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Abstract #18996 Published in IGR 3-1
Chromatic and achromatic defects in patients with progressing glaucoma
Pearson P; Swanson WH; Fellman RLVision Research 2001; 41: 1215-1227
To evaluate the pattern of losses associated with glaucomatous injury in patients with progressing glaucoma, functional losses were examined in 14 patients with progressing glaucoma using tests for which detection should be selectively mediated by one of three psychophysical mechanisms. Red-on-white increments, blue on-white increments and critical flicker frequency were used to isolate the responses of the red-green chromatic mechanism, the blue-on chromatic mechanism, and the high-frequency flicker achromatic mechanism. For the 3.1° circular stimuli, chromatic defects were found in a greater number of the patients with glaucoma than were achromatic defects. The authors evaluated these defects in terms of two existing hypotheses: preferential loss and reduced redundancy. The greater sensitivity to glaucomatous injury of chromatic tests, compared to achromatic tests, found in this and other studies and the apparent discrepancy between anatomical and psychophysical studies can be parsimoniously explained by differences in cortical summation of ganglion cell responses for the chromatic and achromatic pathways.
Dr W.H. Swanson, Department of Clinical Sciences, SUNY College of Optometry, 33 West 42nd Street, New York, NY 10036, USA
Classification:
6.6.3 Special methods (e.g. color, contrast, SWAP etc.) (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)