Näkökenttätutkimuksen

Näkökenttätutkimus, or visual field testing, is a method used in ophthalmology and neurology to assess a person's visual field, which is the total area where objects can be seen. It measures how well a person can see to the sides, above, and below their direct line of sight. This test is crucial for diagnosing and monitoring a variety of eye conditions such as glaucoma, retinitis pigmentosa, optic nerve damage, and other neurological disorders that can affect vision.

The most common type of visual field testing is automated perimetry. During this test, the patient is seated in front of a machine with a curved screen. The patient focuses on a central point, and small lights of varying brightness are presented in different locations on the screen. The patient is instructed to press a button whenever they see a light. The machine records which lights the patient sees and which they miss, creating a map of their visual field.

Another method is manual or Goldmann perimetry, which is performed by an examiner who moves a target of light into the patient's visual field from different directions and notes when the patient first sees it. This method allows for more qualitative assessment and can be useful for patients who have difficulty with automated machines.

Abnormal results in a visual field test can indicate damage to the optic nerve, visual pathways in the brain, or other parts of the visual system. The pattern of vision loss can help ophthalmologists pinpoint the location and cause of the problem, guiding treatment and management strategies to preserve remaining vision. Regular visual field testing is often recommended for individuals with known conditions that can affect their sight.