Learn about research focusing on the cause, prevention, treatment, and cure of retinal disease in this medical report.
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Host: On a recent trip to Los Angeles, we caught up with Dr. Gerry Chader, who is the Chief Scientist of the Doheny Retina Institute at University of Southern California School of Medicine. Dr. Chader’s research focuses on the cause, prevention, and treatment, as also cure of retina disease. Question: What is retinitis pigmentosa? Dr. Gerry Chader: Retinitis pigmentosa is really a family of diseases. It’s a catch phrase for grouping. Right now, there are well over 100 gene mutations that are known to ultimately result in one form or another of retinitis pigmentosa. What is noticed is that very often since it strikes early in life, either at birth or soon thereafter, a parent will notice that a child is clumsy, at dawn or dusk or under low light conditions, he is bumping into furniture, he is having a little trouble managing mobility and this part of either slow or clumsy or something like that and in fact they are not and in fact these are the early signs of retinitis pigmentosa. The two hallmarks of RP are that there is a loss of peripheral vision, again they don’t see a baseball coming at their head as such from somewhere out in the field as such. Secondly that because the rod photoreceptor cells are the main cells affected and are in the periphery unless peripheral vision is lost then first, but also rod photoreceptor cells some sort of dim vision as such. Bright light vision, day light vision as such mainly observed by the cone photoreceptor cells. So with rods going wide, genetic mutations mainly affecting the functioning of the rod cells. Then the peripheral vision and the dim light vision are the first to go. So at age three or four, a parent is saying, Johny now get up out of that bed and get into the bathroom and brush your teeth or something and Johny fumbles and goes into the door jam such. So it’s silent. There is no pain. It comes unusually quite slowly. So a parent will often take the child into a pediatrician rather than ophthalmologist, not understanding that really this is an Acular condition and hopefully then the pediatrician realized in fact what’s going on, there is an eye exam. That really can’t be an eye exam just for a cutie because very often you need cutie in -- patient is very good. I know people with very response to retinitis pigmentosa who have what is called their adults – and they have what’s called short gun or tunnel vision, only a few degrees, five or eight degrees of vision and so it’s like looking down the barrel of a long shot gun. But they can’t define as such because their visuals acute is just fine in the macular, it’s the cone that’s going to put. They can’t drive, anything coming at them, out of their peripheral vision is not seen at all but they sure with scanning can do pretty well in reading and face recognition and other things like that. The other more obvious problem in retinitis pigmentosa is presented in congenital forms of our P. There is a form of our P called Leber’s congenital amaurosis and basically the child is born blind. Has wandering eye, the eyes wander back and forth as such and so this is a lot easier to spot because the child is not focusing on the parent’s face, the eyes are wandering back and forth after a few months after birth. So pretty quickly these children are taken into the ophthalmologist. Question: If I had retinitis pigmentosa? Dr. Gerry Chader: There is one treatment right now. That is thanks to the good research at Harvard -- in Boston, Massachusetts. Back in the 90s, Ely have found that many of his patients were higher regimens of vitamins and some of these seem to do a bit better. So he chose two vitamins, vitamin A and Vitamin E to do an in-depth study of and found that in some patients on vitamin A, very high vitamin A measurement, that the vision was improved. But only some patients and the vision was only slightly improved such that vision in those patients continued to decline but at a slower pace. So his estimate was 8-10 years or so of