The time-course of intraocular pressure in timolol-treated and untreated glaucoma suspects

We studied the behavior of intraocular pressure in glaucoma suspects randomly selected to receive either topical timolol or no treatment over the course of a long-term prospective follow-up study. All patients who after six years of follow-up showed no localized field defects or disk changes, or whose pressures were not dangerously increased (24 treated and 22 untreated patients), were included in the present study. Overall, the two groups showed an increase in pressure followed by a gentle leveling off and a decrease toward the end of the follow-up period. The pressure-time curves of the two groups were parallel and vertically separated by 4.94 mm Hg. When pressure-time relationships were determined in individual patients, the categorical group differences were not statistically significant. Our results suggest that most glaucoma suspects did not exhibit a random time-course of intraocular pressure and that the effect of treatment was simply to lower the pressure-time curve of the treated group by a fixed level throughout the six-year follow-up period.