Reliability in perimetry

As perimetric instrumentation becomes more sophisticated, patient reliability emerges as an important limiting factor in testing. Modern instrumentation for threshold and suprathreshold perimetry incorporate up to five separate indicators of patient reliability. For these perimetric methods, patient reliability is enhanced with specific techniques such as refractive correction, control of pupil size, and actively monitoring patient responses. With the manual (Goldmann) perimeter and the tangent screen, special statokinetic techniques help in both assessment and enhancement of patient reliability. In screening perimetry, reliability is assessed by analyzing the relative number, relative location, and repeatability of misses. Reliability in confrontation perimetry is both assessed and enhanced by using finger-counting and color-naming techniques. Review of the ophthalmic literature on perimetry shows how the various methods of patient reliability assessment and enhancement can be applied in the clinic.