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RETINOTOPIC MAP:. View from above. Perimetric testing to Diagnose field defects. Each eye’s field of View (visual field) is mapped out Can light be detected throughout the visual field?. Perimetric Map shows lower right quadrant blindness (quadrantanopsia) in both eyes.
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View from above Perimetric testing to Diagnose field defects
Each eye’s field of View (visual field) is mapped out Can light be detected throughout the visual field?
Perimetric Map shows lower right quadrant blindness (quadrantanopsia) in both eyes
Hemianopia Deficit in 1/2 VF (homonymous: both eyes)
Scotoma field defect within a quadrant
Quadrantanopsia defect affects 1/4 VF
Gordon Holmes (1919) maps the visual field onto primary visual cortex creating an early look at the Retinotopic map.
Gordon Holmes (1919) - original retinotopic map: • Correlated Visual Field Defects with lesion locus • Features of Map: Crossed organization • Left 17 --> RVF • Right 17 --> LVF Fovea: Disproportional representation • cortical magnification Inverted organization • Lower calcarine --> Upper VF • Upper calcarine --> Lower VF • NOTE: Each visual cortex represents a visual field NOT an eye.
Sensitive areas are “magnified” Field of View Fovea Cortical Map of Visual Field