Walsh & Hoyt: Perimetry and Visual Field Testing

Perimetry and visual field testing have been clinical diagnostic test procedures for more than 150 years. Although instrumentation and testing strategies have changed dramatically over this time, the basic principle underlying conventional perimetry has remained the same. Detection sensitivity is determined for a number of locations throughout the visual field using a small target presented against a uniform background. The loss of sensitivity at various visual field locations serves as a noninvasive marker for identifying pathology or dysfunction of the visual pathways. The ability of perimetry to provide helpful clinical information has been responsible for its long-term use as a diagnostic procedure. Because perimetry can provide information about both the likely anatomic locus and disease process or processes for afferent system abnormalities, it remains a vital part of the neuro-ophthalmologic evaluation.