A Post-market Study Of Use Of The OMNI® Surgical System In Open Angle Glaucoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Post-market Study Of Use Of The OMNI® Surgical System In Open Angle Glaucoma (NCT04616573), a randomized na study. The primary outcome is Change in Unmedicated Diurnal Intraocular Pressure (DIOP).

2. Clinical Question

The registry record describes a prospective, randomized, parallel study of surgical device procedures in people with open-angle glaucoma. Its official title frames the study as comparing use of the OMNI Surgical System in combination with cataract extraction. The record lists three treatment arms, but only one had a participant treated.

The brief summary says the study was intended to prospectively compare the clinical effect of the OMNI system in eyes with open-angle glaucoma. However, the posted record says the trial ended early after randomization and treatment of one subject, who exited after 1 week of follow-up. It explicitly states that no meaningful conclusions or results were obtained. The clinical question can therefore be described from the planned arms and outcome, but the study did not generate the comparative evidence that question would require.

3. Trial Design

This was a post-market study with randomized allocation and a parallel design. Three arms are listed: OMNI with trabeculotomy, OMNI without the listed trabeculotomy component, and iStent Inject implantation. The registry record reports enrollment of 1. One participant was treated in the OMNI-with-trabeculotomy arm; the other two arms had no treated participants.

The official title describes the study as masked, while the registry’s masking classification is “NONE.” The record therefore contains differing descriptions of masking, and further details that might clarify the discrepancy are not reported in the registry record. The randomization method, allocation concealment, and any procedures for maintaining masking are also not reported in the registry record.

The record lists a start date of 2020-11-13 and a primary completion date of 2021-01-20, and gives the study status as terminated. Its primary outcome was change in unmedicated diurnal intraocular pressure (DIOP), with a timeframe of 1 week. Four secondary outcomes are listed: eyes with a decrease of at least 20% in unmedicated mean DIOP from baseline; eyes with unmedicated DIOP between 6 and 18 mmHg inclusive; change in the number of ocular hypotensive medications compared with screening; and change in unmedicated DIOP from baseline.

The record says termination occurred early after one subject was randomized and treated, and that the subject exited after 1 week of follow-up. Reasons for termination beyond this description, any planned recruitment target, and details of the study’s intended analysis are not reported in the registry record. Given the very limited enrollment and empty arms, the posted data describe an incomplete study rather than a completed comparison across the listed treatments.

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

Analysis population for the primary outcome, as defined in the registry: No subjects were analyzed is for the 2 arms that did not have any subjects treated in the study.

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: Only one subject was treated in the study. Study terminated early. No data to report for the other arms

6. Primary Endpoint

The registry lists the primary outcome as Change in Unmedicated Diurnal Intraocular Pressure (DIOP), measured over 1 week.

The primary endpoint is change in unmedicated diurnal intraocular pressure (DIOP), reported in mmHg, with a stated timeframe of 1 week. The endpoint concerns pressure measured across the day without medication, and the registry record identifies the change as being from baseline. The posted record does not describe the measurement schedule, how the diurnal value was summarized, or how baseline was defined.

As a general statistical concept, a change-from-baseline endpoint compares a participant’s later measurement with that participant’s baseline measurement. Such an endpoint can describe the direction and size of change over the specified follow-up, but interpretation depends on clear measurement definitions and sufficient observations. Here, the registry lists a value of 13.3 mmHg for the only arm with a treated participant. It does not post a measure of spread or a confidence interval, and there are no treated participants in the other arms. The value therefore cannot be used to estimate a between-arm difference or the uncertainty around one.

The endpoint is clinically relevant to the stated study question because the registry’s brief summary identifies comparison of clinical effect in open-angle glaucoma, and several listed outcomes also concern DIOP or medication use. That explains the role of the measure in the trial, but does not make this record a reliable estimate of treatment effect. The registry explicitly states that no meaningful conclusions or results were obtained following early termination.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The posted results are descriptive rather than a usable comparative analysis. The trial has a randomized, parallel structure in the registry, but random assignment alone cannot produce a meaningful treatment comparison when nearly all listed arms have no treated participants. The one populated arm has one participant; the other arms have zero. Thus, there is no observed outcome distribution for comparing the procedures.

What a group summary can show

In general, a group summary describes the observations recorded in a treatment arm. With one participant, a posted value can report that individual’s recorded result, but it cannot describe between-participant variation. A measure of spread, such as a standard deviation, requires information about variation among observations. The registry gives no spread value for the primary outcome. This absence is especially consequential because there is only one observation in the populated arm.

The primary outcome is described as change in unmedicated DIOP, and the posted value is 13.3 mmHg. A change measure ordinarily depends on a baseline and a follow-up measurement, but the underlying values and calculation details are not reported in the registry record. The result should therefore be read as the registry’s posted summary, not reconstructed from unreported measurements.

