J Manipulative Physiol Ther. 1998 Jan; 21(1): 32-6.
Wall perimetry in chiropractic.
Macquarie University, School of Chiropractic, Sydney, Australia.
BACKGROUND: Wall perimetry is a method of examination that led to the initial appreciation of the "tunnel vision information." The visual field loss that wall perimetry indicates generally defines the overall characteristics of the dysfunction associated with 'tunnel vision.' Wall perimetry is an inexpensive, yet sensitive, preliminary screening test for perception abnormality in the outermost periphery of vision. OBJECTIVE: To describe wall perimetry. The term "wall perimetry" denotes a simple preliminary method of examining the visual fields of chiropractic patients. DISCUSSION: The test is described with reference to photographs. The patient stands 1 m from the corner of a room and is instructed to look directly at the junction of the walls, with the head remaining still and gaze fixed. Standing behind the patient, the examiner projects a target of light onto the wall and moves it until it is seen by the subject. CONCLUSION: Chiropractors are encouraged to test appropriate patients by wall perimetry before spinal manipulation therapy. On the basis of existing experience, detection of patients with visual field loss is to be expected. From that point, formal examination of the visual fields using kinetic or static perimetry apparatus is recommended to further verify the "tunnel vision" discovery.