Normal tension glaucoma: the value of predictive tests

Duration of the hypotensive effect of prostaglandin analogues measured with the water drinking test in glaucoma patients

OBJECTIVE

To measure the magnitude and duration of the hypotensive effect of two prostaglandin analogues in glaucoma patients using the water drinking test (WDT).

METHODS

Patients received latanoprost or travoprost every 24 h and then every 48 h. Untreated WDT were performed at 7 am and with treatment 12, 36 and 44 h after the last dose; intraocular pressure (IOP) peak, fluctuation and the difference between peak and isolated IOP measurements at consultation times were calculated.

RESULTS

Forty-one eyes of 21 patients with primary open-angle glaucoma were included; 22 eyes received latanoprost, and 19 received travoprost. Mean untreated isolated IOP was 17.20 standard deviation (S.D.) 3.73 and 16.95 S.D. 2.61 mmHg and peak pressure 22.45 S.D. 2.91 and 21.58 S.D. 3.79 mmHg, for the latanoprost and travoprost groups, respectively. With treatment, peak pressure was reduced by 22.64% and 20.29% at 12 h, 18.44% and 14.64% at 36 h and 16.17% and 14.46% at 44 h, respectively. The fluctuation without treatment was 4.36 and 5.11 mmHg, and with treatment at 12 h was reduced to 2.77 and 2.89 mmHg, increasing again at 36 and 44 h.

CONCLUSIONS

A hypotensive effect was evident up to 44 h after the last dose of latanoprost and travoprost, similar for the two drugs and decreasing over time. IOP fluctuation was only reduced at 12 h.

Correlation between intraocular pressure obtained with water drinking test versus modified diurnal tension curve measurement in pseudoexfoliation glaucoma

PURPOSE

The aim of this paper was to study the correlation and agreement between the intraocular pressure (IOP) peak value and fluctuations detected with the modified diurnal tension curve (mDTC) and the water drinking test (WDT) in pseudoexfoliation glaucoma (XFG) patients.

METHODS

This prospective observational study enrolled 42 eyes of 42 XFG patients. The IOPs were measured at 2-h intervals from 8 am to 4 pm with a Goldmann applanation tonometer by a single observer to establish the mDTC. The WDT was then performed between 4 and 5 pm on the same day and the IOP was measured 4 times at 15-min intervals after water ingestion. The IOP_peak, IOP_mean, IO _min, and IOP_fluctuation were measured with both the mDTC and WDT. The paired sample t test, Spearman's correlation coefficient and Bland-Altman plots were used for statistical analysis.

RESULTS

The mean age of the 42 patients consisting of 24 females and 18 males was 66.9 ± 6.8 years, and the mean central corneal thickness was 517.7 ± 29.1 µm. The mean values with the mDTC and WDT measurements were 15.05 ± 2.75 mmHg and 17.17 ± 3.25 mmHg (p ≤ 0.0001, r = 0.884) for IOP_mean, 16.76 ± 3.45 mmHg and 18.92 ± 3.94 mmHg (p ≤ 0.0001, r=0.787) for IOP_peak, and 13.61 ± 2.56 mmHg and 15.11 ± 2.84 mmHg (p ≤ 0.0001, r=0.824) for IOP_min, respectively, and a positive correlation was present between these values.

CONCLUSION

There was a positive correlation between the peak, minimum, and mean IOP values determined using the mDTC and WDT in treated XFG patients. WDT can be used as an alternative in the assessment of the IOP in these patients as a more practical method.

Intraocular Pressure Changes after Water Drinking Test in Surgically Treated Primary Congenital Glaucoma

Purpose

To assess intraocular pressure (IOP) changes after the water drinking test (WDT) in patients with primary congenital glaucoma (PCG).

Methods

In this prospective interventional study, 20 eyes of 20 patients with PCG were included. All patients had undergone trabeculotomy. Six out of twenty eyes had received a glaucoma drainage device (GDD) implantation. IOP was measured using an air-puff tonometer at baseline, and 15, 30, 45, and 60 min after WDT. The repeated-measures analysis of variance test was used to compare the mean IOPs at different time points.

Results

The mean ( ± standard deviation) of participants' age was 9.9 ± 2.7 years (range, 6 to 16 years), and 8 (40%) participants were male. The mean IOPs at baseline and 15, 30, 45, and 60 minutes after the WDT were 15.8 ± 3.7, 18.6 ± 3.4, 19.0 ± 3.8, 17.9 ± 3.8, and 16.9 ± 3.5 mmHg, respectively (P < 0.001). Pairwise comparisons revealed that the mean IOPs after 15 and 30 min were significantly greater than the baseline IOP (P < 0.001 and P = 0.002, respectively); however, the difference in mean IOPs after 45 and 60 min were not statistically significant from the baseline IOP. The averages of IOP peak and IOP fluctuation after the WDT were 20.0 ± 3.5 and 4.2 ± 2.9 mmHg, respectively. IOP fluctuation in those who underwent trabeculotomy alone was twice that of those with GDDs, but the difference was not statistically significant (5.0 vs 2.5 mmHg; P = 0.08).

