This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Post Market Study of the InnFocus MicroShunt (NCT02177123), a na na study. The primary outcome is Number of Participants With Study Success.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02177123 |
| Phase | NA |
| Condition | Primary Open Angle Glaucoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 107 |
| Arms in the primary outcome | n/a |
| Lead sponsor | InnFocus Inc. |
| Results posted | Yes |
2. Clinical Question
Population
People with primary open-angle glaucoma who signed informed consent and received the InnFocus MicroShunt under evaluation. The registry describes the primary endpoint population as the intent-to-treat population. The study enrolled 107 participants.
Intervention
InnFocus MicroShunt implantation in the anterior chamber of the eye, following an antiproliferative treatment with mitomycin C.
Comparator
There was no separate control group. This was a single-group study, and the registry does not report a randomized comparison.
Primary question
How many participants met the study’s definition of success with respect to intraocular pressure at Month 6, 9, 12 and 24? The registry describes the outcome but does not report the numerical success results or the threshold used to define success.
The study was a prospective, multicentric, single-arm post-market study of the CE Marked InnFocus MicroShunt, also identified as the MIDI Arrow. Its stated purpose was to gather safety and effectiveness data in people with primary open-angle glaucoma. The primary endpoint counts participants classified as successful at specified follow-up points. A count can describe how many participants met a criterion in this study, but without a concurrent comparison group it cannot establish how the outcome would have differed under another treatment or under no implantation.
The registry also lists intraocular pressure change as a secondary outcome. The numerical results for that outcome are not reported in the registry record. The primary endpoint’s definition, including any required pressure level, reduction, medication condition, or other component, is also not reported. Therefore, the clinical question is visible, but the record does not supply enough endpoint detail to determine exactly how success was classified or how often it occurred.
3. Trial Design
This was a completed, prospective, multicentric, single-group post-market study. The registry records enrollment of 107 participants and identifies InnFocus Inc. as the sponsor. The study start date was 2014-04-04, and the primary completion date was 2017-11-27. The registry lists phase as not applicable, allocation as not applicable, and masking as none. These entries are consistent with the single-group design, rather than a masked randomized comparison.
Participants received implantation of the InnFocus MicroShunt in the anterior chamber of the eye after an antiproliferative treatment with mitomycin C. The registry describes the device as CE Marked and identifies it as the MIDI Arrow. No separate comparator arm is described. The study record does not report a control group, so the results cannot be interpreted as a direct estimate of the difference between the device and another treatment.
The primary endpoint is the number of participants with study success with respect to intraocular pressure at Month 6, 9, 12 and 24. Its stated population is the intent-to-treat population, described in the record as people who signed informed consent and received the assigned therapy under evaluation. That definition is the record’s wording; further details about eligibility, follow-up, or handling of participants without endpoint data are not reported in the registry record.
The registry lists three outcome measures and identifies intraocular pressure change as a secondary outcome. It records no posted analyses. Numerical primary endpoint results, numerical results for the secondary outcome, and the study’s statistical analysis plan are not reported in the registry record. The completed status indicates the registry’s administrative status, but does not by itself provide evidence about the completeness or precision of the posted outcome data.
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
| Stage | Subjects Suffering From Primary Open Angle Glaucoma |
|---|---|
| STARTED | 107 |
| COMPLETED | 83 |
| NOT COMPLETED | 24 |
Reasons for not completing this period:
| Reason | Subjects Suffering From Primary Open Angle Glaucoma |
|---|---|
| Lost to Follow-up | 6 |
| Withdrawal by Subject | 4 |
| Adverse Event | 4 |
| Physician Decision | 3 |
| Excluded by Sponsor - other reason | 2 |
| Excluded for medical reasons | 2 |
| Death | 1 |
| Other | 1 |
| Excl. #31 Ocular pathology or medical condition which would place subject at increased risk | 1 |
Analysis population for the primary outcome, as defined in the registry: The Intent-to-Treat (ITT) population included all patients who have signed the informed consent and received the assigned therapy under evaluation (InnFocus MicroShunt).
