People with Parkinson’s disease showed marked improvement after surgeons implanted in their brains chemical-producing cells taken from the eye of a dead donor, researchers said on Monday.Cells from the inner, or pigment, layer of the eye’s retina make levodopa, which Parkinson’s patients commonly take in pill form to replace lost production of the neurotransmitter dopamine.Dopamine allows the brain to control and smooth the body’s movements.For most patients, the levodopa pills lose their effectiveness over five years or less, and larger and larger doses are needed to keep at bay the involuntary movements and shaking symptomatic of the disease.Many people on the drug develop involuntary writhing or dance-like movements.The retina cells were cultivated and implanted in the brains of six patients with advanced Parkinson’s, researcher Natividad Stover of the University of Alabama said.One year later, the patients scored 48 percent higher on tests of movement and coordination, and the improvement was sustained after two years, Stover wrote in the journal Archives of Neurology.