Conclusion

In patients with PCG, WDT induced significant IOP elevation 15 and 30 min after the test, which returned to pre-test values after 45 min.

Water Drinking Test: Intraocular Pressure Changes after Tube Surgery and Trabeculectomy

PURPOSE

To study the effects of filtration surgeries (tube and trabeculectomy) on changes in intraocular pressure after a water-drinking test.

METHODS

In this prospective, non-randomized, comparative clinical study, 30 patients who had tube surgery and 30 age- and sex-matched trabeculectomy patients underwent a water-drinking test. Only one eye of each patient was included. The baseline intraocular pressure was ≤21 mmHg in all enrolled eyes with or without adjunctive topical medications. After the water-drinking test, the intraocular pressure was measured and recorded at 15, 30, 45, and 60 minutes and the results were compared between the two groups.

RESULTS

In both groups, intraocular pressure significantly increased from baseline at all measured time-points (P < 0.001). In the trabeculectomy group, the average intraocular pressure increased from 14.8 ± 2.9 to 18.8 ± 4.7 mmHg at 30 minutes, but decreased at 60 min (18.0 ± 5.2 mmHg). In the Tube group, intraocular pressure increased incrementally until the last measurement (14.2 ± 3.9, 18.8 ± 5.6, and 19.7 ± 6.0 mmHg at baseline, 30, and 60 minutes, respectively). The end-pressure difference (intraocular pressure at 60 minutes vs. baseline) was significantly greater in the tube group (5.6 ± 3.6 mmHg; 41% change) than in the trabeculectomy group (3.2 ± 4.7; 23% change; P = 0.03).

CONCLUSION

Intraocular pressure significantly increased after the water-drinking test in both the groups. Intraocular pressure started to decline 30 minutes after the water-drinking test in the trabeculectomy group, while it continued to increase up to 60 minutes in the Tube group. This finding may have implications regarding the efficacy or safety of the procedures in advanced glaucoma patients.

Predictive Value of the Water Drinking Test and the Risk of Glaucomatous Visual Field Progression

PURPOSE

The purpose of this is to test the hypothesis the intraocular pressure (IOP) peaks during a stress test [the water drinking test (WDT)] can estimate the risk of future visual field progression in treated primary open-angle glaucoma (POAG) patients.

PATIENTS AND METHODS

Design: Prospective, longitudinal study.

SETTING

Clinical practice.

STUDY POPULATION

Treated POAG patients whose IOP was ≤18 mm Hg and who had no IOP-lowering interventions between the date of the WDT and the last eligible visual field.

INTERVENTION

At baseline examination, patients underwent the WDT and were then followed at regular intervals with office-based IOP measurements and visual field testing.

MAIN OUTCOME MEASURE

Cox-proportional hazards survival analysis testing the predictive value of IOP peaks during the WDT versus IOP measurements during office hours on visual field progression.

RESULTS

A total of 144 eyes of 96 patients with baseline visual field damage ranging from mild to severe followed for a mean of 28 months were analyzed. In the multivariable analysis adjusting for potential confounders, higher IOP peaks during the WDT were predictive of future visual field progression (hazard ratio=1.11; 95% confidence interval, 1.02 to 1.21; P=0.013). The average and peak IOP during office hours over the same follow-up period were not significantly associated with progression (P=0.651 and 0.569, respectively).

CONCLUSIONS

IOP peaks detected with the WDT were predictive of future visual field progression in a treated POAG population. This stress test could be a useful tool for risk assessment in daily practice.

The Water-Drinking Test Revisited: An Analysis of Test Results in Subjects with Glaucoma

PURPOSE

The Water-Drinking Test (WDT) has been shown to predict the diurnal IOP change. This study evaluates the factors that may affect the WDT results.

METHODS

This study was conducted on 203 glaucoma patients who had undergone trabeculectomy (53) or tube surgery (31), or had a medically controlled open-angle (82) or closed-angle (37) glaucoma. IOP was measured at baseline and then every 15 minutes over a one-hour period after drinking water. The main outcome measures were IOP change (increase in IOP from baseline) at all measurement time points, IOP peak (highest IOP after drinking water), IOP fluctuation (difference between IOP peak and baseline), and assessing the association of these IOPs with a patient's demographic and management modalities.

RESULTS

The mean age of the participants was 54±18 years, and 113 (56%) were male. Female patients showed greater IOP fluctuation than males (7.28 vs. 5.92 mm Hg; P=0.016), and a greater IOP peak (22.7 vs. 20.1 mm Hg; P=0.001). The observed associations between gender and IOP changes were only significant in <50 years. IOP at 60 minutes was greater in tube than trabeculectomy (5.6 vs. 3.1 mm Hg; P=0.007). The number of topical medications showed a direct independent association with IOP changes (P<0.001). Compared to other classes of topical medications, latanoprost showed lower WDT-IOP profile (P=0.0003).

