Dec. 12, 2005 -- Implants of human retina cells may help soothe shaking and improve movement in people with advanced Parkinson's disease.
A new study shows the implants improved motor symptoms, such as muscle rigidity and tremors, by 48% one year after treatment, and those improvements were sustained for at least another year.
Parkinson's disease is a neurological disorder that causes uncontrollable tremors and difficulty starting and continuing movements. Most people with the disease require treatment with the drug levodopa to control symptoms. Patients with Parkinson's have a deficiency of the chemical dopamine. Levodopa converts to dopamine in the brain.
But long-term treatment with the drug, coupled with the progression of the disease, can lead to other motor problems, such as distorted movement.
Cells from the human retina called retinal pigment epithelial (RPE) cells produce levodopa naturally and can be taken from cadavers and grown in cultures.
New Avenue in Parkinson's Disease Treatment?
In the study, published in the Archives of Neurology, researchers examined the effects of implanting these retina cells attached to tiny microcarriers into the brains of six people with advanced Parkinson's disease.
The results showed the implants improved motor symptoms by an average of 48% up to two years after implantation. Improvements in activities of daily living, quality of life, and movement fluctuations were found without any the distorted movements typically associated with levodopa therapy.
Based on this small study, researchers say an additional study comparing the retina cell implant treatment with a placebo in people with Parkinson's disease has been started and will continue to look at the effectiveness and safety of the experimental treatment.