Why an interval estimate is unavailable

In general, a confidence interval describes a range of values compatible with the data and the method used to calculate the interval. Its width reflects both the amount of information and the variability in the observations. Here, no interval is posted, and the available data do not provide a basis for a useful comparative interval. There is no outcome information from two of the three arms, and the single observation in the remaining arm cannot estimate the variability among participants. An interval would not solve the problem of absent comparison-arm results.

Likewise, a p-value would address a defined statistical comparison under a specified analysis. The registry reports zero analyses, and no p-value or comparative test result is posted. The statistical plan, including any model, covariate adjustment, or hypothesis-testing procedure, is not reported in the registry record. It would be inappropriate to infer those choices from the trial’s randomized design or its outcome list.

Randomization and treatment comparisons

As a general concept, randomization is intended to make treatment groups comparable on average by assigning participants through a chance-based process. It does not ensure that groups are balanced in a very small study, and it cannot create information for arms with no participants. The registry identifies the study as randomized, but the method used to generate or implement assignments is not reported in the registry record. The available results do not allow an assessment of baseline balance or the consequences of randomization.

The study is listed as parallel, meaning the registry describes separate arms rather than a crossover arrangement. The official title says “masked,” but the masking classification is “NONE.” The methods used to mask participants, clinicians, outcome assessors, or analysts are not reported in the registry record. The two descriptions should not be reconciled by assumption.

Planning illustrations are not observed power

General sample-size planning asks how many participants might be needed to detect a specified effect under chosen statistical assumptions. The planning framework describes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it also describes effects as fractions of an observed effect. These are planning assumptions, not evidence that the trial used them. The registry’s own design assumptions and sample-size justification are not reported in the registry record.

In this case, the posted data do not yield an estimable two-arm effect for the listed treatment comparisons. The page therefore notes that values are missing or not estimable for a two-arm comparison. Any sample-size illustration must be read as a planning exercise, where available, and never as observed power or as a recommendation based on a dependable treatment effect. A single participant’s result is too limited to support a stable estimate of the effect that a future study might need to detect.

Multiplicity and analysis choices

Multiplicity arises in general when a study evaluates several outcomes or several comparisons, because repeated testing can increase the chance of at least one apparently notable result. The registry lists one primary outcome and four secondary outcomes, but it does not report an adjustment strategy or a hierarchy among secondary outcomes. More importantly, no analyses are posted. There are no reported test results for which multiplicity adjustment can be assessed.

The record’s limited enrollment, absent comparison-arm outcomes, and lack of posted analysis details constrain interpretation before questions about the exact statistical method arise. The appropriate reading is that the registry records an early-terminated randomized study with sparse descriptive results, not a completed efficacy analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and four secondary outcomes. The secondary outcomes concern a decrease in unmedicated mean DIOP, a DIOP range, change in ocular hypotensive medication count, and change in unmedicated DIOP from baseline. Listing these outcomes does not establish that they were measured or analyzed. The record reports zero analyses and does not post results for the secondary outcomes.

In general, multiplicity is a concern when several outcomes or comparisons are tested, since a larger set of tests can increase the chance of a seemingly notable result by chance. The registry’s approach to multiplicity, including any adjustment or outcome hierarchy, is not reported in the registry record. Because no analyses are posted, there is no set of reported tests from which to assess whether multiplicity affected conclusions.

The record states that one subject was treated and exited after 1 week of follow-up. It also states that the two arms without treated subjects had no subjects analyzed. Further details about the subject’s available measurements, any missing measurements, or how missing data were handled are not reported in the registry record. The analysis population, including whether the study planned an intention-to-treat or another approach, is not reported in the registry record.

These gaps matter because an analysis depends on which participants and measurements are included. Here, the available information is too limited to assess the impact of missing data or to define a comparative analysis population. No imputation, sensitivity analysis, or other missing-data procedure is reported in the registry record. The early termination and absent arms are fundamental limitations, not issues that can be resolved by assuming an analysis method.

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

For the OMNI-with-trabeculotomy arm, the registry lists one participant at risk for serious adverse events and zero serious adverse events. It lists one participant at risk for other adverse events and one other adverse event. The death count is zero. The two other arms each list zero participants at risk and zero events.

These counts should be read as sparse descriptive safety information. The one other event is a count, not an estimate of how often such events would occur in a larger group. The record does not provide the event term, timing, severity, relationship to the procedure, or outcome. It also does not establish that the event was caused by the intervention. No serious events or deaths are listed for the single participant, but that observation cannot establish the absence of risk in a broader population.

For arms with zero participants at risk, zero reported events do not provide a meaningful safety comparison. There were no treated participants in those arms from whom to observe events. The registry’s event counts therefore cannot support comparative safety conclusions across the listed procedures.

