title: Intraocular pressure fluctuation after water drinking test in primary angle-closure glaucoma and primary open-angle glaucoma.
abstract: BACKGROUND
  Only a few studies have assessed intraocular pressure (IOP) changes during the water drinking test (WDT) in patients with primary angle-closure glaucoma (PACG).
  
  
  OBJECTIVE
  The aim of this study is to investigate IOP changes during WDT in patients with PACG versus primary open-angle glaucoma (POAG).
  
  
  METHODS
  This was a prospective and single tertiary center study.
  
  
  METHODS
  PACG and POAG patients (n = 15 each) without prior glaucoma surgery were enrolled and subjected to WDT, wherein they consumed an amount of water proportional to their body weight within 10 min. IOP was measured at baseline and every 15 min for 1 h after water intake.
  
  
  METHODS
  Intergroup comparisons were performed using Mann-Whitney U-test for continuous variables and Chi-square test for categorical variables. Wilcoxon signed-ranks test was used for comparisons of IOP before and after water intake in the two groups. Regression analysis was used to determine factors associated with IOP fluctuations during WDT.
  
  
  RESULTS
  IOP changes over 1 h after water intake showed no significant differences between groups. The mean maximum fluctuation from baseline was 3.61 ± 2.49 and 3.79 ± 1.91 mmHg, respectively, in the PACG and POAG groups. The mean peak IOP was 19.17 ± 4.32 and 19.87 ± 3.44 mmHg in the PACG and PAOG groups, respectively. The axial length and anterior chamber depth showed no correlations with IOP fluctuations.
  
  
  CONCLUSIONS
  We found similar IOP fluctuation curves and peak IOP values in both PACG and POAG patients subjected to WDT. These findings suggest that WDT is a useful test to induce IOP peaks in both POAG and PACG patients.
authors.affiliation: Department of Ophthalmology, Chang Gung University College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Yi-Chieh
authors.initials: YC
authors.lastname: Poon
authors.affiliation: Department of Ophthalmology, Chang Gung University College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Mei-Ching
authors.initials: MC
authors.lastname: Teng
authors.affiliation: Department of Ophthalmology, Chang Gung University College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Pei-Wen
authors.initials: PW
authors.lastname: Lin
authors.affiliation: Department of Ophthalmology, Chang Gung University College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Jen-Chia
authors.initials: JC
authors.lastname: Tsai
authors.affiliation: Department of Ophthalmology, Chang Gung University College of Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Ing-Chou
authors.initials: IC
authors.lastname: Lai
mesh_terms: D000368:Aged; D003941:Diagnostic Techniques, Ophthalmological; D004326:Drinking / Q000502:physiology*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis / Q000503:physiopathology*; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014867:Water / Q000008:administration & dosage*
chemical_list: D014867:Water