Computerized disc analysis (optic nerve-head analyzer, Rodenstock) and automated perimetry (Octopus 2000R, program G1) were used for the longitudinal monitoring of 25 subjects with elevated intraocular pressure (47 eyes). The mean follow-up time was 17.9 months (range, 12-30 months). The average number of disc examinations per eye during the follow-up period was 4.4 (range, 3-7). A progressive decrease in neuroretinal rim area was observed in 8 of 47 eyes. This continuous decrease is nonphysiological and must be interpreted as a valid sign of ongoing glaucomatous damage. It apparently precedes visual field defects, as all eyes showing continuous loss of neuroretinal rim area have had normal visual fields up to the present. Of the remaining 47 eyes, 21 showed a slight increase or no change in neuroretinal rim area. These eyes obviously did not suffer from progressive glaucomatous nerve-head damage during the follow-up period. A total of 18 eyes showed either considerable fluctuations or only a slight decrease in neuroretinal rim area; no decision can yet be made as to whether or not these eyes actually suffered glaucomatous damage.