Retinitis Pigmentosa is a diverse group of genetic eye disorders in which the retina degenerates slowly and progressively, eventually resulting in blindness and diminished peripheral vision.
Retinitis Pigmentosa Symptoms
- Early Symptoms: Retinitis Pigmentosa sets in gradually. In the majority of the patients, the early symptoms start to appear between childhood and the age of 30. At first, the patients find trouble adjusting to a dimly light room or have difficulty with night vision. Then, there is a loss of peripheral vision or peripheral visual field. This leads to tunnel vision. On exposure to bright light or sunlight, people with retinitis pigmentosa experience glare.
- Later Symptoms: It is a progressive disease, but the pattern and speed of vision deterioration vary from one patient to another. Seeing detailed images becomes a hassle in the later stages of the disease. Central vision may become compromised in the latter stages of the disease.
Retinitis Pigmentosa Causes
- Inheritance: It is a hereditary disorder and the majority of people get it from their parents. The photo-receptor cells present in the retina need protein to function normally. Any harmful changes in the genes that carry instructions for making proteins affect largely. It may lead to the production of toxic, abnormal protein or may fail to make the required protein. In the absence of the protein or due to damaged protein, the photo-receptor cells stop working and start to die. It inevitably results in retinitis pigmentosa.
- Genetic Mutations: Some cases of retinitis pigmentosa are linked to genetic mutations on the X chromosome.
- Dominant Gene: Sometimes, a dominant gene causes this eye condition. A few people develop the disorder if they inherit the mutated gene from any of the parents.
- Random occurrence: In rare cases, people with no family history of retinitis pigmentosa have this eye disease. It occurs when one parent carries the altered gene, or the genetic mutation occurs during the development of the sperm, egg or embryo randomly.
It is important to understand that patients with retinitis pigmentosa may have involvement of other organ systems, especially hearing, and a detailed work-up is important.
Retinitis Pigmentosa Treatment
Extensive research has been carried out to find a cure for retinitis pigmentosa. However, there is no effective treatment available at the moment. There are some ways to manage the condition, which include:
- Vision Aids: When patients with retinitis pigmentosa are exposed to sunlight or bright light, they experience glare. So, to help improve their tolerance of sunlight or bright light, a light amber filter is added to general eyeglasses. To help the patients, the ophthalmologist may offer vision aids such as magnifiers, lamps, and video screens.
- Vitamin A: During some retinitis pigmentosa treatment research, it is found that high doses of Vitamin A may help to slow down the progression of this condition. Significant benefit is not noted and it is beneficial only when started in the early teenage year. More research in this field is required to determine its effectiveness as high doses can lead to Vitamin A toxicity.
- Topical Treatment : Topical therapy with carbonic anhydrase inhibitors have shown to diminish the macular edema associated with retinitis pigmentosa. However, the edema tends to return whenever the therapy is discontinued.
- Gene Therapy: Currently, gene therapy is being studied worldwide as a possible treatment. It is experimental and involves replacing the damaged gene or deactivating mutated genes that are causing retinitis pigmentosa. Some research is carried out in techniques that involve inserting a new gene.
- Retinitis Pigmentosa Surgery: Clinical trials are carried out for implantable devices like artificial retina and that are looking promising at the current stage. Studies involving gene mapping are done internationally.
Most of the retinitis pigmentosa treatment work has so far been only done in the laboratory, but extensive research may be able to offer promising results in the future.