topography of visual fields

Question 1

three general characteristics of visual field defects

Answer 1

chiasmal and retrochiasmal lesions are 1) bilateral 2)show up in central field 3)line up along the vertical. Exception to all three is in the occipital lobe

Question 2

general principle of congruity

Answer 2

the more anterior (tract, geniculate) the lesion the more incongruous the visual field. Post lesions (radiation, occipital lobe) are congruous

Question 3

steep field defect vs shallow

Answer 3

steep- defect remains same regardless of isopter (vascular origin). Shallow- defect changes with size of isopter (edema or hemrrhage)