Retinitis Pigmentosa is the name given to a group of degenerative retinal diseases characterised by the breakdown of the retina. It
first leads to reduced night vision, then reduced peripheral vision and eventually total functional blindness. Loss of vision is generally reasonably symmetric and slow in progression.
Symptoms may include bumping into furniture, doorframes etc., difficulty seeing in low-light conditions and difficulty playing games
(tennis, soccer etc.), and, upon examination with a light, small dots on the retina.
It can be transmitted by an autosomal recessive gene, an autosomal dominant gene or can be sex-linked, although occasionally it can be the result of a mutation in a gene.
It is thought that about every 1 in 4000 people have it, i.e. 1.5 million people around the world, and it is the leading cause of blindness
in the west for people under 60, but despite the numbers, there is no known way to slow the disease and the only way to regain sight is by
Retinitis Pigmentosa is a contraindication of Sildenafil, an erectile dysfunction drug also known as Viagra.
Related diseases are Usher Syndrome, Choroideremia and Refsum Syndrome.