Comparison of Intraocular Pressure Changes During the Water Drinking Test Between Different Fluid Volumes in Patients With Primary Open-angle Glaucoma:

Agreement between the ICare HOME Tonometer and the Goldmann Applanation Tonometer in the Assessment of the Peak Intraocular Pressure in the Water-Drinking Test

PURPOSE

To investigate the agreement between the ICare HOME tonometer and the Goldmann Applanation Tonometer (GAT) in assessing the peak intraocular pressure (IOP) during the water-drinking test (WDT).

DESIGN

Prospective cross-sectional study.

SUBJECTS

Seventy-nine eyes of 41 open-angle glaucoma patients were included in the study.

METHODS

All of the included patients underwent a training session provided by ophthalmologist specialists to use the ICare HOME tonometer. Then the IOP was first measured with the GAT (AT900; Haag-Streit) by a trained physician, immediately followed by ICare HOME tonometer (TA022, ICare Oy) measurement by the patient. Four measurements were taken with each device with 15-minute differences as established by the WDT.

MAIN OUTCOME MEASURES

The agreement and degree of correlation of the peak IOP by both tonometers were assessed.

RESULTS

The agreement between the ICare HOME and GAT was high during the WDT: the intraclass correlation coefficient (r) between the 2 methods from basal to 45 minutes: 0.94 (P < 0.001), at basal: 0.91 (P < 0.001), at 15 minutes: 0.94 (P < 0.001), at 30 minutes: 0.94 (P < 0.001), at 45 minutes: 0.95 (P < 0.001), and for peak IOP: 0.94 (P < 0.001). There was no significant difference between peak IOP with the GAT and ICare HOME (18.3 ± 4.6 [10-33] and 18.5 ± 5.0 [0-33], respectively, P = 0.533), nor between the delta of fluctuation between basal and peak IOP with the GAT and ICare HOME (3.96 ± 3.22 and 4.54 ± 3.92, P = 0.054).

CONCLUSIONS

Our study demonstrated a high agreement between the ICare HOME and the GAT during the WDT in a clinical environment with supervision.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

The relationship between intraocular pressure and glaucoma: An evolving concept

Intraocular pressure (IOP) is the most important modifiable risk factor for glaucoma and fluctuates considerably within patients over short and long time periods. Our field's understanding of IOP has evolved considerably in recent years, driven by tonometric technologies with increasing accuracy, reproducibility, and temporal resolution that have refined our knowledge regarding the relationship between IOP and glaucoma risk and pathogenesis. The goal of this article is to review the published literature pertinent to the following points: 1) the factors that determine IOP in physiologic and pathologic states; 2) technologies for measuring IOP; 3) scientific and clinical rationale for measuring diverse IOP metrics in patients with glaucoma; 4) the impact and shortcomings of current standard-of-care IOP monitoring approaches; 5) recommendations for approaches to IOP monitoring that could improve patient outcomes; and 6) research questions that must be answered to improve our understanding of how IOP contributes to disease progression. Retrospective and prospective data, including that from landmark clinical trials, document greater IOP fluctuations in glaucomatous than healthy eyes, tendencies for maximal daily IOP to occur outside of office hours, and, in addition to mean and maximal IOP, an association between IOP fluctuation and glaucoma progression that is independent of mean in-office IOP. Ambulatory IOP monitoring, measuring IOP outside of office hours and at different times of day and night, provides clinicians with discrete data that could improve patient outcomes. Eye care clinicians treating glaucoma based on isolated in-office IOP measurements may make treatment decisions without fully capturing the entire IOP profile of an individual. Data linking home blood pressure monitors and home glucose sensors to dramatically improved outcomes for patients with systemic hypertension and diabetes and will be reviewed as they pertain to the question of whether ambulatory tonometry is positioned to do the same for glaucoma management. Prospective randomized controlled studies are warranted to determine whether remote tonometry-based glaucoma management might reduce vision loss and improve patient outcomes.

Intraocular Peak Pressure in Patients under Treatment with Fixed Combination of Bimatoprost/ Timolol/ Brimonidine once Daily versus Twice Daily

PRECIS

We investigate the efficacy of triple-fixed-combination of Bimatoprost/Brimonidine/Timolol once and twice a day, demonstrating higher intraocular pressure reduction with once-a-day use, and discuss possible implications based on previous literature.

PURPOSE

To compare the efficacy of fixed combination bimatoprost-timolol-brimonidine (Triplenex ®) instilled once-daily with twice-daily in primary open-angle glaucoma.

PATIENTS AND METHODS

Randomized clinical trial at a public eye care institution. Thirty patients with primary open-angle glaucoma were followed-up for three-months. The right and left eyes of these patients were randomly assigned to once-daily, (10:00 PM) or twice-daily, (10:00 AM; 10:00 PM) regimens of fixed combination bimatoprost-timolol-brimonidine. Intraocular pressure peaks were obtained with the water drinking test before the introduction of this medication (basal WDT0), one month (WDT 1), 2 months (WDT2) and 3 months (WDT3) after starting the use of the fixed combination of Bimatoprost/ Timolol/ Brimonidine (Triplenex®). Variation from peak intraocular pressure at WDT3 to peak at WDT0 was compared within groups of two versus once daily regimen.

