The differential diagnosis between primary and postneuritic optic nerve atrophy is sometimes decided by one or two minute anatomic details. Attention is paid chiefly to the presence of the physiologic cup, to the visibility of stippling of the lamina cribrosa, to the absence of connective tissue on the disk or vessels, to the integrity of the disk outlines and to the regular distribution of pigment around the nerve. If deviations from the normal under these headings are noted they are presumptive evidence that an inflammation of the nerve has antedated its atrophic state.
But how much right on the basis of statistical inquiry does one have in assuming that the nerve should possess a well defined cup or a visible lamina cribrosa, that the borders of the disk should be sharp, without adjacent pigmentary derangement, or that connective tissue should be absent ?
If only one nerve is atrophic a comparison