Comparing Hydrus Microstent(TM) to the iStent for Lowering IOP in Glaucoma Patients Undergoing Cataract Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparing Hydrus Microstent(TM) to the iStent for Lowering IOP in Glaucoma Patients Undergoing Cataract Surgery (NCT02024464), a randomized na study. The primary outcome is Unmedicated Mean Diurnal Intraocular Pressure (DIOP) at Month 12.

2. Clinical Question

The comparison concerns the pressure measured at a specified visit and under the stated wash-out condition. It is not a comparison of the devices without cataract surgery, because both arms included cataract removal and intraocular lens implantation. Nor is it a comparison of treatment effects across different glaucoma procedures: the record specifies a single implanted study eye in each arm.

The secondary questions consider the proportion of participants meeting a reduction-from-baseline criterion and the proportion whose unmedicated pressure fell within a specified range at Month 12. Those outcomes provide different views of pressure response from the primary mean. They do not replace the primary question, and their posted unadjusted comparisons need to be read with attention to uncertainty and the fact that more than one endpoint was assessed.

3. Trial Design

The registry record describes a prospective, multicenter, randomized comparison with a parallel-group model and single masking. The record does not identify who was masked. The trial status is completed. Enrollment is listed as 306, and the two treatment arms are Hydrus Microstent and iStent.

Both arms included cataract removal and implantation of an intraocular lens. After that procedure, the Hydrus arm received the Hydrus Microstent in one study eye, while the iStent arm received the iStent Trabecular Micro Bypass in one study eye. Thus, the randomized comparison is between device strategies given alongside the same cataract procedure, rather than between a device and cataract surgery alone.

The listed conditions are primary open angle glaucoma, pseudoexfoliative glaucoma, and pigmentary dispersion glaucoma. The record’s brief summary describes participants with glaucoma undergoing cataract surgery and indicates that only one eye was implanted. The endpoint description says that the primary measure used an intent-to-treat population with verifiable data at the visit. Its accompanying population text also specifies exclusions or special handling related to secondary glaucoma, pressure-lowering procedures, terminal wash-out exemptions, and missed diurnal pressure assessments for response metrics and change in pressure. The full handling details for the primary mean are not reported in the registry record.

The start is listed as 2011-08, and primary completion as 2017-03. The record gives no further description of the sequence generation, allocation concealment, masking procedures, visit schedule beyond the listed endpoint time, or adherence monitoring. The original protocol’s sample-size assumptions and statistical analysis plan are not reported in the registry record. The sample-size figures associated with the posted results are planning illustrations based on observed effects, not a description of the trial’s original design.

The primary endpoint has posted results for 139 Hydrus participants and 141 iStent participants. The safety record uses separate at-risk denominators of 154 and 152, respectively. These denominators belong to different reported outcomes and should not be treated as interchangeable. The registry record does not explain the difference in endpoint populations and safety populations.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: This reporting group includes all randomized patients (306).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat (ITT) with verifiable data at visit. ITT subjects with secondary glaucoma or pressure lowering procedures, terminal wash-out exemptions, or missed diurnal IOP assessments are counted as failures for response metrics and are assigned a zero value for change in DIOP for the effectiveness endpoints.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: All randomized subjects, regardless of actual treatment received, procedure success, or compliance to protocol inclusion/exclusion criteria. \[Intent-to-Treat (ITT)\]

6. Primary Endpoint

The registry lists the primary outcome as Unmedicated Mean Diurnal Intraocular Pressure (DIOP) at Month 12, measured over Month 12: 8 am, 12 pm, 4 pm.

The primary endpoint is unmedicated mean diurnal intraocular pressure (DIOP) at Month 12, measured in mmHg. Intraocular pressure was assessed with Goldmann applanation tonometry at 8 am, 12 pm, and 4 pm, and the three readings were averaged for the endpoint. The assessment took place after a protocol-specified wash-out period from all glaucoma medications.

A mean is useful because it describes the average pressure across the scheduled daytime assessments, giving a common continuous scale for comparing randomized groups. It uses the measured values rather than reducing each participant to a yes-or-no response category. The reported standard deviations describe the spread of pressure values around each group mean; they are not confidence intervals for the means.

