Abstract
Purpose :
Mean IOP, peak IOP and magnitude of fluctuation have been used as predictors for disease deterioration. Peak IOP (pIOP) as determined by the water-drinking test (WDT) has been shown to be an indicator for the likelihood of progression and efficacy of hypotensive agents. On other respect, corneal hysteresis (CH) is also considered a powerful predictor of glaucoma progression. This study evaluates IOP and CH as variables that may predict glaucoma progression when a WDT is performed by an Ocular Response Analyzer of third generation (ORA G3).
Methods :
This study was conducted on 93 glaucoma patients (35 of them with structural / functional findings of disease progression) who had undergone a WDT under a strict protocol (3-hour fasting, one liter of pure water ingested within a 5-minute period, IOP measured at baseline and then every 15 minutes over a one-hour period after drinking water, at a fixed time of the day. The main outcome measures were IOP / CH change at all measurement time points, pIOP, IOP fluctuation, and assessing the association of these IOPs with a patient’s demographics and their condition of non-progressors versus progressors.
Results :
The mean age of the patients was 59.3 ± 9.5 years (non-progressors) and 64.8 ± 7.1 years (progressors; P = 0.001). Female proportion was almost equally represented in both groups (46.5% and 51.4%, respectively). Mean number of ocular hypotensive drugs were also signficantly different between groups (2.1 vs. 4.1, P=0.021). Progressors demonstrated significantly larger mean IOP fluctuation than non-progressors (9.5 ± 2.1 mm Hg vs. 4.1 ± 1.8 mm Hg; P=0.001), and a greater mean IOP peak (25.4 ± 4.2 mm Hg vs. 18.3 ± 5.9 mm Hg; P=0.001). Regarding CH, progressors showed significantly larger mean change than non-progressors (6.7 ± 2.3 vs. 3.2 ± 2.0 mm Hg; P=0.001). The greater VFI value the larger the IOP peak (R= 0.68, P=0.023). IOP at 30 minutes had the highest IOP values as well as the lowest CH values in both groups.
Conclusions :
Peak IOP, IOP / CH changes were greater in patients with a demonstration of disease progression as compared to non-progressors. A WDT performed with an ORA device seems to be a feasible method and can add a practical predictor of glaucoma progression.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.