Perimetry

Perimetry

Perimetry is the systematic measurement of visual field function (the total area where objects can be seen in the peripheral vision while the eye is focused on a central point). The two most commonly used types of perimetry are Goldmann kinetic perimetry and threshold static automated perimetry.

A visual field test (perimetry) will detect loss of peripheral vision and provide a map of that loss which will be helpful in diagnosing the cause of the loss.

Visual field testing is most frequently used to detect signs of glaucoma damage to the optic nerve. In addition, visual field tests are useful for detection of central or peripheral retinal diseases of the retina, eyelid conditions such as drooping (ptosis), optic nerve damage and disease, and conditions affecting the visual pathways from the optic nerve to the area of the brain (occipital cortex) where this information is processed into vision.

Diagnosis

  • Screening for glaucoma: Peripheral vision loss is often an early and subtle sign of glaucoma. Visual field tests are helpful in detecting vision loss and making the diagnosis of glaucoma, and repeat testing is used to monitor treatment.
  • Screening and testing for lid droop (ptosis)
  • Testing for toxicity from certain medications (for example, screening for toxicity from hydroxychloroquine [Plaquenil], which can affect the central retina)
  • Measuring the extent of retinal diseases, such as retinitis pigmentosa
  • Detecting conditions affecting the optic nerve, such as tumors, injury, poor circulation or stroke, optic neuropathy, swelling of the optic nerve (optic neuritis), compression from swelling in the eye socket or orbit, and severe nutrient deficiencies
  • Detecting conditions that affect the visual pathways from the optic nerves to the occipital lobe of the brain, including tumors, inflammatory disease, increased intracranial pressure, injury, poor circulation, or stroke
  • Testing for malingering behavior or factitious disorders