Visual Pathway Disorder
- Damage to the visual pathway somewhere between optic nerve and visual cortex, including optic chiasm, optic tract, and optic radiations
- Site of damage often localizable by ophthalmoscopy, pupil reactions, and pattern of visual field defects
- Patients may report monocular or binocular blurred, blank, dim, dark, or sparkling vision
- Optic nerve damage may be accompanied by swollen optic disc
- Unilateral or asymmetric optic nerve damage produces afferent pupil defect
- Lesions of optic nerve produce nerve fiber bundle visual field defects
- Lesions of optic chiasm usually produce bitemporal hemianopias
- Lesions of optic tracts, optic radiations, and visual cortex usually produce homonymous hemianopias
- See patterns of visual field loss and how they localize lesions of visual pathway
- Refer to ophthalmologist or neuro-ophthalmologist with urgency that matches speed of onset of visual loss
- Some disorders are reversible, especially if detected early
