Optometry and vision science : official publication of the American Academy of Optometry | 2021
Deployment of the Water Drinking Test and iCare HOME Phasing for Intraocular Pressure Profiling in Glaucoma Evaluation.
Abstract
SIGNIFICANCE\nIntraocular pressure (IOP) profiling is an important component of the glaucoma examination. Two techniques for profiling are the water drinking test (WDT) and iCare HOME phasing, but the correlations between techniques and their ease of deployment have not been studied. These questions are important in determining suitability for clinical deployment.\n\n\nPURPOSE\nTo compare the IOP results of the water drinking test (WDT) and iCare HOME phasing in patients with suspected or newly diagnosed glaucoma.\n\n\nMETHODS\nNinety-eight consecutive patients attending a glaucoma clinic underwent IOP profiling using both techniques. For the WDT, patients ingested 10 mL/kg body weight of water following a baseline applanation IOP measurement, then underwent serial IOP measurements approximately every 15 minutes, ceasing after 30 minutes of consecutive measurements within 3 mmHg of baseline. Patients successfully certified for self-administration of the iCare HOME were loaned the instrument for one week and instructed to take four measurements per day.\n\n\nRESULTS\nTwenty-seven (28%) patients successfully obtained 4 measurements per day using iCare HOME, and 96 (98%) patients were able to complete the water drinking test. IOP profiles showed no difference between the time for peak IOP and across nearly all IOP parameters obtained from profiling except for the standard deviation of IOP measurements obtained using the iCare HOME (P = .005). There were moderate correlations between peak IOPs obtained using each technique (r = 0.67, P = .001, right eye; r = 0.66, P = .002 left eye), but no correlation between the daily range (iCare HOME) or peak-trough difference (WDT) (r = 0.21, P = .28, right eye; r = 0.27, P = .02, left eye). Bland-Altman analysis returned similar results for peak and range.\n\n\nCONCLUSIONS\nIOP profiling using both techniques can reveal the peak IOP, and these measurements are strongly correlated. Most patients were unable to complete the iCare HOME according to manufacturer recommendations. Clinicians should select the most appropriate technique for each patient.