Goldmann visual field (GVF) tests an individual’s complete field of vision. Visual field testing may also be called perimetry. A normal patient can see 60 degrees both nasally and superiorly, 110 degrees temporally, and 75 degrees inferiorly. The accuracy of a Goldmann visual field depends on both the patient taking the test and the perimetrist giving the test. The patient must be able to understand the test, maintain fixation and respond correctly. The perimetrist must have experience in keeping the testing consistent.
The Goldmann visual field tests the entire visual field, one eye at a time by plotting points along circles called isopters. Each isopter is color-coded to the size and intensity of the stimulus used. The patient is shown lights of varying size and intensity. During Goldmann perimetry, dimmer stimuli are used for testing the very center of vision with the intensity increasing as the peripheral portions of the field are tested.
Goldmann visual field testing is preferred over automated visual field testing for patients with low vision or with a central scotoma (blind spot) because fixation is easier to monitor when a human perimetrist performs the test. Due to the patient’s difficulties with fixation, a human perimetrist is better able to map the size and shape of the central scotoma.
Goldmann visual fields are essential to Neuro-Ophthalmology. They are used when patients are unable to perform a Humphrey visual field (HVF) due to fatigue, slower cognitive skills, low reliability, poor fixation, or decreased vision. In addition, the Goldmann visual field is helpful when the visual defect is located or extends beyond the central 30 degrees (peripheral visual field defect).
Goldmann visual field testing is a valuable test to detect and follow the progression of scotomas in a variety of ocular diseases such as glaucoma. The key to interpreting a Goldmann visual field is to consider the normal hill of vision, and how it compares with the patient’s results. The doctor identifies patterns and observes any change with repeated tests.
Goldmann visual fields are useful in monitoring progression or recurrence of disease and help a doctor with treatment for conditions such as idiopathic intracranial hypertension (IIH), optic neuropathy from multiple sclerosis, pituitary adenomas, and other sellar lesions. They are used as a screening tool for toxic optic neuropathy from medications such as ethambutol and vigabatrin. Doctors may continue current treatment or alter course depending on repetitive Goldmann visual field tests.
