Static and acuity profile perimetry at various adaptation levels

Effects of target size, eccentricity and background luminance were determined for static and acuity profile perimetry in the central 30 degree radius of the visual field. Reductions in target size produced decreases in sensitivity for both functions, with acuity profiles (resolution sensitivity) being more affected than static profiles (detection sensitivity). At photopic background luminances, detection sensitivity was greatest at the fovea and progressively declined with increased eccentricity; lower background fovea. Resolution sensitivity for small targets (20/80 or less) exhibited a rapid decline with increasing eccentricity that was relatively independent of background luminance, whereas large targets (20/125 or greater) revealed findings similar to the detection sensitivity results. The relative contributions of rods and cones to threshold visual responses thus appear to depend on the type of visual task, target size, eccentricity, background luminance and their interactions. These data provide a comparison basis for future evaluations of patients with photoreceptor dysfunction.