näkökenttäpuutoksia

Näkökenttäpuutokset, also known as visual field defects, are impairments in a person's normal visual field. The visual field is the entire area that a person can see at any given moment without moving their eyes or head. Defects can manifest as blind spots (scotomas), areas where vision is blurred or absent, or as a loss of peripheral vision. These defects can affect one or both eyes and can vary in size, shape, and location.

The causes of näkökenttäpuutoksia are diverse and often relate to damage or dysfunction within the visual pathway. This pathway begins at the retina and extends through the optic nerve, optic chiasm, optic tracts, lateral geniculate nucleus, and finally to the visual cortex in the brain. Conditions affecting any part of this pathway can lead to visual field loss. Common causes include glaucoma, which damages the optic nerve; strokes, which can damage the visual cortex; optic neuritis, an inflammation of the optic nerve; and brain tumors that may compress visual pathways. Retinal diseases, such as macular degeneration or diabetic retinopathy, can also cause central or paracentral visual field defects.

Symptoms of näkökenttäpuutoksia depend on the location and extent of the defect. A small blind spot might go unnoticed, while larger or peripheral defects can cause difficulties with tasks like reading, driving, or navigating familiar environments. For example, a loss of peripheral vision might lead to bumping into objects or not seeing people approaching from the side. Diagnosis typically involves a visual field test, such as perimetry, which maps out the boundaries of a person's visual field and identifies any areas of reduced sensitivity or absence of vision. Early detection and diagnosis are crucial for managing the underlying cause and, where possible, mitigating the impact of the visual field defect.