The visual fields test is usually performed when assessing the integrity and adequate function of the Optic nerve and as part of a routine eye examination.
Visual fields may be assessed by asking the patient to cover one of their eyes while the examiner assesses the opposite eye; this method is called the confrontation visual field exam, Donderâ€™s Test. The examiner can use the tip of his finger or the end of a pen and move it in each of the four quadrants of the patientâ€™s visual field, mid-way between the patient and the practitioner, checking with the patient whether the object or finger may be seen in the periphery of each of the quadrants tested. This test is done under the assumption that the examinerâ€™s visual fields are intact.
Test findings (inc Positive & Negative results):
The visual field test, as described above, is often used as a preliminary examination to aid in the detection of visual dysfunction in central and peripheral vision. A result of which may be caused various medical conditions such as brain tumours and other space occupying lesions, neurological lesions, glaucoma, stroke, and retinal detachments.
As a preliminary screening, the Donderâ€™s test is adequate however, where a pathology is suspected, referral to an optometrist is empirical.