Study of OMNI Surgical System and iStent for Eyes With OAG (Trident): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of OMNI Surgical System and iStent for Eyes With OAG (Trident) (NCT04658095), a randomized na study. The primary outcome is Mean Change in Unmedicated DIOP From Baseline at the 12-month Postoperative Examination.

2. Clinical Question

The study also described two comparisons of safety and effectiveness: OMNI canaloplasty with trabeculotomy versus iStent inject, and OMNI canaloplasty alone versus iStent inject. These are the comparisons identified in the study summary, but the registry record does not provide outcome estimates or analyses for them. The primary endpoint was intended to assess pressure change after an appropriate washout of glaucoma medications, rather than change while participants continued medication. Because the endpoint was not reached by any subjects before termination, the record cannot answer whether the procedures differed on the planned 12-month measure. It also does not establish how any observed safety counts compare statistically across groups.

3. Trial Design

TRIDENT, registered as NCT04658095, was a prospective, randomized, multicenter, parallel-group study. The registry lists no masking. It enrolled 10 participants and is marked terminated. The listed study start was 2022-01-11, and the primary completion date was 2022-11-18. The phase is recorded as NA.

The three intervention groups were OMNI canaloplasty alone, OMNI canaloplasty plus trabeculotomy, and iStent inject. The OMNI canaloplasty-alone description specifies a procedure up to 360 degrees. The combined OMNI procedure is described as sequential canaloplasty and trabeculotomy, each up to 360 degrees. The iStent group is described as receiving two microstents. All procedures were intended for pseudophakic eyes with open-angle glaucoma.

Although the study was randomized, the registry record does not report how the random sequence was generated, how allocation was concealed, or the intended allocation ratio. It also does not report whether the groups were stratified or whether any covariate adjustment was planned. The absence of masking is recorded, but the record does not explain which individuals were unmasked or whether outcome assessment used any safeguards against knowledge of treatment assignment.

The registry record identifies a single primary outcome measure: mean change in unmedicated DIOP from baseline at the 12-month postoperative examination. No subjects had reached that endpoint when the study terminated. There are no posted analyses for the primary endpoint, and the record does not state why the trial terminated or whether termination was connected to enrollment, conduct, or other circumstances.

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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Results are not presented for this outcome as no subjects had reached the primary endpoint of Month 12 at the time of study termination.

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: The safety analysis population will contain all subjects for whom either the OMNI (canaloplasty alone), OMNI (canaloplasty AND trabeculotomy), or iStent inject is attempted. The study was terminated early due to a business decision.

6. Primary Endpoint

The registry lists the primary outcome as Mean Change in Unmedicated DIOP From Baseline at the 12-month Postoperative Examination, measured over 12 months.

The primary endpoint was mean change in unmedicated DIOP from baseline at the 12-month postoperative examination. The registry defines the change as the mean of the difference between each subject’s baseline DIOP and Month 12 DIOP. Both measurements were to be made after an appropriate washout of glaucoma medications. The registry does not expand the acronym DIOP.

This endpoint was selected to describe pressure change under the specified unmedicated measurement conditions. Measuring after medication washout is intended to distinguish the pressure measurement from the immediate influence of glaucoma medications; that is a general statistical and measurement rationale, not a result reported for this trial. A group mean can summarize the average change, but by itself does not show how variable individual changes were or how precisely the group mean was estimated. Those questions ordinarily require measures of variability and uncertainty, such as a standard deviation and confidence interval.

No endpoint value, group estimate, variability measure, confidence interval, or inferential test is reported. The registry states that no subjects had reached the Month 12 endpoint when the study terminated. Therefore, the planned mean change cannot be described from the posted record, and no comparison of the groups on this outcome can be interpreted.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods describe how trial outcomes are summarized and compared, and how uncertainty is represented. The registry record identifies the primary outcome and broad design features, but it does not report the statistical analysis plan or completed primary-outcome analyses. The concepts below are general explanations, not descriptions of methods confirmed to have been used in this trial.

What does the primary mean represent?

A mean change combines individual participants’ changes into a group-level average. It can make the direction and typical magnitude of change easier to communicate, but it compresses the underlying data. Participants may have changes that differ substantially from the mean. A standard deviation describes spread among individual measurements, while a standard error describes the precision of an estimated mean under a statistical model. A confidence interval uses an estimate and its uncertainty to give a range of values compatible with the data and the method’s assumptions. None of these endpoint summaries is reported for this trial because no subjects reached the primary endpoint before termination.

The registry defines each participant’s change using baseline and Month 12 DIOP after medication washout. A comparison of group means would ordinarily need to specify the exact contrast, the analysis population, and the statistical method. For example, an analysis might compare mean change between groups or model the Month 12 measure while accounting for baseline. These are general possibilities only. The registry record does not report which approach was planned, and no such comparison is posted.

What does randomization contribute?

