Unfortunately, there is no cure for Retinitis pigmentosa as of now. As already pointed out, low vision
aids will help you for near work. Other than this, i can point out the conclusions of some studies conducted regarding RP and oral supplements (Consult your ophthalmologist for more details):
1)
Vitamin A supplementation has been found, in some studies to slow progression of the disease. But no clear guidelines exist on supplementation.
2)Omega 3 fatty acids and lutein/zeaxanthain, bilberry extract, vitamin c supplements are also helpful
3) Oral Acetazolamide is helpful in cases of RP with macular edema
4) Normal dietary vitamin E is fine but taking High dose Vitamin E supplements are detrimental to the disease and have been found to cause faster progression
5)Oral valproic acid has also been found useful in small studies and is undergoing larger trials
6) Viagra (sildenafil) and Isotretinoin (used for treating acne) are better avoided in RP patients
I hope this is helpful. Until the Argus II implant (bionic eye) comes into the mainstream market, you will have to manage with these limited choices.