CONCLUSIONS

WDT-IOP change was diminished in subjects on latanoprost, and was greater in females <50 years, and those on greater number of medications.

Applications of the water drinking test in glaucoma management

Intraocular pressure (IOP) peaks and means have been considered important factors for glaucoma onset and progression. However, peak IOP detection depends only on appropriated IOP checks at office visits, whereas the mean IOP requires longitudinal IOP data collection and may be affected by the interval between visits. Also, IOP peak assessment is necessary to verify if the peak pressure of a given patient is in target range, to evaluate glaucoma suspect risk, the efficacy of hypotensive drugs and to detect early loss of IOP control. The water-drinking test has gained significant attention in recent years as an important tool to evaluate IOP peaks and instability. The main objective of this review was to present new findings and to discuss the applicability of the water-drinking test in glaucoma management.

Intraocular pressure dynamics with prostaglandin analogs: a clinical application of the water-drinking test

AIM

To evaluate the clinical applicability of the water-drinking test in treatment-naive primary open-angle glaucoma patients.

METHODS

Twenty newly diagnosed primary open-angle glaucoma patients and 20 healthy controls were enrolled in this prospective study. The water-drinking test was performed at baseline and 6 weeks and 3 months after prostaglandin analog treatment. Peak and fluctuation of intraocular pressure (IOP) measurements obtained with the water-drinking test during follow-up were analyzed. Analysis of variance for repeated measures and paired and unpaired t-tests were used for statistical analysis.

RESULTS

The mean baseline IOP values in patients with primary open-angle glaucoma were 25.1±4.6 mmHg before prostaglandin analog treatment, 19.8±3.7 mmHg at week 6, and 17.9±2.2 mmHg at month 3 after treatment. The difference in mean baseline IOP of the water-drinking tests was statistically significant (P<0.001). At 6 weeks of prostaglandin analog treatment, two patients had high peak and fluctuation of IOP measurements despite a reduction in baseline IOP. After modifying treatment, patients had lower peak and fluctuation of IOP values at month 3 of the study.

CONCLUSION

Peak and fluctuation of IOP in response to the water-drinking test were lower with prostaglandin analogs compared with before medication. The water-drinking test can represent an additional benefit in the management of glaucoma patients, especially by detecting higher peak and fluctuation of IOP values despite a reduced mean IOP. Therefore, it could be helpful as a supplementary method in monitoring IOP in the clinical practice.

Selective Laser Trabeculoplasty Reduces Intraocular Pressure Peak in Response to the Water Drinking Test

PURPOSE

To determine the effect of selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) peak and fluctuation induced by the water drinking test (WDT) in patients with open-angle glaucoma and ocular hypertension.

METHODS

Patients with open-angle glaucoma or ocular hypertension underwent the WDT before and after SLT within a 12-month period. No other changes to therapeutic regimen were permitted. IOP was measured with a Goldmann applanation tonometer at baseline and every 15 minutes for 45 minutes following a fluid challenge of 800 mL over 15 minutes. Baseline, peak, and percentage fluctuation in IOP from baseline were compared using a repeated measures analysis of variance with Bonferroni adjustment.

RESULTS

Twenty eyes from 20 patients were included in this study. The median patient age was 73±15 years (interquartile range) and 70% of patients were female. Ten eyes (50%) had a diagnosis of primary open-angle glaucoma and 10 eyes had ocular hypertension. Following SLT there was a statistically significant reduction in mean baseline IOP from 16.9±2.4 to 14.2±2.3 mm Hg (P<0.001), peak IOP from 21.9±3.7 to 16.9±3.1 mm Hg (P<0.001).

CONCLUSIONS

Patients with open-angle glaucoma and ocular hypertension treated with SLT have significantly reduced peak IOPs and fluctuation in IOP in response to the WDT.

24-hour intraocular pressure and ocular perfusion pressure in glaucoma

This review analyzes the currently available literature on circadian rhythms of intraocular pressure (IOP), blood pressure, and calculated ocular perfusion pressure (OPP) in patients with open-angle glaucoma. Although adequately powered, prospective trials are not available. The existing evidence suggests that high 24-hour IOP and OPP fluctuations can have detrimental effects in eyes with glaucoma. The currently emerging continuous IOP monitoring technologies may soon offer important contributions to the study of IOP rhythms. Once telemetric technologies become validated and widely available for clinical use, they may provide an important tool towards a better understanding of long- and short-term IOP fluctuations during a patient's daily routine. Important issues that need to be investigated further include the identification of appropriate surrogate measures of IOP and OPP fluctuation for patients unable to undergo 24-hour measurements, the determination of formulae that best describe the relationship between systemic blood pressure and IOP with OPP, and the exact clinical relevance of IOP and OPP fluctuation in individual patients. Despite the unanswered questions, a significant body of literature suggests that OPP assessment may be clinically relevant in a significant number of glaucoma patients.

