Observations concerning the course of glaucoma.

Four cases with glaucomatous damage to the optic nerve head preceding a rise in intraocular pressure from normal or borderline to high values, are reported. The question of whether such cases are exceptional or typical and, therefore, best explained by a coincidence of diseases or by one disease going through successive stages is discussed on the basis of 10 further cases from a population study. Many clinicians claim that there are two groups of patients: a large one with 'ordinary' glaucomas supposedly caused by high intraocular pressures and a small one with low tension glaucomas presumed to have low perfusion pressures for other reasons. This classification circumvents the discussion on etiology and gives theoretical support to conventional treatment. Accumulated clinical observations indicate, however, that it should not be accepted without discussion. We describe here a few selected cases with glaucomatous damage to the optic nerve head preceding a rise in the intraocular pressure from normal or borderline to high values.