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

This record shows that a randomized post-market study was registered with three listed treatment arms and outcomes centered on unmedicated DIOP and medication use. It also shows that enrollment was 1, the study was terminated, and only the OMNI-with-trabeculotomy arm had a treated participant. The primary outcome listing contains a value of 13.3 mmHg, while the registry says no meaningful conclusions or results were obtained because the study ended early after treatment of one subject.

The posted data do not show whether one procedure is better or worse than another. There are no treated participants in the other arms, no comparative analysis, and no estimate of uncertainty around the single posted primary-outcome value. The value does not establish a typical response or support a conclusion about the effect of treatment in people with open-angle glaucoma. The record also does not establish how the reported change was calculated from baseline.

The record does not answer whether the listed interventions differ in safety. It reports no serious adverse events and no deaths for the single participant in the populated arm, along with one other adverse event. It gives no event details and has no participants at risk in the other arms. These observations are too limited for a comparative safety conclusion.

Nor does the record establish why the trial was terminated, why the participant exited, or how the study’s results would have been analyzed had more participants been enrolled. Those details are not reported in the registry record. The appropriate interpretation is narrow: the registry documents an early-terminated study with one treated participant and insufficient posted evidence for meaningful efficacy or comparative safety conclusions.

The record can still clarify what the investigators intended to study: treatment procedures involving OMNI and iStent, in a population with open-angle glaucoma, with change in unmedicated DIOP as the primary outcome. It cannot answer that intended comparative question from the available results.

13. Why This Trial Matters Statistically

This study is statistically instructive because it illustrates the difference between a trial’s planned question and the evidence its posted results can answer. Randomization and a defined primary outcome are important design features, but they do not compensate for having only one treated participant and no treated participants in two of the listed arms. A randomized label is not, by itself, evidence of a reliable comparison.

The record also shows why a single numerical result should not be read in isolation. The primary outcome value of 13.3 mmHg has no posted dispersion measure or confidence interval, and the record does not provide a comparative estimate. Without information about variation and without results from comparison arms, the value cannot show how consistent outcomes might be or how the procedures compare.

The outcome list gives a further lesson: registered outcomes are not the same as analyzed outcomes. Four secondary outcomes appear in the record, but no secondary results or analyses are posted. The existence of an outcome in a registry does not show that it was measured, analyzed, or interpreted.

Finally, the study’s early termination sharply limits both clinical and statistical interpretation. The registry explicitly states that no meaningful conclusions or results were obtained. This is a case where transparent reporting of limited data is important: readers can distinguish the intended comparison from the evidence actually available, and avoid treating a single participant’s result as a group-level estimate.

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 important limitation is the extremely small enrollment. The record reports one treated participant, assigned to the OMNI-with-trabeculotomy arm, while the other two arms had no treated participants. This prevents meaningful comparisons across the listed procedures and leaves no basis for estimating between-participant variability.

The trial was terminated early, and the single subject exited after 1 week of follow-up. The registry states that no meaningful conclusions or results were obtained. The reason for termination and the reason for the subject’s exit are not reported in the registry record. The primary outcome timeframe is 1 week, so the record also does not provide evidence about outcomes beyond that stated timeframe.

The primary result is posted as 13.3 mmHg, but the registry provides no spread measure or confidence interval. The baseline measurement and the method used to calculate the reported change are not described. There are no posted secondary outcome results, although four secondary outcomes are listed, and the record reports zero analyses.

Important design and analysis details are not reported in the registry record, including the randomization procedure, allocation concealment, statistical analysis plan, analysis population, and handling of missing data. The official title describes masking, whereas the masking classification is “NONE”; the record does not explain this difference. The limited safety counts also lack details about the one other adverse event. Together, these limitations mean that the posted results should be treated as an incomplete descriptive record, not as a comparative estimate of efficacy or safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Post-market Study Of Use Of The OMNI® Surgical System In Open Angle Glaucoma — NCT04616573.
• Registry record last updated 2022-12-01; status last verified 2022-11.
• Results first posted 2022-12-01.
• 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

NCT04616573 is a randomized, parallel post-market study of device procedures in open-angle glaucoma. Its official title describes use of the OMNI Surgical System in combination with cataract extraction. The registry lists three arms: OMNI with trabeculotomy, OMNI without the listed trabeculotomy component, and iStent Inject implantation.

The study enrolled 1 and is listed as terminated. One participant was treated in the OMNI-with-trabeculotomy arm; the other arms had no treated participants. The primary outcome was change in unmedicated DIOP at 1 week, with a posted value of 13.3 mmHg for the populated arm. The record states that early termination after treatment of one subject meant no meaningful conclusions or results were obtained.

Four secondary outcomes are listed, but no analyses or secondary results are posted. The safety listing includes zero serious adverse events and zero deaths among one participant at risk in the populated arm, with one other adverse event. The registry’s masking classification is “NONE,” although its official title uses the word “Masked.”