Reproducibility of intraocular pressure peak and fluctuation of the water-drinking test

BACKGROUND

The water-drinking test has been used as a stress test to evaluate the drainage system of the eye. However, in order to be clinically applicable,a test must provide reproducible results with consistent measurements. This study was performed to verify the reproducibility of intraocular pressure peaks and fluctuation detected during the water-drinking test in patients with ocular hypertension and open-angle glaucoma.

DESIGN

A prospective analysis of patients in a tertiary care unit for glaucoma treatment.

PARTICIPANTS

Twenty-four ocular hypertension and 64 open-angle glaucoma patients not under treatment.

METHODS

The water-drinking test was performed in 2 consecutive days by the same examiners in patients not under treatment. Reproducibility was assessed using the intraclass correlation coefficient.

MAIN OUTCOME MEASURES

Peak and fluctuation of intraocular pressure obtained with the water-drinking test were analysed for reproducibility.

RESULTS

Eighty-eight eyes from 24 ocular hypertension and 64 open-angle glaucoma patients not under treatment were evaluated. Test and retest intraocular pressure peak values were 28.38 ± 4.64 and 28.38 ± 4.56 mmHg, respectively (P = 1.00). Test and retest intraocular pressure fluctuation values were 5.75 ± 3.9 and 4.99 ± 2.7 mmHg, respectively (P = 0.06). Based on intraclass coefficient, reproducibility was excellent for peak intraocular pressure (intraclass correlation coefficient = 0.79) and fair for intraocular pressure fluctuation (intraclass correlation coefficient = 0.37).

CONCLUSION

Intraocular pressure peaks detected during the water-drinking test presented excellent reproducibility, whereas the reproducibility of fluctuation was considered fair.

Additive intraocular pressure reduction effect of fixed combination of maleate timolol 0.5%/dorzolamide 2% (Cosopt) on monotherapy with latanoprost (Xalatan) in patients with elevated intraocular pressure: a prospective, 4-week, open-label, randomized, controlled clinical trial

PURPOSE

To evaluate the additive effect of dorzolamide/timolol fixed combination in patients under monotherapy with latanoprost.

PATIENTS AND METHODS

In this prospective, 4-week, randomized, open-label controlled clinical trial, patients with open-angle glaucoma or ocular hypertension, which presented at least 15% intraocular pressure (IOP) reduction after a minimum period of 15 days of monotherapy with latanoprost and whose IOP level was considered above the established target-IOP level were randomized to receive fixed combination of timolol/dorzolamide twice daily in one of eyes. The fellow eye was kept under monotherapy and was included in the control group. A modified diurnal tension curve (mDTC) followed by the water drinking test were performed in the baseline and week 4 visits to evaluate IOP profile between groups.

RESULTS

Forty-nine per-protocol patients were analyzed. After latanoprost monotherapy run-in period, IOP levels were significantly reduced (P<0.001) in both control and study groups to 15.34+/-2.96 mm Hg and 15.24+/-2.84 mm Hg (30.8% and 32.2% IOP reduction, respectively; P=0.552). At week 4, mean baseline diurnal IOP levels were 15.60+/-3.09 and 14.44+/-3.03 (7.4% difference; P=0.01). Mean baseline IOP modified diurnal tension curve peak after latanoprost run-in period were 17.47+/-3.68 mm Hg and 17.02+/-3.35 mm Hg (control and study eyes, respectively; P=0.530). At week 4 visit, mean water-drinking test peaks were significantly reduced in the study eye group in comparison with the control group: 19.02+/-3.81 mm Hg and 20.39+/-4.19 mm Hg, respectively (6.7% reduction; P=0.039).

CONCLUSIONS

In our sample, dorzolamide 2%/timolol 0.5% fixed combination as add-on therapy in patients with open-angle glaucoma or ocular hypertension under monotherapy with latanoprost with IOP already in mid-teens levels may further enhance pressure reduction.

Understanding the mechanism of the water drinking test: the role of fluid challenge volume in patients with medically controlled primary open angle glaucoma

BACKGROUND

To determine whether a 500-mL fluid challenge produces a different intraocular pressure (IOP) response profile compared with a 1000-mL water drinking test (WDT).

METHODS

Prospective, observer-masked, cross-over, observational study. Patients with primary open angle glaucoma were recruited from a private specialist glaucoma practice. One eye of each patient was included. Subjects were randomized to receive either a 500-mL or 1000-mL fluid challenge. Baseline IOP was recorded with a Goldmann applanation tonometer and then every 15 min for 1 h. A second WDT with the alternate volume of water was performed after a minimum washout period of 24 h. Primary statistical analysis was performed using a two-way anova repeated measures of variance with a Bonferroni post-hoc test.

