Techniques and developments in automated perimetry: a review

Abstract

The development of automated perimetry represents one of the major opportunities for clinical advancement over the last 30 years. Compared with the data obtained from equivalent manual procedures, the technique now makes feasible a rapid and reliable static threshold investigation of the visual field and, as a result, has revolutionized the potential of the visual field examination in the diagnosis of ocular and neuro-ophthalmic abnormality. Several perimeters are commercially available, each featuring a variety of stimulus parameters for investigating the visual field and a range of data reduction techniques and displays to aid the clinician in the interpretation of abnormality. The choice of stimulus, however, governs the format of the derived field and thus the efficiency of detecting and assessing a given field defect. In addition, patient-specific variables also influence the visual field profile. This review outlines the techniques used in automated perimetry. In particular, the rationale is summarized for the choice of the major stimulus parameters employed by a given perimeter, such a stimulus type, adaptation level and testing strategy. The techniques available for data display and reduction are reviewed and the extraneous factors influencing the format of the normal differential sensitivity gradient are discussed.