RESULTS

Sixty eyes of 30 patients (age 70.67±9.70▒y) were included in this study. Baseline clinical characteristics were comparable between groups. Mean reduction in peak intraocular pressure from WDT0 to WDT3 was 6.1±6.1▒mmHg (30.5%) in the eyes receiving one drop per day and 4.3 ±5.7▒mmHg (21.5%) in the eyes receiving two drops per day (P=0.023). Mean reduction in peak intraocular pressure considering all WDT was also higher in the group with once-a-day treatment (5.90±6.03▒mmHg vs. 4.46±4.28▒mmHg, P=0.006).

CONCLUSION

Fixed combination of bimatoprost 0.01%, brimonidine tartrate 0.15% and timolol maleate 0.5% once-a-day is more effective in reducing peak intraocular pressure as measured by the WDT than twice-a-day dosing.

Peak Intraocular Pressure Time during Water Drinking Test and Its Relationship with Glaucoma Severity

Purpose

To investigate the association between the time of occurrence of intraocular pressure (IOP) peaks during the water-drinking test (WDT) and visual field damage in a cohort of primary open-angle glaucoma (POAG) patients.

Methods

In this retrospective, cross-sectional study, 98 eyes from 49 consecutive POAG patients were followed in a referral clinical practice. The relationship between the time when IOP peaks occurred during the WDT and the visual field mean deviation (MD) assessed with 24-2 visual field was tested with mixed-effects models.

Results

MD value was significantly associated with the time of IOP peak occurrence (P = 0.020) when adjusting for the number of medications, but not with the IOP peak values (P = 0.238).

Conclusion

The time of IOP peaks occurrence during the WDT was associated with glaucoma severity among treated POAG patients.

Correlation and Agreement Between Water Drinking Test and Modified Diurnal Tension Curve in Untreated Glaucoma Patients in Nigeria

PURPOSE

To determine the correlation and agreement between intraocular pressure (IOP) parameters evaluated by the modified diurnal tension curve (mDTC) and the water drinking test (WDT) in primary open-angle glaucoma (POAG) in an indigenous African population.

MATERIALS AND METHODS

This was a prospective, interventional, comparative study of 50 newly diagnosed, previously untreated primary open-angle glaucoma patients at the out-patient clinic of the Eleta Eye Institute, Ibadan. A series of IOP measurements were taken 2 hourly (from 7:00 AM to 3:00 PM) for the mDTC, using Goldmann applanation tonometer. The WDT was performed thereafter. The patients drank 800 mL of water within 5 minutes, and another series of IOP measurements were taken every 15 minutes for a duration of 1 hour from the moment water was fully ingested. Both the mDTC and the WDT were performed on the same day. IOP peak, mean, and IOP fluctuations were estimated from the data collected. Comparison between the mDTC and the WDT was performed using the paired Student T test for means, Pearson correlation analysis for correlation, and Bland-Altman analysis for agreement.

RESULTS

Estimated IOP parameters were significantly higher for the WDT than for the mDTC. The average peak IOP was 27.8±4.0 mm Hg during the WDT and 24.9±3.1 mm Hg during the mDTC (P<0.001). The average mean IOP was 25.8±3.6 mm Hg during the WDT and 22.3±2.4 mm Hg during the mDTC (P<0.001). The average IOP fluctuation was higher (6.6±2.9 mm Hg) during the WDT compared with 4.7±2.0 mm Hg during the mDTC. The mean and peak IOPs were strongly correlated between the mDTC (r=0.729, P<0.001) and the WDT (r=0.658, P<0.001). IOP fluctuation, however, showed weak correlation between the mDTC and the WDT (r=0.258, P=0.709).

CONCLUSIONS

There is a strong positive correlation between IOP parameters (peak and mean IOP) estimated from the WDT and the mDTC. The peak and mean IOP can be estimated from the WDT, which is quicker, compared with the mDTC. This is more relevant in low resource settings with limited personnel, time, and resource constraints. In addition, higher IOP values were obtained from the WDT compared with the mDTC, and therefore could serve as a useful practical way to determine target peak in order to optimize IOP control in glaucoma patients.

Intraocular pressure response affected by changing of sitting and supine positions

PURPOSE

To assess the intraocular pressure (IOP) time response to change in body position from sitting to supine and from supine to sitting immediately and during rest in each position.

METHODS

Forty-four visually healthy volunteers were recruited for the study. The experiment consisted of the initial sitting position (baseline state), the subsequent lying period and the final sitting period. Both periods were 30 min long. The IOP was measured in the baseline state, immediately after each position change and then in minutes 5, 15, 25 and 30 during each period. The Icare Pro^® rebound tonometer was used.

RESULTS

The mean IOP increased after each position change (2.6 ± 2.4 mmHg after lying down and 2.1 ± 3.1 mmHg after sitting up) and then gradually decreased with time. The mean IOP was 1.41 ± 2.4 mmHg higher in the lying period than in the sitting period; the mean difference was smaller for the lower baseline (0.9 ± 2.2 mmHg) than the higher baseline (1.9 ± 2.5 mmHg). The mean IOP in the final sitting was significantly lower (2.5 ± 1.9 mmHg) than in the initial sitting position. The effect of sex was insignificant.

CONCLUSIONS

There was an immediate increase in IOP as a response to both changes in the body position and the subsequent gradual decrease with time. The IOP difference between lying and sitting position was depended on baseline.