Abstract
Purpose:
Undetected intraocular pressure (IOP) peaks seem to be related to glaucoma progression. Performing a diurnal IOP curve profile (IOP-CP) has been used to determine IOP fluctuations; nevertheless, IOP-CP is considered cumbersome for both the patient and the physician. An alternative method of detecting IOP spikes is the water-drinking test (WDT). The purpose of our study is to investigate the acceptance of patients with primary open-angle glaucoma (POAG) of two diagnostic tests of IOP fluctuation: WDT vs. IOP-CP.
Methods:
A sample of non-consecutive patients with POAG was recruited from public hospital in Guadalajara, Mexico. A signed consent form was obtained from all participants. The study protocol was granted by the local IRB. After a comprehensive ophthalmological assessment, patients underwent in random order a WDT and an IOP-CP. The WDT consisted of an initial IOP reading, intake of one liter of water in less than five minutes; after drinking water, IOP was measured every 15 minutes for 1 hour. IOP-CP was done at 3 different moments (8 AM, 1 PM and 7 PM); at least 2 consistent IOP measurements (differences < 3 mm Hg) with a calibrated tonometer had to be got. The same observer masked to previous IOP measurements, performed all tonometries. Participants were also asked to determine which test would prefer as an initial test; an acceptance score was also requested to each patient using a visual analogue scale (0 to 10).
Results:
Fifty two candidates were screened and 38 (27 female and 11 male; mean age = 63.7 ± 8.6 yrs.) were included to participate in the study. Significant differences in WDT were found at two time points (30 and 60 min vs. baseline; p=0.001). Nine subjects (23.6%) had clinically significant changes (IOP peaks larger than 4 mm Hg). The IOP-DC showed no significant differences regarding mean IOP values in none of the moments; only two individuals (5.3%) had clinically significant differences. Patients preferred the WDT (92.8%) as an initial test score and acceptance score of such test was 9.8 ± 0.6 which was significantly better (p = 0.0001) than IOP-CV (8.1 ± 2.3).
Conclusions:
Our results demonstrate that WDT outperform IOP-DC to detect significant changes in IOP; furthermore, patients prefer the WDT as a diagnosis test and give a better score of acceptance as compared to the IOP-CD.
Keywords: 568 intraocular pressure •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques •
496 detection