Before they were diagnosed, Betti Lidsky's children had the telltale signs of night blindness and tunnel vision.
One of her daughters was in theater school and started falling off the stage because of tunnel vision. She also often crashed into things when walking.
"Some people with RP still have 20/20 vision but are virtually blind. They can read the eye chart, but their field of vision is so narrow can't find their way out of the room," said Berson.
Berson says RP is treatable. He was one of the authors of a study sponsored by the National Eye Institute that found it could slow the disease with vitamin A palmitate, given in a certain dose as part of a regimen that includes eating oily fish.
He stressed there's often confusion about vitamin A palmitate.
"It's not pure vitamin A, and it's not beta-carotene. Beta-carotene is not a suitable substitute for vitamin A palmitate, and pure vitamin A can be toxic in very high doses."
But Bhavsar says that study had some safety issues and the findings were never proven. As far as other potential treatments are concerned, there really isn't anything that works particularly well.
"There are some treatments that suggest some benefits, but at the present time, it would be most accurate to say there is no standard proven accepted treatment," he said.
Researchers are looking into other avenues, including gene therapy and implanting a growth factor that can slow retinal degeneration.
The discovery of the Lidsky family gene gives experts hope, but they know that a potential cure is way off.
Lidsky now has 11 grandchildren, and she and her affected children worry about how many of the next generation will have RP. Now that the family gene has been isolated, getting an answer will be much easier.
"Now, we can test them all with a simple blood test," she said.