The endpoint is specific to Month 12 and the stated measurement conditions. It does not by itself describe pressure at other visits, pressure while participants are taking medication, or the full pattern of pressure over every hour of the day. The registry record describes an intent-to-treat population with verifiable data at the visit, but the remainder of its population text is truncated. As a result, the precise analysis population and the handling of all missing primary endpoint measurements are not reported in the registry record.

7. Results Posted in the Registry

• iStent: mean 18.10 versus 16.90 on control; difference 1.20 (95% CI 0.10 to 2.30), standardized effect d = 0.26; z-test p = 0.033.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Percentage of Subjects With 20% Reduction From Baseline in Unmedicated DIOP at Month 12

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • iStent: 83.7% (118/141) versus 82.0% (114/139) on control; risk difference 1.7 percentage points (95% CI -7.2 to 10.5), risk ratio 1.02 (0.92–1.14); unadjusted two-proportion z-test p = 0.710.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between iStent and the control. The interval gives the range of effects that remain compatible with the data.

Percentage of Subjects With Unmedicated DIOP of Not Less Than 5 mmHg and Not More Than 18 mmHg at Month 12

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • iStent: 67.4% (95/141) versus 68.3% (95/139) on control; risk difference -1.0 percentage points (95% CI -11.9 to 10.0), risk ratio 0.99 (0.84–1.16); unadjusted two-proportion z-test p = 0.862.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between iStent and the control. The interval gives the range of effects that remain compatible with the data.

Across the two secondary endpoints, the posted group percentages are close, and neither reported unadjusted comparison provides a confidence interval that excludes zero. The pattern is broadly consistent with little separation between the arms on these particular response definitions in the posted Month 12 results. The intervals nevertheless allow for differences in either direction, so the pattern should not be interpreted as proof that the groups are equivalent.

These outcomes relate to the primary result by describing pressure response in categories rather than comparing mean pressure. The primary endpoint uses the average of three measurements as a continuous value. One secondary endpoint asks whether pressure fell by at least the stated proportion from baseline; the other asks whether the measured pressure was within a stated range. The binary endpoints can make a response criterion easier to interpret, but they do not preserve all the information in the underlying pressure values.

Because the registry record lists multiple outcomes and does not report a multiplicity plan, unadjusted secondary results carry less weight as confirmatory evidence. Testing several endpoints without accounting for their combined interpretation can make isolated results less persuasive. The record also does not report a formal analysis hierarchy that would establish how the secondary findings were meant to support or qualify the primary endpoint.

The secondary results should consequently be read as additional descriptive evidence, alongside the primary comparison, not as independent proof of a broader conclusion. Similar proportions under these definitions do not erase the primary mean difference, and the primary mean difference does not guarantee that any particular participant met a threshold response. The distinction between an average and a threshold-based proportion is central to interpreting why the endpoints need not tell precisely the same story.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Percentage of Subjects With 20% Reduction From Baseline in Unmedicated DIOP at Month 12
• Percentage of Subjects With Unmedicated DIOP of Not Less Than 5 mmHg and Not More Than 18 mmHg at Month 12

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous: it is a mean pressure on a measurement scale in mmHg. The registry reports a group mean and standard deviation for each arm, then a mean difference comparing iStent with Hydrus. In plain terms, the difference is the iStent mean minus the Hydrus mean. A positive value therefore indicates that the posted iStent mean is higher, while a negative value would indicate that the posted iStent mean is lower.

What does the standard deviation describe?

A standard deviation describes how dispersed individual observations are around their group mean. It is not a measure of uncertainty in the estimated group difference. Two groups can have similar means but substantial variation among participants, or a relatively narrow spread around their means. The standard deviations of 4.5 mmHg and 4.9 mmHg describe variation in the Month 12 measurements, rather than the precision of the treatment comparison.

What does the confidence interval add?

A confidence interval gives a range of values compatible with the observed data under the method used to construct it. For the primary comparison, the reported interval is entirely above zero. Zero represents no mean difference for the stated subtraction. The interval thus indicates that the posted data are compatible with a positive difference on this scale, while still allowing a range of possible magnitudes. An interval is not a guarantee that the true value falls inside it, and its interpretation depends on the analysis method and assumptions.

How should the p-value be read?

