What is computerized field testing?

The visual field is the entire area one can see. It includes central and peripheral (side) vision. A visual field test can detect problems with vision in any part of the visual field. The test provides a map of any loss in this which will be helpful in diagnosing the cause of the loss

What are the indications for this test?

Visual field testing is done in people suspected to have glaucoma. These persons may have one or more of the following:

• Suspicious changes in the eye when seen with slit lamp microscope.
• High eye pressure
• People with family history of glaucoma
• Diabetics
• Myopes i.e. Short sighted individuals
• Increasing age.

Visual fields is also done for people having neurological problems.

Why is this test important in the management of glaucoma?

At first, open angle glaucoma has no symptoms. Vision stays normal, and there is no pain. Subtle changes that occur in the field are one of the earliest changes that occur. Thus by checking visual field we are able to diagnose glaucoma early before much damage occurs to the optic nerve.

What is the next step once glaucoma is diagnosed?

If the glaucomatous changes are minimal eye drops are all that is required. If these are applied as instructed then we can prevent further sight loss. The intraocular tension needs to be monitored very closely once treatment is started. Once the pressure has been adequately controlled then tension and fields have to be repeated once in 6 months.

How frequently does the test need to be done?

The field analyzer quantifies the ocular damage. The data from the test is preserved in the computer. When the test is repeated the computer will compare between the fields and highlight any area of the field which has worsened or improved. This will enable you ophthalmologist to adjust your medication so your vision is preserved. The frequency at which the test has to be repeated depends on the degree of damage that has already occurred and the degree of glaucoma control. Usually in positive cases field has to be repeated after 6 months.