Suggested assessment routines
At the schools for the deaf, RP students' vision should be assessed at the beginning of each school year so teachers are aware of possible new limitations. To improve communication related to retinal disorders, typical changes in vision caused by retinitis pigmentosa can be covered as a part of biology lessons. This increases understanding among the other deaf students of vision problems and lessen the now common negative attitudes among the deaf toward visually impaired deaf people.
Also RP students with normal hearing or some hearing loss in mainstream education need to have their vision and hearing tested at the beginning of each school year.
Changes in visual acuity and contrast sensitivity are usually small and do not cause problems in seeing study materials or the black board. Spectacles are regularly checked, therefore children need to learn how to respond when the lens power is subjectively tested. The use of magnifying devices is often limited to simple magnifiers. In rare cases vision loss may be so severe that a high school student needs to use a TV-reading aid (CCTV) and a computer to have high enough contrast in the reversal picture. The devices are not used for magnification but to enhance contrast. Changes in visual acuity and contrast sensitivity can be measured at school and compared with values reported by the ophthalmologist and low vision therapists.
The range of visual adaptation may change at any grade level and become so narrow that it causes problems both at high and low luminance levels. Loss of twilight vision means difficulties in mobility and thus mobility instruction should be started, first concentrating on orientation landmarks on the way to and from school, and to and from evening activities. Visual adaptation to darkness may not be measured at the low vision clinic, so it needs to be assessed at school, both by using the Cone Adaptation test and by observing the speed of adaptation when the child enters poorly lit areas.
Visual fields are routinely measured at the eye clinic. Nowadays automated perimetry is often used instead of Goldmann fields. This may cause sad misunderstandings because this test may incorrectly indicate that there is a deep ring scotoma, when there is no functional ring scotoma but only a relative loss of sensitivity. It has happened that a child has been given advice not to ride the bike any more "because of the tubular field" when the child's visual field is still 180 degrees. Always assess the size of the visual field in day light and in twilight and discuss with the child whether objects disappear in the area of the ring scotoma or not.
Nearly every child with chronic illness or impairment goes through a more or less clearly expressed depression around the age of nine years (Lagerheim 1983, see References), or sometimes a few years earlier or later. This happens when it dawns on the child that parents and medical experts are unable to make them like their peers and that they have to include their impairment and disability as a special feature into their self image. Since the depressive period is so common, it should be remembered during the vision assessment and it should be known at the school. Information about the impairment should be given with an accepting tone, stressing the fact that the child is healthy with a functional problem. The school and the low vision services should work together to help the child through this difficult time.
Contact with other children having similar or more severe problems helps the child get a realistic picture of his/her situation and often gives the parents much needed emotional support. These contacts can for example be accomplished at weekend gatherings and during holiday camps. Young, well-adapted Usher adults are important role models for Usher children. Their visits to schools are often experienced positively by both the Usher children and their peers.