Visual field testing is an important part of all comprehensive eye exams. Also called perimetry testing, visual field testing is a method to measure the sensitivity to light in a patient's peripheral vision.
Visual field testing is one of the most significant diagnostic tests in the detection of glaucoma. This is because glaucoma causes a loss in peripheral vision first. However, it can also be used to detect central or peripheral retinal diseases, eyelid conditions such as ptosis, optic nerve damage and other conditions that affect the visual pathways from the optic nerve to the area of the brain where this information is processed.
Visual field testing is also an important part of monitoring people who are considered to be at risk for vision loss from disease and other problems, including those who have been diagnosed with:
There are a variety of methods that can be used to perform visual field testing, including:
Static Automated Perimetry: This is where a machine is used to quantify how well the patient is able to detect flashing lights of varying size and brightness in different areas of their visual field. The patient fixates on a central point and responds by pushing a button when they see the lights flash. Automated perimetry offers obvious advantages to manual perimetry in that stimulus presentation as well as the recording of patient responses can be standardized, leading to more reproducible results. Automated perimeter machines offer a wide variety of tests using various methods to produce many detailed analyses since it can measure not only IF the patient can percieve light, but at what intensity as well. This allows them to pick up subtle losses in peripheral vision before they become total losses of peripheral vision.
Kinetic Manual Perimetry: In kinetic perimetry, a stimulus is moved from a non-seeing area to a seeing area, and the location where the object is first seen is recorded. The targets are fixed in size and are presented along the patient’s peripheral vision, before being gradually moved inwards to determine their field of vision. The speed the stimulus is moved should be standardized, typically at 2-4 degrees per second.
Visual field testing is non-invasive, painless and doesn’t require patients to have their eyes dilated. If automated perimetry is performed, the results are presented in a series of charts that are then viewed by Dr. Kubota for analysis and interpretation. Depending on the outcome of your results, you may be recommended for further diagnostic testing which could include blood tests or an MRI. If you have been diagnosed with glaucoma, you will have several visual field tests each year, to help monitor the progression of your condition.
If you would like more information about visual field testing, or if you have concerns about your peripheral vision, please don’t hesitate to schedule an appointment with our experienced and knowledgeable eyecare team today.