Reproducibility of water drinking test performed at different times of the day.
OBJECTIVE
To evaluate the reproducibility of water drinking test (WDT) performed at different times of the day, in primary open angle glaucoma (POAG) patients and normal individuals.


METHODS
Fifteen patients with POAG and 30 normal individuals underwent three WDTs at different times of the day (7 AM, 12 PM, and 5 PM) on 3 different days. Test results in POAG patients and normal individuals were compared. Agreement and correlation of intraocular pressure (IOP) baseline levels, peak levels, and IOP change (peak IOP--baseline IOP) on tests performed at different times were evaluated. Only right eye measurements were analyzed.


RESULTS
Mean baseline IOP, peak IOP and IOP change were significantly higher in POAG patients than in normal individuals, at all time intervals (p<0.05). The Bland-Altman analysis demonstrated limits of agreement for IOP peak levels and IOP changes larger than the clinically acceptable (>3 mmHg), even though Pearson's test revealed good correlation among the results.


CONCLUSIONS
The mean IOP peak and mean IOP change observed during WDT are significantly higher in POAG patients than in control individuals. Low levels of agreement among WDTs performed at different times of the day suggest a poor reproducibility of WDT, which may limit its applicability for the diagnosis and follow-up of glaucoma.
Medina
Flavio Mac Cord
FM
Department of Ophthalmology, Universidade Estadual de Campinas, Campinas, SP, Brazil. fmaccord@hotmail.com
Rodrigues
Fabrício Kafury Pereira
FK
Filho
Paulo de Tarso Ponte Pierre
Pde T
Matsuo
Tiemi
T
Vasconcellos
José Paulo Cabral de
JP
Costa
Vital Paulino
VP
D004326:Drinking; D004812:Epidemiologic Methods; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013997:Time Factors; D014867:Water
D014867:Water