Retinitis pigmentosa is an eye disease in which there is damage to the retina. The retina is the layer of tissue at the back of the inner eye that converts light images to nerve signals and sends them to the brain.
Retinitis pigmentosa can run in families. The disorder can be caused by a number of genetic defects.
The cells controlling night vision (rods) are most likely to be affected. However, in some cases, retinal cone cells are damaged the most. The main sign of the disease is the presence of dark deposits in the retina.
Symptoms often first appear in childhood, but severe vision problems do not usually develop until early adulthood.
The main risk factor is a family history of retinitis pigmentosa. It is an uncommon condition affecting about 1 in 4,000 people in the United States.
- Scientists at the RIKEN Center for Developmental Biology in Japan have created a retina from mouse embryonic stem cells that could pave the way for treatments for human eye diseases, including some forms of blindness. Created by coaxing the stem cells into a precise three-dimensional assembly, the “retina in a dish” is by far the most complex biological tissue engineered yet, scientists say. If the technique can be adapted to human cells and proved safe for transplantation it could offer an unlimited well of tissue to replace damaged retinas. More immediately, the synthetic retinal tissue could help scientists in the study of eye disease and in identifying therapies. The work may also guide the assembly of other organs and tissues. (Nature, April 6, 2011)