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 Intent-to-Treat (ITT) population included all patients who have signed the informed consent and received the assigned therapy under evaluation (InnFocus MicroShunt).
| Characteristic | Unit | Subjects Suffering From Primary Open Angle Glaucoma |
|---|---|---|
| Participants analysed | 101 | |
| Age, Continuous | years | 63.7 (SD 12.6) |
| Sex: Female, Male: Female | Participants | 53 |
| Sex: Female, Male: Male | Participants | 48 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: France | Participants | 65 |
| Region of Enrollment: Switzerland | Participants | 8 |
| Region of Enrollment: Netherlands | Participants | 12 |
| Region of Enrollment: Spain | Participants | 16 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Study Success, measured over Month 6, 9, 12, and 24.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants classified as having study success with respect to intraocular pressure at Month 6, 9, 12 and 24. The registry says that the assessment uses the intent-to-treat population and describes that population as participants who signed informed consent and received the assigned therapy under evaluation. The endpoint is therefore a participant count at specified follow-up times, rather than a continuous summary of pressure change.
In general, a binary success endpoint can make a study result easier to interpret as the proportion of participants meeting a prespecified criterion. It depends, however, on a clear definition of success and consistent ascertainment at each time point. Here, the registry record does not report the threshold or full rules used to classify success. It also does not report the numerical counts or rates at the listed follow-up times. The endpoint title and description alone cannot establish whether success required a particular pressure level, a specified change from baseline, medication status, or other conditions.
The registry lists intraocular pressure change as a secondary outcome, but does not report its numerical results in the record. Such a continuous measure could describe the direction and size of change, while the binary endpoint classifies participants against a criterion. These outcomes answer related but distinct questions. Without the success definition and results, the primary endpoint cannot be independently interpreted or compared with another study’s endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies the study as a single-arm investigation with 107 enrolled participants. Its primary endpoint concerns the number of participants meeting a study-success criterion with respect to intraocular pressure at Month 6, 9, 12 and 24. However, the numerical results for this endpoint are not reported in the registry record. The record also does not report the success criterion itself. Consequently, it does not support a numerical account of how often success occurred, how that count changed across follow-up, or how precisely any estimate was measured.
A single-group result is descriptive of the participants observed in that group. It does not directly estimate a treatment contrast, because there is no separate control arm in the registry record. Changes over time may be relevant to describing participants’ outcomes, but without a concurrent comparison they cannot distinguish the effect of implantation from other influences, including the natural course of disease, changes in care, or differences in follow-up. Those are general interpretive considerations, not findings established by this registry entry.
The listed primary endpoint is a count of participants with study success, while the secondary outcome is intraocular pressure change. The record does not provide numerical results for either outcome. It also records no analyses. The tables and plots elsewhere on the page should be read as displays of whatever results they contain, not as a substitute for missing endpoint definitions or a comparison group. In particular, a visual pattern cannot establish a causal treatment effect where the design has no control arm.
The sample-size section is a planning illustration, not an observed-power analysis or a report of the study’s original design rationale. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is expressed as a fraction of the observed effect. The registry record does not report that these assumptions were used to plan this single-group study. Any displayed sample-size figures should therefore be interpreted as hypothetical planning quantities under the stated assumptions, not as evidence that the trial was adequately powered or that a particular effect was detected.
The adverse-event summary reports 11 affected participants among 107 at risk for serious adverse events, 67 affected participants among 107 at risk for other adverse events, and 1 death. These are descriptive safety figures. The record does not report event-level timing, the relationship of events to the device or procedure, or further detail that would establish causality. The serious-event terms and percentages listed in the safety section add context, but they do not replace a full accounting of event definitions and participant follow-up.
