The Morphological Difference Between Glaucoma and Other Optic Neuropathies

The defining features of a 'glaucomatous' optic neuropathy include 'glaucomatous' 'cupping' which is difficult to describe and therefore phenotype except when 'deep' cupping is present and is accompanied by some degree of excavation of the rim tissues beneath Bruch's Membrane Opening (BMO) and/or the anterior scleral canal opening. Discussion of what constitutes 'glaucomatous' cupping are made difficult by the fact that 'cupping' is a clinical term which is used to describe optic nerve head (ONH) structural change in all forms of optic neuropathy, however 'cupping' is also used as a synonym for the pathophysiology of glaucomatous damage to the ONH. Because the clinical and pathophysiologic contexts for 'cupping' are seldom clarified there is a confusing literature regarding the presence, importance and meaning of 'cupping' in a variety of disorders.