Table 1.

Comparison of oculo-visual dysfunction in Parkinson’s disease (PD) and other parkinsonian syndromes

Disorder
Feature	PR	PD	PD-Dem	DLB	PSP	CBD	MSA
Visual acuity		±		–		–
Colour vision	±	+	+	+			–
Stereopsis	+	+	+
Contrast sensitivity		+			+		–
Motion detection		+
Visual fields		+		+		+
Eyelid mobility		+			+	+	+
Blink reflex		+				+
Pupil reactivity	±	+	+	+	+		+
Fixation					+		+
Saccadic EM		+	+	+	+	+	+
Smooth pursuit EM	+	+	+		+	+	+
Nystagmus		+on			+on	+on	+
VOR					+	±	+
ERG		+f		+f	+		±
Cortical VEP		+Ch		–		–
Visuo-spatial function	+	+	+	+		+	–
Visuo-motor adaptation	+	+
Reading ability				+	+		+
Object recognition		+fa		+
Visual hallucinations		+	+	+	+r	+r	+r

Abbreviations: Disorders: PR = Prodromal phase of disease, PD = Parkinson’s disease without dementia, PD-Dem = Parkinson’s disease with dementia DLB = Dementia with Lewy bodies, PSP = Progressive supranuclear palsy, CBD = Corticobasal degeneration; MSA = Multiple system atrophy, Visual features: EM = Eye movements, EP = Evoked potential, ERG = Electroretinogram, VEP = Visual evoked potential; Symbols: Unaffected (–), Affected (+), Controversial (±). Superscripts: Ch = Chromatic VEP, f = Flash VEP, fa = Faces, on = Abnormal optokinetic nystagmus, r = rarely present Blanks indicate where limited available data to assess visual function. PD dementia data include only features where there is evidence suggesting exacerbation with developing cognitivedysfunction.