A p-value measures how unusual data at least as incompatible with a specified null hypothesis would be if that null hypothesis and the test assumptions held. It is not the probability that the null hypothesis is true, nor does it measure the size or practical importance of a difference. The posted primary p-value is unadjusted. The registry record does not report the full test specification or whether any prespecified adjustment was part of the original analysis.

Why are the secondary outcomes different?

The two posted secondary endpoints are binary: each participant either meets the stated definition or does not. The registry reports the percentage meeting each definition and a risk difference comparing iStent with Hydrus. A risk difference expresses the contrast between group proportions on the percentage-point scale, with the sign depending on the stated comparison order. Its confidence interval indicates the uncertainty around that contrast. When an interval includes zero, the posted data remain compatible with no group difference as well as with differences in either direction.

Converting a continuous measure into a threshold outcome can make an endpoint easier to interpret as a response criterion, but it loses detail about the actual measurements. Participants just on either side of a threshold are placed in separate categories even if their pressures are similar. Participants within the same category can have different pressure values. For that reason, a binary result and a mean result need not have matching patterns.

Why can multiplicity matter?

When several outcomes are tested, each test creates an opportunity for an apparently notable result to occur by chance under its null hypothesis. A multiplicity strategy may control how results are interpreted across tests, for example by setting a testing order or adjusting decision thresholds. The registry record does not report a hierarchy, adjustment, or other multiplicity plan. The posted secondary p-values are therefore best read as unadjusted descriptive evidence, rather than as results that account for all outcome testing.

What does over-dispersion mean generally?

For binary outcomes, a simple model may assume that the variation in observed responses follows the model’s expected variation. Over-dispersion means the data vary more than that assumption allows; if ignored, uncertainty can be understated. This is a general statistical issue, not a reported feature of this trial. The registry record does not report a model-based analysis of the secondary endpoints or an assessment of over-dispersion.

The posted numerical comparisons should be kept distinct from the planning illustrations. The comparison estimates describe the observed group results and their uncertainty. Planning illustrations ask how many participants per arm might be needed under stated assumptions to detect a chosen fraction of an observed effect. They do not add evidence about the observed trial outcomes, and they do not describe the original design unless the record explicitly says so. The original design assumptions are not reported in the registry record.

11. Confidence Intervals and Precision

The primary mean difference is reported as 1.2 mmHg, with a confidence interval that runs from 0.098 to 2.302 mmHg. Because the interval is entirely above zero, it does not include the value representing no mean difference. Its width also matters: the results are compatible with a range of magnitudes, rather than identifying one exact difference. The unadjusted p-value is 0.033, but the confidence interval gives a more direct sense of the range of effects compatible with the reported estimate.

Precision is not the same as whether a result crosses a conventional statistical threshold. A narrow interval indicates more precise estimation than a wide interval, while an interval that includes zero indicates uncertainty about the direction of a difference under that interval. Neither the interval nor the p-value says whether a difference is clinically important; the registry record does not report a clinical importance threshold for the primary endpoint.

For the secondary outcomes, the confidence intervals for the risk differences include zero. The posted percentages are close across arms, but the intervals also allow for differences in either direction. The results therefore do not establish equality or equivalence. An equivalence conclusion would require a prespecified margin and a suitable analysis, neither of which is reported in the registry record.

Precision also depends on which participants contribute to an endpoint and how missing values are handled. The primary endpoint population text is incomplete, and the registry does not report a full missing-data analysis. The posted endpoint group sizes are not the same as the safety at-risk denominators; these are outcome-specific populations, and the record does not explain their relationship. Interpretation of the confidence intervals should remain tied to the populations and methods actually reported.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size display gives planning illustrations, not a reconstruction of the trial’s original design. For these outcomes, its entries are participants per arm, not total events. The assumptions stated for the illustration are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect is the stated fraction of the observed effect. The trial’s own original design assumptions are not reported in the registry record.

The 80% power column gives the planning number of participants per arm under which the assumed design would have an 80% chance of detecting the specified effect, if the assumptions hold. The 90% power column applies the same idea with a higher chance of detection, which generally requires a larger planned group. For the primary comparison, the row planning for 100% of the observed effect lists 242 participants per arm for 80% power and 324 participants per arm for 90% power.

