>I'm back to seeing things in Black and White again.
>No color all last evening nor today, but this evening
>the color is coming back.
>I had this problem after my colon ruptured and I was under
> so long during surgery. I didn't see any colors for
>several months after that surgery.
> But I haven't had surgery and
>I haven't been sick. Well, if you can call having PD NOT being
>sick.
>
>
Marjorie, this might be the answer.
Price MJ, Feldman RG, Adelberg D, Kayne H
Department of Ophthalmology, School of Public Health, Boston University School of Medicine, MA.
Dopamine is a neurotransmitter found in the retina. Delays in the visual evoked responses and abnormalities in contrast sensitivity occur in patients with Parkinson's disease. Improvement in the P100 has followed L-dopa therapy. Suspected abnormalities at the retinal level in Parkinson's disease are observed in reductions in photopic, scotopic, and pattern-derived electroretinograms. We studied 35 patients with Parkinson's disease and 26 controls of comparable age and visual acuities using visual evoked responses, color vision, and contrast sensitivity testing. Contrast sensitivity thresholds were significantly different at most frequencies tested, using both stationary and temporally modulated sinusoidal gratings. The total error score of the Farnsworth-Munsell 100 Hue Test revealed significant differences between the patients and controls. The contrast thresholds derived from certain spatial frequencies and the total error in color score were significantly related to the duratio
n of disease. A stepwise discriminant analysis correctly identified 94% of the patients and 94% of the controls. The significant error in chromatic discrimination observed in Parkinson's disease patients may be due to altered intraretinal dopaminergic synaptic activity in these patients.
PMID: 1565248, UI: 92228188
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John Cottingham
