What do you need to know about Computerized perimetry?
Computerized perimetry (also known as visual field) tests the entire peripheral (lateral) visual field.
This test is commonly used to detect any signs of damage to the optic nerve due to glaucoma. In addition, perimetry tests are also useful for detecting central or peripheral retinal disease, eyelid disorders such as ptosis or drooping eyelid, optic nerve disease and diseases affecting visual pathways in the brain.
At the first visit to the ophthalmologist with symptoms of glaucoma, a perimetry test will be performed, obtaining results that the ophthalmologist can analyze during the examination. This initial test allows the ophthalmologist to form a starting point and then, at regular intervals, additional perimetry tests are carried out and comparisons are made with the initial test. Without regular monthly tests, it is very difficult to accurately monitor progress. Several tests performed for 6 months are a very important part of assessing and monitoring your condition as they can detect any subtle changes in vision. Some medications you take may also affect your central vision, so you may need to have more regular field tests for this reason.
What does Computerized perimetry involve?
The operating principle of perimetry can be outlined using the automatic static perimetry procedure as a template. The perimeter is linked to a virtual program on the computer. The program tests the 30 central degrees of the visual field using a grid spaced six degrees apart.
The perimetry test is performed on each eye in turn, fully covered to avoid errors. You will be asked to look straight ahead to avoid testing central vision. A perimetry test (visual field test) measures all areas of vision, including lateral or peripheral vision.
To perform the test, you will sit in a chair and look through the inside of a bowl-shaped instrument called a perimeter. As you look into the center of the bowl, lights flash. Press a button each time you see a flash. A computer records the time and place of each flash and whether you pressed the button when the light flashed at that point.
At the end of the test, the printed results show whether there are any areas of your vision where you did not see the flashes of light. These are areas of vision loss. Peripheral vision loss is often an early sign of glaucoma.
What can be diagnosed by Computerized perimetry?
Computerized perimetry (visual field) is most commonly used in the diagnosis of glaucoma, and to supplement other tests, for cataract, optic neuropathy, retinopathy of pigmentation, etc. It is recommended as a routine preventive investigation after the age of 45-50 years, especially if the patient suffers from ocular hypertension. A perimetry test can help find certain patterns of vision loss. This may mean that there is some type of eye disease. It is very useful in finding early changes in vision caused by nerve damage due to glaucoma. Periodic perimetry tests can be used to see if glaucoma treatment prevents further vision loss. The amount of peripheral vision loss is related to the amount of optic nerve damage.
A perimetry test performs a detailed record of visual fields. Basic information, descriptions or drawings can be compared with future test results.
The Tomey AP-2000 perimeter, used in Dr. Holhoș clinics, offers a modern eye tracking system, LED technology, controlled digital camera, pupil measurement and custom testing programs.