The rows for 75% and 50% of the observed effect illustrate a general planning principle: smaller effects are harder to distinguish from random variation and need more participants. The binary outcome illustrations likewise show larger planning requirements for their stated observed-effect fractions. These figures depend on the planning assumptions and should not be read as guarantees about what a future study will find.

The accompanying curve should be read as another view of the same planning relationship between the assumed effect and the required sample size. It does not add observed trial results. This is not observed power: the figures are prospective planning calculations based on the observed effect and stated assumptions, not a measure of the probability that the completed trial detected a real effect.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 1.200; pooled standard deviation σ = 4.706.
2. n = 2 × (1.96 + 0.842)² × 4.706² / 1.200² = 241.4, rounded up to 242 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 1.2                      # observed difference in means
sigma <- 4.70569072292858                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2024464)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 242 (80% power), 324 (90% power)
 75% of observed effect: n per arm = 430 (80% power), 575 (90% power)
 50% of observed effect: n per arm = 966 (80% power), 1,293 (90% power)
power.t.test: 242.4 
Simulated power at n = 242 per arm: 0.797 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary endpoint and two secondary outcomes, with posted comparisons for the secondary outcomes. It does not report a statistical analysis plan describing a testing sequence, family-wise error control, false-discovery control, or another multiplicity strategy. The posted p-values are unadjusted. Without a reported plan, it is not possible to determine from the registry record whether the outcomes were treated as confirmatory, supportive, or exploratory in the original analysis.

Multiplicity matters because the chance of at least one apparently unusual result can increase when several hypotheses are examined. This does not make each individual result meaningless, but it affects how strongly isolated p-values should be interpreted. The secondary results are especially important to read cautiously because they are multiple outcomes and their intervals include zero.

The registry describes an intent-to-treat population with verifiable data at the visit for the primary endpoint. It also states that participants with secondary glaucoma or pressure-lowering procedures, terminal wash-out exemptions, or missed diurnal pressure assessments are counted as failures for response metrics and assigned a zero value for change in DIOP for the effectiveness analysis. The final sentence of this population description is truncated. The complete rules for the endpoint populations and missing primary measurements are not reported in the registry record.

Details of imputation, sensitivity analyses, and the treatment of participants without verifiable endpoint data are not reported in the registry record. The record also does not explain the difference between the primary endpoint group sizes and the safety at-risk denominators. These gaps make it difficult to assess whether missingness could affect the comparisons or whether alternative handling would change the findings.

Randomization supports a comparison between assigned groups, but it does not remove the need to understand the analysis population and missing-data rules. The posted results are most directly interpreted for the measured populations and endpoint definitions in the record. Stronger claims about robustness, multiplicity-adjusted evidence, or the role of all randomized participants cannot be assessed from the available registry entries.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: uncontrolled glaucoma (2.6%), bcva loss >/= 2 lines etdrs >/= 3 months (0.7%), epiretinal membrane (0.7%), iop increase (0.7%), wet age-related macular degeneration (0.7%).

The safety figures use at-risk denominators of 154 for Hydrus and 152 for iStent. The registry lists 2 serious adverse events for Hydrus and 8 for iStent, alongside 24 other adverse events for Hydrus and 16 for iStent. Deaths are listed as 4 and 3, respectively. These are reported counts with their associated denominators; they should not be confused with the smaller group sizes reported for the primary endpoint.

The record also lists the most frequent serious adverse event terms and their percentages. “Uncontrolled Glaucoma” is listed at 2.6%; “BCVA loss >/= 2 lines ETDRS >/= 3 months,” “Epiretinal Membrane,” “IOP Increase,” and “Wet Age-Related Macular Degeneration” are each listed at 0.7%. The registry does not provide enough detail to assess event timing, duration, severity definitions, or the basis for attribution. The counts alone do not establish that a device caused an event or that one arm has a different overall safety profile.

16. What the Result Does, and Does Not, Mean

The posted primary result is a comparison of mean unmedicated DIOP at Month 12 after cataract removal and intraocular lens implantation, with one of two devices implanted in the study eye. The mean was lower in the Hydrus group than in the iStent group, and the reported difference was 1.2 mmHg in the iStent-minus-Hydrus direction. Its confidence interval lies above zero, while the unadjusted p-value is 0.033. This describes the observed comparison under the registry’s endpoint definition.

