HIGH-PASS RESOLUTION PERIMETRY AND AGE-RELATED LOSS OF VISUAL PATHWAY NEURONS

The normal, age-related decline of results of high-pass resolution perimetry (HRP) predicts a loss of approximately 9 000 retino-cortical neural channels per year of age, or about 1 channel each hour. Previously published counts of numbers of neurons in the optic nerve indicate a loss of approximately 5 000 neurons per year. The HRP results can be accounted for by postulating that neurons are lost at the same rate also in the geniculo-striate visual pathway.