Retinitis Pigmentosa (RP) is a group of inherited diseases that causes degeneration of the retina.
It is the most common form of inherited blindness that affects approximately 1 out of every 3,700 people.
Currently,it is estimated that 100,000 people in United States are diagnosed with this condition.
The retina is a light-sensitive layer of tissue located at the back of the eyeball.
It’s primarily purpose is to convert light rays into nerve impulse signals, which is sent to the brain where they are recognized with images.
RP causes progressive loss of the light-sensing cells in the retina which can begin as early as age of 10.
It usually starts with deterioration of the rod cells that are responsible for peripheral and dim light vision.
That is why, the first symptoms of RP are often increasing night blindness which causes great difficulty in seeing at night, and loss of peripheral vision.
The gradual loss of peripheral vision will make you feel as if you are viewing at the world through a tunnel.
The rate of progression and degree of visual loss varies from person to person.
Majority are considered legally blind when they reach 40, with a central visual field of less than 20 degrees in diameter.
The symptoms will depend on which type of light-sensing cells (rods or cones) are being affected.
If rods are involved:
If cones are involved:
RP are mostly inherited.
If you or your partner has RP (even if there are no symptoms), there is a 25 to 50% chance that it is going to be passed down to your child.
Therefore, if you are planning to have children, discussing the inheritance pattern with a genetic specialist may be helpful.
RP is caused by genetic mutations inherited from one or both parents.
In order to function properly, the light-sensitive cells (rods and cones) requires a certain amount of specific proteins.
However, mutated genes provide the wrong instructions to the cells, asking them to either make too much or too little protein.
This causes the cells to become dysfunctional and eventually deteriorate.
Unfortunately, there isn’t any sure safe and effective cure available for RP yet.
Supplementation of vitamin A and zinc may help to slow the progression of RP.
Researches show that vitamin A is an important nutrient needed in the retina for the rods and cones to function properly. And zinc helps to transport vitamin A. (Personally, I recommend taking eye vitamins to supplement your eye health.)
However, both are toxic in high level and may damage your liver. Check with you eye doctor on the appropriate dosage if you are interesting in using this approach.
There are also studies claiming that Omega-3 essential fatty acids can further slow the disease progression.
This is not surprising as Omega-3 fatty acids are known to be a great ally for the eyes.
To increase your Omega-3 intake, add more cold-water fishes such as salmon or tuna to your diet.
If you don’t like fishes or afraid of mercury poisoning, eat plenty of nuts and seeds. Both are rich in these essential fatty acids.
Currently, there are new researches in exploring gene therapy, that is inserting healthy genes into the retina so that the light-sensitive cells can be re-instructed to prevent degeneration.
Even though, this is still in the testing stage (mouse models), there are positive results of the experiments.
Hopefully in the near future, we have a real cure for retinitis pigmentosa.
Lastly, if you have RP, learning how to adapt to the vision loss is important.
It is highly recommend that you get in touch with a low-vision specialist as they can give advises and recommend visual aids that can help you to live an independent life.
Wearing sunglasses may also help to preserve vision by protecting the retina from ultraviolet rays.