RESULTS

Fifteen patients were included in this study. The mean patient age was 67.0 +/- 10.2 (SD) years, and 60% of patients were female. There was no statistically significant difference in baseline IOP between the 500-mL and 1000-mL WDTs (P = 0.11). Both fluid challenge volumes produced a statistically significant rise in IOP from baseline at 15, 30 and 45 min after water ingestion. However the mean maximum increase in IOP was less in the 500-mL WDT (3.3 +/- 1.8 mmHg [23.9%]) compared with the 1000-mL WDT (4.9 +/- 2.3 mmHg [32.5%]; P = 0.0095).

CONCLUSION

The 500-mL WDT may provide an alternative for patients who are unable to tolerate drinking 1000 mL of water. However, because the maximum IOP obtained is less, a 500-mL WDT cannot be used to directly estimate peak diurnal pressure.

Correlation between central corneal thickness and intraocular pressure peak and fluctuation during the water drinking test in glaucoma patients

OBJECTIVE

To investigate the correlation between central corneal thickness and outflow facility assessed by intraocular pressure peak and fluctuation during the water drinking test.

METHODS

Fifty-five newly diagnosed primary open-angle glaucoma patients submitted to central corneal thickness measurements and water drinking test were enrolled in this retrospective study.;. Patients were divided into three groups according to their central corneal thickness. Pearson's Correlation test was performed in the groups with lower and higher pachymetric values.

RESULTS

The mean age was 65,65 ± 28,28 years; 63,63% were female and 52,72% were caucasian. The mean central corneal thickness was 544,32 ± 36,86 µm, and the mean baseline intraocular pressure was 23,36 ± 6,26 mmHg. During the water drinking test, the mean intraocular pressure peak and mean intraocular pressure fluctuation were 30,43 ± 8,13 mmHg and 31,46 ± 18,46%, respectively. No relevant correlation was detected between the central corneal thickness and the intraocular pressure peak (r² = 0,021) or between the central corneal thickness and the intraocular pressure fluctuation (r² = 0,011). Group 1 presented a mean central corneal thickness of 505,81 ± 13,86 µm, and Group 3 was 583,55 ± 27,87 µm (p = 0,001). The mean intraocular pressure peak was 31,05 ± 9,05 mmHg and 27,83 ± 4,92 mmHg in Group 1 and in Group 3, respectively (p = 0,193). The difference of intraocular pressure fluctuation was not statistically significant between Group 1 (mean 28,47 ± 16,25%) and Group 3 (mean 33,27 ± 21,27%) (p = 0,43).

CONCLUSION

In our case series, no correlation was found between central corneal thickness and water drinking test results.

An eight-week, multicentric, randomized, interventional, open-label, phase 4, parallel comparison of the efficacy and tolerability of the fixed combination of timolol maleate 0.5%/brimonidine tartrate 0.2% versus fixed combination of timolol maleate 0.5%/dorzolamide 2% in patients with elevated intraocular pressure

PURPOSE

To compare the efficacy and tolerability of the fixed combination of timolol maleate 0.5%/brimonidine tartrate 0.2% versus fixed combination of timolol maleate 0.5%/dorzolamide 2% in patients with elevated intraocular pressure (IOP) over 8 weeks.

PATIENTS AND METHODS

This 8-week, multicentric, interventional, randomized, open-label, parallel group study was conducted at 4 centers in Brazil and 1 center in Argentina. Patients with open-angle glaucoma or ocular hypertension were randomized to receive bilaterally fixed combination of brimonidine/timolol maleate 0.5% or fixed combination of dorzolamide 2%/timolol 0.5% twice daily at 8:00 AM and 8:00 PM. A modified diurnal tension curve (8:00 AM, 10:30 AM, 02:00 PM, and 4:00 PM) followed by the water drinking test (WDT), which estimates IOP peak of diurnal tension curve, were performed in the baseline and week-8 visits. Adverse events data were recorded at each visit.

RESULTS

A total of 210 patients were randomized (brimonidine/timolol, n=111; dorzolamide/timolol, n=99). Mean baseline IOP was 23.43+/-3.22 mm Hg and 23.43+/-4.06 mm Hg in the patients treated with brimonidine/timolol and dorzolamide/timolol, respectively (P=0.993). Mean diurnal IOP reduction after 8 weeks were 7.02+/-3.06 mm Hg and 6.91+/-3.67 mm Hg, respectively (P=0.811). The adjusted difference between groups (analysis of covariance) at week 8 was not statistically significant (P=0.847). Mean baseline WDT peak was 27.79+/-4.29 mm Hg in the brimonidine/timolol group and 27.68+/-5.46 mm Hg in the dorzolamide/timolol group. After 8 weeks of treatment, mean WDT peaks were 20.94+/-3.76 mm Hg (P<0.001) and 20.98+/-4.19 (P<0.001), respectively. The adjusted difference between groups (analysis of covariance) was not statistically significant (P=0.469). No statistical difference in terms of adverse events was found between groups.

