Short- and long-term phasing of intraocular pressure in stable and progressive glaucoma

AIMS: To evaluate short- (ST) and long-term (LT) intraocular pressure (IOP) in patients with stable (SG) and progressive glaucoma (PG). MATERIALS AND METHODS: Fifty-two patients with treated glaucoma received a baseline 24-hour IOP curve and, every 6 months for 2 years, office-hour curve plus visual field test. Based on field changes, they were divided into 24 SG and 28 PG. ST and LT IOP mean, peak and fluctuation (standard deviation of measurements) were calculated. Parameters determining progression were evaluated by logistic regression. RESULTS: At ST, SG and PG, respectively, had mean IOP of 16.8 ± 2.2 and 15.3 ± 1.8 mm Hg; peak of 19.7 ± 3.3, 17.4 ± 2.3 mm Hg; fluctuation of 2.3 ± 1.2, and 1.6 ± 0.6 mm Hg. LT parameters did not change in SG, whereas a significant increase of mean (+1.0 ± 1.5 mm Hg, p = 0.05), peak (2.0 ± 2.4 mm Hg, p = 0.0002), and fluctuation (0.5 ± 1.1 mm Hg, p = 0.008) occurred in PG. Mean, peak, and fluctuation were correlated, except mean and fluctuation in the long term. Association with progression was shown for change in mean IOP between ST and LT, and ST peak. CONCLUSIONS: SG and PG may show different IOP parameters when intensively measured at baseline and follow-up. Mean IOP change between ST and LT periods and ST peak were the parameters associated with progression.