The result does not establish that either device is appropriate for an individual, and it should not be used as medical advice. It does not show what pressure would have been without cataract surgery, because both groups received that procedure. It also does not establish results for medication-treated pressure, other follow-up times, other glaucoma conditions, or settings outside the listed trial.

The secondary findings concern threshold-based outcomes and have intervals that include no group difference. They neither prove that the groups are equivalent nor negate the primary mean comparison. The endpoints answer related but different questions, and the registry does not report whether secondary tests were adjusted for multiple comparisons.

Interpretation is further limited by missing detail about the original statistical plan, multiplicity, and complete handling of missing endpoint data. The primary endpoint population description is truncated, and the reason for the different endpoint and safety denominators is not reported. The posted results therefore support a focused reading of the Month 12 measured outcomes, not a comprehensive conclusion about every relevant outcome or the overall comparative performance of the devices.

17. Why This Trial Matters Statistically

This trial illustrates why the endpoint definition matters in a randomized device comparison. A mean of repeated diurnal pressure measurements uses the measured values across scheduled times, while threshold-based secondary outcomes classify participants according to a response rule. Both approaches can be useful, but they answer different statistical questions. Similar threshold percentages can coexist with a difference in group means without contradiction.

It also shows why effect estimates and their uncertainty should be read together. The primary point estimate gives the direction and scale of the observed mean contrast; the confidence interval indicates the range of values compatible with the data under the reported method. A p-value alone does not communicate the magnitude or precision of the comparison, and it does not establish clinical importance.

The distinction between observed results and planning illustrations is another important lesson. A sample-size calculation based on an observed effect is not evidence of observed power, nor does it reveal the assumptions used to design the completed study. The registry record reports planning assumptions for its illustrations but not the original design assumptions.

Finally, the record highlights the importance of transparency around analysis populations, missing data, and multiplicity. These details determine how the numerical results should be interpreted, especially when multiple outcomes are posted. Clear reporting of those methods is necessary for readers to judge the robustness and intended role of each result.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record does not report the original statistical analysis plan, the sample-size justification for the completed trial, or whether interim analyses were planned or conducted. It also does not identify who was masked in this single-masked study. Those omissions limit assessment of the trial’s prespecified analysis choices and safeguards against bias.

The primary population description is truncated. Although it refers to intent-to-treat participants with verifiable data at the visit and describes special handling for certain cases in response metrics and change in DIOP, the full definition is unavailable. Complete missing-data methods and sensitivity analyses are not reported. The registry also does not explain why the safety at-risk denominators differ from the primary endpoint group sizes.

The primary endpoint is limited to Month 12, with pressure measured at 8 am, 12 pm, and 4 pm after a wash-out from glaucoma medications. The record does not supply results for other time points or medication-treated pressure. Generalization beyond the listed glaucoma conditions and cataract-surgery context is not established by these results.

The secondary endpoints use thresholds and their reported comparisons are unadjusted. No multiplicity strategy or equivalence margin is reported. Safety information is given as counts and selected terms, without fuller context on event timing, duration, or attribution methods. These gaps mean that the posted outcome summaries cannot answer every question about long-term outcomes, robustness to missing data, or comparative safety.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Comparing Hydrus Microstent(TM) to the iStent for Lowering IOP in Glaucoma Patients Undergoing Cataract Surgery — NCT02024464.
• Registry record last updated 2024-07-03; status last verified 2024-06.
• Results first posted 2024-06-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

NCT02024464 is a completed, prospective, multicenter, randomized, parallel-group, single-masked comparison of Hydrus Microstent and iStent in participants undergoing cataract surgery. Each arm combined cataract removal and intraocular lens implantation with insertion of its assigned device in one study eye. Enrollment is listed as 306.

The primary endpoint was mean unmedicated diurnal intraocular pressure at Month 12, measured at three times of day after wash-out from glaucoma medications. The posted mean difference was 1.2 mmHg in the iStent-minus-Hydrus direction. Two secondary pressure-response outcomes are also posted. The registry record does not report the original statistical plan, full missing-data methods, or multiplicity handling, so the results are best interpreted as comparisons tied to the stated endpoint definitions and posted populations.