CONCLUSIONS

Both fixed combinations were capable of significantly reducing the mean diurnal IOP, mean diurnal peak, and mean WDT peak after 8 weeks of treatment. Also, both fixed combinations are well tolerated with few side effects.

Correlation between the water drinking test and modified diurnal tension curve in untreated glaucomatous eyes

OBJECTIVES

To investigate the correlation and agreement between the intraocular pressure peaks detected during the water drinking test and the modified diurnal tension curve in untreated glaucomatous eyes.

INTRODUCTION

It has been suggested that the intraocular pressure peaks detected during the water drinking test predict the peaks observed during a 24-hour diurnal tension curve. A more feasible and practical test for assessing intraocular pressure peaks in glaucomatous eyes during office hours would be of great clinical utility.

METHODS

This was a prospective study involving open angle glaucoma patients without anti-glaucoma medication submitted to the modified diurnal tension curve and water drinking test on the same day. The intraocular pressure peaks during the water drinking test and the modified diurnal tension curve were reported and compared. Statistical analysis was performed to assess the correlation and agreement between intraocular pressure peak measurements.

RESULTS

The correlation between intraocular pressure peaks during the water drinking test and modified diurnal tension curve was significant and strong (Pearson's Correlation Coefficient r=0.780, p<0.0001). Limited agreement was observed between these measurements. Eighty-two percent of intraocular pressure peaks were higher during the water drinking test than the modified diurnal tension curve.

DISCUSSION

These findings suggest that the water drinking test may be used as tool to assess risk factors for glaucomatous patients.

CONCLUSION

Intraocular pressure peaks detected during the water drinking test could be used in clinical practice to both estimate the peaks observed during the modified diurnal tension curve and assess the status of the eye's outflow facility.

The relation between intraocular pressure peak in the water drinking test and visual field progression in glaucoma

AIM

To compare the results of the water drinking test between glaucomatous eyes with and without visual field progression.

METHODS

Retrospective analysis of 76 eyes of 76 open angle glaucoma patients followed for a mean period of 26.0 (SD 13.8) months. Patients were submitted to the water drinking test at the beginning of the follow up period. Reliable achromatic automated perimetry tests performed during the studied period were used to characterise visual field progression. All subjects were under clinical therapy and had an intraocular pressure (IOP) lower than 17 mm Hg monitored by isolated measurements during the follow up period. The results of the water drinking test were compared between glaucomatous eyes with and without visual field progression.

RESULTS

Twenty eight eyes reached definite visual field progression. There were no significant differences in the mean age, sex, race, basal IOP, number of antiglaucomatous drugs, initial mean deviation (MD), and corrected pattern standard deviation (CPSD) between eyes that showed visual field progression and the ones who did not progress. A significant difference of 1.9 (SD 0.6) mm Hg (p = 0.001, analysis of covariance; 95% CI 0.8 to 3.0) was observed between glaucomatous eyes that showed visual field deterioration and glaucomatous eyes that did not progress. A significant difference of 16.8% (SD 4.6%) in the mean percentage of IOP variation was also observed between the two groups (p<0.001, analysis of covariance; 95% CI 7.7 to 26.0).

CONCLUSIONS

Mean IOP peak and percentage of IOP variation during water drinking test were significantly higher in patients with visual field progression compared with patients who did not progress.

Intraocular pressure variability in patients who reached target intraocular pressure

AIM

To assess the intraocular pressure (IOP) variability in patients with primary open angle glaucoma (POAG) under clinical treatment who reached an established target pressure based on isolated office readings.

METHODS

Retrospective analysis of 65 eyes from 65 POAG patients under clinical therapy who submitted to modified diurnal tension curve (mDTC) (measurements at every 3 hours between 8 am and 5 pm) followed by a water drinking test (WDT). All subjects had established target IOP < or =15 mm Hg at 11 am or 2 pm. IOP variability during mDTC or WDT was evaluated.

RESULTS

mDTC revealed IOP measurements > or =17 mm Hg in 16 of 65 eyes (24.6%). Nine eyes (13.8%) presented values > or =18 mm Hg. The highest IOP detected by mDTC was 20 mm Hg in one patient (1.5%). WDT demonstrated IOP values > or =17 mm Hg in 32 of 65 eyes (49.2%). 22 eyes (33.8%) presented values > or =18 mm Hg after water ingestion. Moreover, IOP levels > or =20 mm Hg were observed in 14 eyes (21.5%).

CONCLUSION

A great percentage of POAG patients undergoing clinical treatment and with IOP control based on single office measurement present significantly higher IOP measurements when performing mDTC and, especially, the WDT.