Random assignment is generally used to make treatment groups comparable in expectation, so differences in outcomes can be interpreted as treatment-group differences more credibly than in a nonrandomized comparison. Randomization does not eliminate chance imbalance, particularly when enrollment is limited. It also does not address problems caused by missing outcome data unless those data are handled appropriately. The record says the study was randomized, but does not report the sequence-generation method, concealment procedures, or allocation ratio. No assumptions about those procedures can be made from the registry entry.

Why are confidence intervals and tests useful?

A point estimate alone would not show how precisely a group difference was estimated. A confidence interval conveys uncertainty under the chosen analysis and assumptions. A hypothesis test, often reported with a p-value, evaluates how compatible the observed data are with a specified null hypothesis under a statistical model. Neither a p-value nor a confidence interval measures clinical importance by itself. In this trial, there are no posted primary endpoint estimates, confidence intervals, or p-values to interpret.

When several groups or outcomes are compared, multiple testing can increase the chance of obtaining at least one apparently notable result by chance. General approaches include defining a primary comparison in advance, adjusting for multiple comparisons, or clearly labeling analyses as exploratory. The registry describes more than one safety and effectiveness comparison, but the analysis hierarchy and multiplicity procedure are not reported. There are no posted primary outcome analyses to assess for multiplicity.

How should planning calculations be distinguished from results?

Sample-size calculations are planning tools that estimate the number of participants needed under assumed effect sizes, variability, significance levels, and allocation. They are not observed outcomes and do not show whether a completed analysis would have detected a difference. A planning illustration based on an observed effect is also not the trial’s original sample-size justification. The registry record does not report the trial’s own sample-size justification. The posted record contains no primary endpoint estimate from which to judge the trial’s precision on that endpoint. Planning assumptions cannot replace the missing result, and planned power is not the same as observed power.

General statistical methods also rely on assumptions, such as how outcome measurements vary and whether the model represents that variation adequately. Over-dispersion, in general, occurs when data vary more than a model assumes; if not accommodated, estimated uncertainty can be too small. The registry record does not report a model for this endpoint, a dispersion assessment, or any diagnostic checks. As a result, no model assumptions can be evaluated from the posted outcome information.

For safety counts, descriptive numbers can be reported without a formal comparison. A comparative safety analysis would need to specify event definitions, observation time, and an analysis method; none is reported for the posted counts. The small numbers at risk also mean that the counts provide limited information about uncommon events. This general limitation should not be confused with evidence of a statistically established difference.

10. Multiplicity, Missing Data and Analysis Populations

The registry record identifies the 12-month mean change in unmedicated DIOP as the primary outcome and describes two safety and effectiveness comparisons: combined OMNI canaloplasty and trabeculotomy versus iStent inject, and OMNI canaloplasty alone versus iStent inject. It does not report how these comparisons were ordered, whether one was designated as the primary contrast, or whether an adjustment for multiple comparisons was planned. A multiplicity strategy is not reported in the registry record.

The record says no subjects had reached the primary endpoint at the time of termination. It does not describe whether earlier observations were available, how missing outcome data were to be handled, whether imputation was planned, or whether sensitivity analyses were specified. The reason for termination is not reported. Without those details, it is not possible to assess whether missingness was expected, related to participant characteristics or outcomes, or addressed through a defined analysis.

The analysis populations are also not reported. The registry does not specify whether the intended primary analysis was based on all randomized participants, participants who received an assigned procedure, or participants meeting other criteria. Group-specific assignment and follow-up counts for the primary outcome are absent. Consequently, the enrolled total cannot be interpreted as an analyzed sample.

These omissions do not imply that the study team did or did not use particular procedures; they mean that the registry record does not document them. Since the primary outcome is unavailable, there is no posted analysis from which to evaluate multiplicity control, missing-data assumptions, or consistency across analysis populations.

11. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse event counts separately for the three intervention groups. OMNI-canaloplasty Alone lists 5 participants at risk and 0 with a serious adverse event. OMNI-canaloplasty + Trabeculotomy lists 1 at risk and 0 with a serious adverse event. iStent Inject lists 4 at risk and 0 with a serious adverse event. The record lists 0 deaths in each group.

For other adverse events, the corresponding counts affected are 3 of 5 in OMNI-canaloplasty Alone, 1 of 1 in OMNI-canaloplasty + Trabeculotomy, and 0 of 4 in iStent Inject. These are posted descriptive counts, not adjusted comparisons. The registry does not provide event terms for the serious adverse events, and the serious-event term list is empty. It does not report event timing, duration, severity grading beyond the serious classification, or an inferential safety analysis.

Counts should be read with their group sizes in mind. A zero recorded serious-event count in these groups does not establish that the risk is absent. Nor do the other-event counts establish a comparative difference between procedures. The record does not report the reason for termination or whether adverse-event reporting was complete at termination.

