Table 1.

(A) PCA clinical features and (B) diagnostic red flags (adapted from [1, 10••, 42])

(A) Clinical and cognitive features
Insidious onset
Gradual progression
Prominent early disturbance of visual ± other posterior cognitive functions
Absence of tumour and significant vascular disease include stroke, afferent visual cause or identifiable cause (e.g. kidney failure) sufficient to explain symptoms.
Space perception deficit
Simultanagnosia
Object perception deficit
Constructional dyspraxia
Environmental agnosia
Oculomotor apraxia
Dressing apraxia
Optic ataxia
Alexia
Left/right disorientation
Acalculia
Limb apraxia (not limb-kinetic)
Apperceptive prosopagnosia
Agraphia
Homonymous visual field defect
Finger agnosia
Relatively spared anterograde memory, speech, non-visual language, executive function and behaviour

(B) Diagnostic red flags
Repeated appointments with eye specialists
Repeatedly changing prescription of glasses
Misdiagnosed with ocular condition
May undergo unnecessary surgeries (e.g. cataract removal)
May be diagnosed as having a functional disorder
Tendency to miss letters on an acuity chart — especially crowded letters based on location (flanked by adjacent letters) or visual similarity (e.g. F flanked by L and E)
Unexplained difficulty with Ishihara plates (which may be susceptible to difficulties perceiving fragmented objects/objects amongst visual clutter)
Inconsistent apparent homonymous field defects
Becoming lost in familiar and unfamiliar environments