L-dopa improves colour vision in Parkinson's disease

Abstract

In recent studies disorders of colour vision in Parkinsonian patients have been demonstrated. Up to now, the influence of dopaminergic treatment on those phenomena remains unclear. We therefore performed a colour vision test (Farnsworth-Munsell 100 Hue Test) in 19 patients with Parkinson's disease before and after the oral application of the morning dose of L-Dopa. The colour discrimination was significantly improved after the ingestion of L-Dopa. There was no different effect of L-Dopa on the blue-yellow or red-green axis of colour vision. The morphological structures responsible for these colour vision disturbances are unknown, but it can be concluded that the dopamine deficiency in Parkinson's disease is not restricted to the basal ganglia but may involve the visual system as well.

Chromatic pattern-reversal electroretinograms (ChPERGs) are spared in multiple system atrophy compared with Parkinson’s disease

“…By contrast, the same responses are not significantly different from controls in our particular group of MSA patients. PERG abnormalities in IPD have been related to dopaminergic deficiency [33][34][35][36], as they are found in cases of neuroleptic-induced Parkinsonism and can be corrected by l-dopa administration [1,37]. A retinal dopaminergic component for visual dysfunction in IPD has been proposed by several authors [3,8,34,38].…”

Methoden zur Frühdiagnose des Morbus Parkinson

“…Neben Störungen des Kontrastsehens wurden Auffälligkei-ten in den Bereichen Farbdiskrimination und Farbperzeption identifiziert [36,37,38,39]. Auch elektrophysiologische Untersuchungen (Elektroretinographie), weisen auf Störungen der retinalen Funktionen hin.…”

“…Auch elektrophysiologische Untersuchungen (Elektroretinographie), weisen auf Störungen der retinalen Funktionen hin. Das Ausmaß der Sehstö-rung korreliert mit der Schwere motorische Defizite und kann z. T. durch dopaminerge Substitutionstherapie verbessert werden [37]. Derzeit ist allerdings noch unklar, ob diese Sehstörung den motorischen Defiziten der ParkinsonKrankheit vorausgehen.…”

Loss of color vision during long-term treatment with pramipexole

“…One putative reason for impaired parkinsonian color vision is reduced dopamine levels in dopamine containing amacrine cells of the retina and/or other alterations of the visual pathway [1]. Accordingly dopaminergic substitution improves impaired parkinsonian color vision [2][3][4]. Known frequent and rare side effects of dopamine substituting drugs are nausea, hypotension, psychosis, sleep disturbances, edema, retroperitoneal fibrosis and rarely loss of visual acuity; however, a loss of color vision due to antiparkinsonian drugs is not reported in the literature to the best of our knowledge [5,6].…”