In the article by Harris et al1 recently published in the ARCHIVES, the authors address several major questions including the effect of aging on optic nerve head perfusion. They state that "In humans preliminary evidence suggests that aging fails to alter basal perfusion of the optic nerve head . . . ," citing an article by Groh et al.2 They failed, however, to cite our article, "Optic Nerve Head Blood Speed as a Function of Age in Normal Human Subjects."3 In that article, we reported a statistically significant 4.7% per decade decrease in optic nerve head capillary blood speed in subjects between the ages of 31 and 76 years. We pointed out that if there is a narrowing or a reduction in the number of optic nerve head capillaries with age, then the decrease in optic nerve head blood flow would be even greater than the decrease in blood speed measured by our technique.
Feke GT, Rizzo JF. Regulation of Retinal and Optic Nerve Blood Flow. Arch Ophthalmol. 1999;117(7):978-979. doi: