Retinitis pigmentosa patients doesn't have:-

Not all, but many studies have found that patients with retinitis pigmentosa tend to have lower blood levels of DHA (Docosa Hexaenoic Acid, o3, 22:6), an omega -3 fatty acid found in the photoreceptor cells. ADDITIONAL READING ON DHA: Also known as Cervonic acid. This is having 22 C and 6 double bonds (Docosa means 22, Hexaenoic means 6 double bonds). These days health drinks (bournvita, horlicks) are foified with DHA, as it is impoant for the brain and retina development in infants and children. Decreased amounts lead to increase risk of Retinitis Pigmentosa. DHA is present in high concentration in sperms, retina, cerebral coex. Constant source of DHA is breast milk. Synthesized to a limited extent from a-linolenic acid or obtained directly from fish oils.