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

The posted record establishes that TRIDENT was a randomized, parallel-group study of three procedures in pseudophakic eyes with open-angle glaucoma, and that it terminated after enrolling 10 participants. It also establishes that no subjects had reached the primary endpoint of Month 12 when the study terminated. These registry entries describe the trial’s status and the absence of its planned primary outcome, rather than the comparative effects of the procedures.

The primary question concerned mean change in unmedicated DIOP from baseline after medication washout. Since no endpoint results are presented, the record does not show the average change in any group, the size or direction of differences between groups, or the precision of any such difference. It does not show whether an apparent difference would be compatible with chance variation or whether it would be clinically important.

The safety counts describe the events recorded among the participants at risk in each group. They do not answer the primary effectiveness question. They also do not support a definitive ranking of the procedures for safety: the group counts are limited, the registry provides no comparative safety analysis, and detailed event terms and timing are not reported.

In general, an unreported result is not evidence that groups had equal outcomes, and a missing endpoint is not evidence of no effect. Likewise, zero serious adverse events in the listed groups should not be interpreted as proof of no serious-event risk. The reason for termination and the intended handling of incomplete follow-up are not reported, so the available record cannot explain why the endpoint was unavailable or how representative the posted safety counts are of the intended study follow-up.

The appropriate statistical conclusion is therefore narrow: the registry documents the study design, enrollment, termination, and posted safety counts, but supplies no analyzable primary endpoint comparison. It cannot establish comparative effectiveness or a definitive comparative safety result.

13. Why This Trial Matters Statistically

This trial illustrates an important distinction between a randomized design and an interpretable randomized comparison. Randomization is a method for supporting a fair comparison, but a comparison still requires outcome data. When the planned primary endpoint is not reached, the design alone cannot estimate a group difference or its uncertainty. Here, the registry says that no subjects reached the Month 12 endpoint before termination, so the central efficacy question remains unanswered in the posted record.

The record also shows why enrollment and analysis counts must not be treated as interchangeable. It lists 10 enrolled participants, while reporting no subjects at the primary endpoint. Without group-specific follow-up and analysis counts, readers cannot infer how many participants could contribute to other outcomes or whether the posted safety counts represent complete follow-up.

Safety reporting raises a related issue. Event counts are useful descriptive information, but small numbers and uneven group counts do not provide a stable basis for a comparative claim. A zero count is informative as a report of what was recorded, but does not imply that the underlying possibility of an event is zero.

Finally, a terminated study is not automatically a failed or successful test of a treatment. The reason for termination is not reported, and the record contains no primary result with which to evaluate the stated question. Statistically, the key lesson is that design intentions, enrollment, and observed endpoints are distinct: only the latter can directly support the planned outcome comparison. The registry record permits a clear account of what was planned and what was posted, while leaving the main comparative outcome unresolved.

14. 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 most consequential limitation is that the primary endpoint is not reported because no subjects reached the 12-month postoperative examination before termination. Without baseline-to-Month 12 group summaries, the primary comparison cannot be estimated or interpreted. There are no posted confidence intervals, variability measures, or statistical tests for that outcome.

Enrollment was 10, and the registry does not report group-specific assignment totals or primary-outcome analysis populations. The record therefore does not show how participants were distributed among the three groups, how many had follow-up before termination, or whether all enrolled participants were included in the safety summaries. The reason for termination is also not reported.

Design details that could affect assessment of bias are absent: the method of random sequence generation, allocation concealment, the intended allocation ratio, and the roles of individuals who were unmasked are not described. The record does not report the statistical analysis plan, the sample-size justification, the approach to missing data, or a multiplicity strategy.

The safety data are limited to group counts. Serious adverse event terms, timing, duration, and a comparative analysis are not presented. The registry lists other adverse events, but the posted counts alone do not explain their nature or clinical course. These limitations restrict interpretation of both safety and effectiveness. They are limitations of the information reported in the registry record and do not establish what procedures may have been used outside that record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of OMNI Surgical System and iStent for Eyes With OAG (Trident) — NCT04658095.
• Registry record last updated 2025-10-27; status last verified 2025-09.
• Results first posted 2025-10-27.
• 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.

18. Record Summary

NCT04658095, titled “Study of OMNI Surgical System and iStent for Eyes With OAG (Trident),” is a prospective, randomized, multicenter, parallel-group study sponsored by Sight Sciences, Inc. The official title describes a comparison of OMNI Surgical System procedures and iStent inject in pseudophakic eyes with open-angle glaucoma. The registry lists 10 enrolled participants, no masking, and terminated status. The listed start date is 2022-01-11, and the primary completion date is 2022-11-18.

The primary outcome was mean change in unmedicated DIOP from baseline at the 12-month postoperative examination. The registry states that no subjects had reached this endpoint when the study terminated, and no primary outcome analyses are posted. Safety counts are reported by intervention group, including zero serious adverse events and zero deaths in each group. The reason for termination, detailed analysis methods, and the trial’s sample-size justification are not reported in the registry record.