The purpose of this study was to compare high-pass resolution perimetry (HRP) test results with clinical optic disc measurements and semi-quantitative retinal nerve fiber layer (RNFL) estimates. HRP reflects the separation of functional ganglion cells in the retina, and estimates a 'Functional Channel Fraction (FCF)' index that expresses the number of functional ganglion cells relative to average normal. FCF was statistically highly significantly correlated both with the overall and diffuse RNFL score (r = -0.63, P less than 0.0001) and with the neuroretinal rim area (r = 0.44; P less than 0.001). This suggests that HRP is a useful psychophysical test to assess optic nerve integrity in glaucoma.