Intraocular pressure fluctuations in response to the water-drinking provocative test in patients using latanoprost versus unoprostone

Impairment of outflow facility in glaucoma causes large intraocular pressure (IOP) fluctuations that have been shown to be a risk factor for disease progression. The water-drinking provocative test (WDT) has been proposed as an indirect measurement of outflow facility to compare intraocular pressure responses of glaucoma eyes to different drugs. This study was a double-masked, randomized, parallel-group clinical trial comparing the IOP fluctuations in response to the WDT in patients using latanoprost versus unoprostone. After completing a wash-out of ocular hypotensive medications, patients with primary openangle glaucoma or ocular hypertension were randomized to receive either latanoprost (N=40) or unoprostone (N=42). IOP was measured before treatment and at 8 weeks after treatment (baseline IOP for WDT), followed by the WDT. IOP fluctuations and maximum IOP after water ingestion were compared between the two groups. Analysis of covariance was used to adjust for the effects of baseline IOP and treatment efficacy. The mean percentage reduction of IOP was 27% in patients using latanoprost, as compared to 13% in patients using unoprostone (p<0.001). Patients on treatment with latanoprost had significantly less IOP fluctuations in response to the WDT, compared to patients using unoprostone. From an overall baseline IOP of 20.0 mmHg and an overall treatment efficacy of 20%, the mean+/-standard error of the mean (SEM) of the IOP fluctuation during the WDT was 5.3+/-0.4 mmHg in the unoprostone group, and 3.6+/-0.4 mmHg in the latanoprost group (p=0.005, ANCOVA). This could represent an additional benefit of latanoprost over unoprostone in controlling the intraocular pressure of glaucomatous patients.

Comparison of latanoprost with fixed-combination dorzolamide and timolol in adult patients with elevated intraocular pressure: an eight-week, randomized, open-label, parallel-group, multicenter study in Latin America

BACKGROUND

The newer ocular hypotensive agents available to treat glaucoma and ocular hypertension (OHT) include latanoprost, a prostaglandin F(2alpha) analogue, and the fixed combination of dorzolamide hydrochloride, a carbonic anhydrase inhibitor, and timolol maleate, a beta-blocker.

OBJECTIVE

The aim of this study was to compare the efficacy and tolerability of latanoprost with that of the fixed combination of dorzolamide and timolol over 8 weeks.

METHODS

This interventional, 8-week, randomized, open-label, parallel-group study was conducted at 18 centers in 6 Latin American countries. Patients with unilateral or bilateral primary open-angle, pigmentary, or exfoliative glaucoma or OHT were randomized to receive latanoprost, 1 drop in the affected eye QD (evening), or fixed-combination dorzolamide/timolol, 1 drop in the affected eye BID (morning and evening). Medications were self-administered, 1 drop per affected eye. At baseline and week 8, intraocular pressure (IOP) was measured 3 times each at 8:30 am, 10:00 am, 2:00 pm, and 5:00 pm and after the water-drinking test, which estimates the IOP peak of diurnal tension curve, performed following the 5:00 pm IOP assessment. The primary efficacy outcome was change in diurnal IOP (the mean of IOP measurements) from baseline to week 8. Adverse effect (AE) data were recorded at each visit.

RESULTS

A total of 229 patients were randomized (latanoprost, n = 112; dorzolamide/timolol, n = 117). Mean baseline diurnal IOP values were similar between the 2 groups. Mean (SD) diurnal IOP reductions at week 8 before the water-drinking test were 6.9 (3.0) mm Hg for the latanoprost group and 6.4 (3.2) mm Hg for the dorzolamide/timolol group. Mean IOP values were similar at all time points except at 5:00 pm, when levels were significantly lower in latanoprost-treated patients (P = 0.025). After the water-drinking test, the increase in IOP values was similar between groups at baseline but lower in latanoprost-treated patients at week 8 (adjusted difference, 1.08 mm Hg; P = 0.012). Fewer patients treated with latanoprost reported ocular or systemic AEs (P = 0.025 and P < 0.001, respectively).

CONCLUSIONS

In this study of patients with unilateral or bilateral primary open-angle, pigmentary, or exfoliative glaucoma or OHT IOP reductions generally were similar between treatment groups, except at 5:00 pm, when the mean IOP level was significantly lower in latanoprost-treated patients. Latanoprost was better tolerated than fixed-combination dorzolamide and timolol.

