tissue.
from Ilene Miner, CSW & Joe Cioffi, M. Ed.: Usher Syndrome in the School Setting
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Original address of this page:
www.tr.wou.edu/dblink/usher-II.htm
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