High-pass resolution perimetry

Abstract

Minimum angles of resolution were measured along the vertical visual field meridian in normal subjects, using high-pass spatial frequency filtered ring targets at different contrast levels. Results were correlated with Curcio and Allen's (J Comp Neurol 1990; 300:5) data on human retinal ganglion cell densities in corresponding retinal locations. Previously reported resolution measurements along the horizontal meridian were also analyzed. A close proportionality through the origin was observed for all contrasts. Analysis of the regression coefficients indicated that resolution of high-contrast, high-pass ring targets depends on a substantial fraction of parvocellular retino-cortical neural channels. Magnocellular channels have a much too small spatial density to explain results at high contrast but may be involved at lower contrast levels.

Key Words:

• visual field
• perimetry
• resolution
• retinal ganglion cells
• neural channels