title: Intraocular pressure dynamics with prostaglandin analogs: a clinical application of the water-drinking test.
abstract: OBJECTIVE
  To evaluate the clinical applicability of the water-drinking test in treatment-naive primary open-angle glaucoma patients.
  
  
  METHODS
  Twenty newly diagnosed primary open-angle glaucoma patients and 20 healthy controls were enrolled in this prospective study. The water-drinking test was performed at baseline and 6 weeks and 3 months after prostaglandin analog treatment. Peak and fluctuation of intraocular pressure (IOP) measurements obtained with the water-drinking test during follow-up were analyzed. Analysis of variance for repeated measures and paired and unpaired t-tests were used for statistical analysis.
  
  
  RESULTS
  The mean baseline IOP values in patients with primary open-angle glaucoma were 25.1±4.6 mmHg before prostaglandin analog treatment, 19.8±3.7 mmHg at week 6, and 17.9±2.2 mmHg at month 3 after treatment. The difference in mean baseline IOP of the water-drinking tests was statistically significant (P<0.001). At 6 weeks of prostaglandin analog treatment, two patients had high peak and fluctuation of IOP measurements despite a reduction in baseline IOP. After modifying treatment, patients had lower peak and fluctuation of IOP values at month 3 of the study.
  
  
  CONCLUSIONS
  Peak and fluctuation of IOP in response to the water-drinking test were lower with prostaglandin analogs compared with before medication. The water-drinking test can represent an additional benefit in the management of glaucoma patients, especially by detecting higher peak and fluctuation of IOP values despite a reduced mean IOP. Therefore, it could be helpful as a supplementary method in monitoring IOP in the clinical practice.
authors.affiliation: Ophthalmology Department.
authors.forename: Pelin
authors.initials: P
authors.lastname: Özyol
authors.affiliation: Ophthalmology Department.
authors.forename: Erhan
authors.initials: E
authors.lastname: Özyol
authors.affiliation: Biostatistics Department, Faculty of Medicine, Mugla Sitki Kocman University, Mugla, Turkey.
authors.forename: Ercan
authors.initials: E
authors.lastname: Baldemir
keywords: glaucoma; intra-ocular pressure fluctuation; intraocular pressure; prostaglandin analog; water-drinking test