Atlas of Ophthalmology

Homonymous Hemianopia, Complete Visual Field Defect, Humphrey Visual Field

Homonymous Hemianopia, Complete Visual Field Defect, Humphrey Visual Field
Patient is 83 year old man with a history of atrial fibrillation, myocardial infarction, kidney disease. On confrontational visual fields, a defect was detected and prompted a formal visual field. The left homonymous hemianopia was revealed at that time. A hemianopia can be congruous or complete. In this case, the image reveals a complete left hemianopia. A temporal crescent is absent, this tells us the lesion is likely to be occipital. Macular sparing is absent, this tells us the lesion is likely to be occipital. This lesion points to a parietal lesion, which can be confirmed with OKN asymmetry (pursuit problems to the side of the lesion). Complete hemianopias localizes the lesion retrochiasmal, but they cannot tell us where the lesion is present. The lesion can be present in the optic tract, optic radiations of parietal lobe or occipital cortex. Cogan's Dictum can help us localize the lesion. Cogan's Dictum states: 1. Homonymous hemianopia plus asymmetric OKN=likely mass lesion, parietal lobe 2. Homonymous hemianopia plus symmetric OKN= likely vascular infarction, occipital lobe
Luviano, Damien, M.D., Joslin Diabetes Center SETMA, Beaumont, USA; Morvant, Kenneth, , Harmony Science Academy, Beaumont, USA; Garza, Arturo, , University of Houston, Houston, USA
H53.4
Cérebro
blind spot, visual field, stroke,
8725
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