Many people have not heard of retinitis pigmentosa, but will recognise some of the following terms.
This term reflects one of the symptoms of RP. As the rod cells (the cells that enable you to see in dim light) of the retina fail, someone with RP cannot see in the dark. For example, a dimly lit room becomes one of total blackness. Sometimes, this manifests itself in a child being afraid of the dark. Transferring between different levels of light in different rooms or spaces can be very difficult for someone with RP.
Typically, sight loss is initially peripheral and progresses to tunnel vision, which becomes narrower and narrower just as the term implies.
A general terms to describe conditions that result in the degeneration of retinal cells, including the various forms of RP. For many, the terms mean the same thing.
Rod-Cone and Cone-Rod Dystrophy
Terms used to describe forms of retinal degeneration in which the rod cells deteriorate before the cone cells, and vice versa. Rod cells are by far the more numerous of the light-sensitive cells in the retina and allow you to see in dim light and provide peripheral vision. Cone cells are found centrally and provide detailed central vision and colour perception. The pattern of sight loss will vary depending on the rate at which different cells in different areas of the retina are affected.
Specific types of RP
Some types of RP caused by specific genes and with particular patterns and rates of sight loss are named. You may hear terms such as Leber’s Congenital Amaurosis, Choroideremia, Stargardt’s Disease, and others. If you are unsure whether the terminology your consultant has used means you have a form of RP, you should ask for this to be clarified.
Some gene faults that cause RP also cause other disabilities or medical conditions. These are known as RP Syndromes and include Usher’s Syndrome, Bardt Beidl Syndrome, and others. These are described in more detail in the RP and Other Disabilities section of this pathway