Intraocular pressure fluctuations in medical versus surgically treated glaucomatous patients

The purpose of this study was to compare the IOP fluctuations in the daytime tension curves of glaucoma patients under ocular hypotensive therapy with those of patients previously submitted to trabeculectomy. We also evaluated the IOP peaks and fluctuations for the same patients in response to the water-drinking test (WDT). The study included 30 primary open-angle glaucoma (POAG) patients using ocular hypotensive medications and with no history of previous intraocular surgery (medical group), and 30 POAG patients previously submitted to one or more trabeculectomies though taking no medication at the time of the study (surgical group). All patients were submitted to a diurnal tension curve--DTC (8:30-17:00/3-hour intervals) followed by the WDT. The IOP peak and IOP fluctuation during the diurnal tension curve were significantly greater in the medical group than in the surgical group. The same was observed following the WDT. From an overall baseline IOP of 10.6 mmHg, the mean IOP change following the WDT was 13% in the surgical group and 40% in the medical group. Patients submitted to trabeculectomy have less TOP fluctuations during the diurnal tension curve and following a water-drinking provocative test. This effect could represent an additional benefit of surgery in controlling the intraocular pressure of glaucomatous patients.

Current status of prostaglandin therapy: latanoprost and unoprostone

Latanoprost, a prostaglandin F(2alpha) analog prodrug, and unoprostone, an analog of a prostaglandin metabolite, have been shown to be effective in decreasing intraocular pressure when used alone or in combination with other ocular hypotensive agents. The increase in the uveoscleral outflow and some of the side effects are probably FP-receptor mediated, which may account for some differences between the cited drugs. This article reviews the recent literature available on the clinical efficacy of these prostanoids, as well as the studies directly comparing these drugs.

The pros and cons of different prostanoids in the medical management of glaucoma

The prostaglandin analogs are new exciting drugs added to the therapeutic armamentarium for patients with glaucoma. Several studies have evaluated the ocular hypotensive properties and side effects of latanoprost in different forms of glaucoma. This drug, seems to be the most effective intraocular pressure (IOP)-reducing agent currently available, and has a low incidence of ocular and systemic side effects. Fewer data are available regarding unoprostone, but the IOP-reducing effect of this drug seems to be comparable or slightly inferior to that of timolol and it produces fewer side effects. When compared with unoprostone, latanoprost has been shown to effect a greater reduction in IOP. A major drawback to the use of prostaglandin analogues is the lack of long-term experience such as that currently available for other classes of agents.

Intraocular pressure and central visual field of normal tension glaucoma

AIM

To study whether damage in the central 30 degrees field of normal tension glaucoma (NTG) is relatively heterogeneous or homogeneous with respect to intraocular pressure (IOP) related damage.

METHODS

Using the results of Humphrey perimeter examinations, the central 30 degrees field was divided into four subfields; superior and inferior hemifields excluding the caecocentral field (30-2 program) and superior and inferior 10 degrees hemifields (10-2 program). In 103 NTG cases, the intraindividual bilateral difference in the mean of total deviations (mean TD) in the four subfields was analysed by multiple linear regression to correct the effects of factors other than IOP. Explanatory variables were the intraindividual bilateral difference in the mean of clinic IOP (IOPmean), that in the ratio of area of peripapillary atrophy corresponding to each subfield to disc area, and that in myopic refraction.

RESULTS

The intraindividual bilateral difference in the mean TD was significantly and negatively correlated with that in IOPmean in three of the above four subfields (p < 0.005) and correlation tended to be negative (p = 0.07) in the superior 10 degrees hemifield.

CONCLUSIONS

Diffuse IOP related damage was suggested in the central 30 degrees field of NTG; greater extent of the damage in the above four subfields was correlated with higher mean IOP. The present findings may have clinical implications.

Effect of trabeculectomy on visual field performance in central 30 degrees field in progressive normal-tension glaucoma

PURPOSE

The authors studied the effects of trabeculectomy on the time course of central 30 degrees visual field performances in progressive normal-tension glaucoma (NTG).

METHODS

Patients with NTG who had clear ocular media and were adequate performers on the 30-2 program of Humphrey Perimeter were prospectively followed with periodic field testing. Trabeculectomy using an antimetabolite was indicated when the slope of a line fitted to the time course of the mean deviation (MD), MD slope, was significantly negative. The time courses of MD and mean of total deviations (mean TD) in four subfields, superior and inferior arcuate and superior and inferior cecocentral fields, were analyzed using the mixed linear model.

RESULTS

In progressive NTG, 21 eyes of 21 cases with postoperative follow-up of 2 years or more, intraocular pressure averaged 16 mmHg, MD averaged -13.5 dB, and MD slope averaged -1.48 dB/year preoperatively; 2 years after surgery, they averaged 9.2 mmHg, -13.6 dB, and +0.13 dB/year, respectively. Trabeculectomy had a significant beneficial effect on the time course of MD and mean TD in the superior and inferior arcuate and superior cecocentral fields, which showed significant preoperative deterioration. The mean TD in the inferior cecocentral field showed no significant time change during the period studied.

CONCLUSION

For patients with NTG in whom the MD slope is significantly negative, trabeculectomy may have beneficial and diffuse effects on further deterioration of the visual field.