What is Retinitis Pigmentosa – Causes and Symptoms
Retinitis Pigmentosa is a progressive eye disease, affecting the retina. People suffering from this disease retain their vision up to the age of 40 or 50 years. It is rare as only one person for every 4000 individuals develops this disease in the United States. It is one of the most common forms of inherited eye diseases involving the damage of the retina. This article tries to understand the causes and symptoms of this disease.
Causes of Retinitis Pigmentosa:
- Cells are the building blocks of life. collection of cells form tissues, which in turn unite to form an organ of the body.
- Normal functioning of cells is regulated by chemical instructions called genes.
- There are many factors which change the chemical structure of these genes. This process is technically called mutation.
- This disease is caused by mutation in more than 100 genes associated with the normal functioning of the eye.
- In 1989, mutation in a gene for a pigment called rhodopsin associated with low-light conditions, was first identified.
- 100 mutations were found in later studies carried out on this gene making it responsible for 15 percent of all types of degeneration in retina.
- Mutation of a chemical called codon 23 associated with rhodopsin causes largest fraction of mutations in this gene in the United States.
- Up to 150 mutations have been found since 1990 in another gene called opsin associated with this disease.
- A rare kind of mutation in codon 23 was found in the year 2000 leading to autosomal dominant form of retinitis pigmentosa.
Symptoms of Retinitis Pigmentosa: Though the symptoms appear in the childhood, severe vision problems become apparent only in adulthood. Some of the signs to look out for are:
- Progressive retinal degeneration
- Peripheral vision loss
- Progressive vision loss
- Tunnel vision
- Loss of side (peripheral) vision
- Decreased vision at night or in low light
- Retinal pigment epithelium mottling
- Loss of central vision (in advanced cases)