Quadrantanopia

Definition
noun, plural: quadrantanopias
A visual field defect characterized by a loss of vision in a quarter section of the visual field
Supplement
Visual field defects occur when retina, optic pathways or the visual cortex are damaged.¹ Examples of visual field defects include (1) anopia, which is blindness in one eye, (2) hemianopia, which is the loss of vision in half of the visual field of one eye, and (3) quadrantanopia, which is the loss of a quarter of the visual field. Quadrantanopia may affect one or both eyes. It can be caused by a lesion, particularly, in the temporal and parietal lobes although it is more commonly associated with occipital lobe lesions.² The condition may be homonymous or heteronymous depending on which portions of the visual field of each eye are affected. Homonymous quadrantanopia is one in which the same portion in each eye is affected. In contrast, heteronymous quadrantanopia is one in which the quadrant portions affected are not the same. It may also be classified as inferior or superior, or either binasal or bitemporal. It may also be described as crossed when the upper quadrant in one eye and the lower quadrant in the other eye have lost vision.
Synonym(s):

• quadrantic hemianopia
• quadrant anopia
• quadrantanopsia

Reference(s):

¹ Porth, C. & Hannon, R. (2010). Porth pathophysiology: concepts of altered health states. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins. p.1357.

² Kolb, B & Whishaw, I.Q. (2008). Human Neuropsychology, Sixth Edition. Worth Publishers. p.361