Overall, the registry describes the study question, design, endpoint timing, and selected safety summaries. It does not report enough primary outcome information to quantify endpoint success or assess its precision. The single-group design also limits comparative interpretation, regardless of whether outcome values are shown elsewhere.
9. Statistical Methods Explained
This discussion distinguishes the study’s design from the general statistical ideas used to interpret its endpoints and the planning illustration. The registry describes a single-group study, a participant-count primary endpoint, follow-up at Month 6, 9, 12 and 24, and an intent-to-treat population. It does not report a statistical analysis plan or posted analyses.
What does a single-group design estimate?
In general, a single-group study can describe outcomes among participants who receive the intervention under evaluation. For a binary endpoint such as study success, the central descriptive quantity is the number or proportion meeting the stated criterion. A confidence interval, when reported, expresses statistical uncertainty around an estimate under the assumptions of the method used. It is not a guarantee that the true value lies within a particular range, and it does not address systematic biases or missing information.
Because the registry describes no control group, this design does not directly estimate a contrast between the MicroShunt and another treatment. A within-group description and a randomized between-group comparison answer different questions. In general, causal comparisons rely on a design and analysis that make the groups comparable. The record’s single-group design does not provide such a concurrent comparison.
What does the binary endpoint require?
The primary endpoint counts participants with study success at specified follow-up points. To interpret a binary endpoint, the criterion for success needs to be explicit, including how borderline or unavailable measurements are handled. The registry describes success with respect to intraocular pressure but does not report the threshold or complete classification rules. It also does not report the numerical success counts in the registry record.
In general, a proportion can be more directly understandable than a pressure measurement, but turning a continuous outcome into success or not-success discards information about how far participants are from the threshold. The choice of threshold can materially shape the number classified as successful. Without the stated criterion, readers cannot assess that choice or compare it reliably with definitions used elsewhere.
How should repeated follow-up points be read?
The endpoint is assessed at Month 6, 9, 12 and 24. In general, repeated assessments can show how outcomes are described at different times, but each time point may have a different amount of available information. Interpretation depends on whether the same participants contribute measurements at each point and how missing visits or measurements are handled. Those details are not reported in the registry record. The listed time points should not be treated as proof that every enrolled participant was assessed at every visit.
Repeated time points also raise a general issue of multiplicity: examining several outcomes or time points creates several opportunities to identify a result that appears notable by chance. Whether and how an analysis accounts for that issue depends on a prespecified plan. A multiplicity strategy is not reported in the registry record, so no adjustment or hierarchy should be assumed.
What do the planning assumptions mean?
The sample-size section is described as a planning illustration based on the observed effect, rather than the study’s own design. It uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It considers an effect to detect stated as a fraction of the observed effect. For non-time-to-event outcomes, the section reports participants per arm for 80% power or other displayed power targets; for time-to-event outcomes, the stated convention is a total number of events.
These are general planning concepts, not a record of this study’s design: the study itself is single-group. A significance level sets a decision threshold for a test under its assumptions; power is the chance of detecting a specified effect under a model if that effect is true. A planning sample size is not observed power and does not show that an effect was found. It is also not a substitute for a confidence interval around an observed estimate. The registry does not report the study’s own sample-size justification or analysis plan.
Why can event counts need special care?
The primary endpoint is a count of participants classified as successful, not a count of repeated events. In general, counts can arise from different processes: some count distinct people, while others count multiple events per person. Those interpretations require different methods. The registry explicitly describes this endpoint as participants with an event, with counts, but does not report a model or analysis for the primary result. The safety summary separately gives participants affected and should not be read as a complete event-level analysis.
In general, over-dispersion occurs when count data vary more than a chosen model expects. If a count model assumes less variation than the data contain, standard errors may be too small and intervals too narrow. This concept is relevant only when an appropriate count model is being considered; the registry does not report such a model for this study. The record’s lack of posted analyses means readers cannot determine which estimation method, uncertainty measure, or model checks were used.
The tables and plots can help present numerical results, but interpretation still depends on their definitions, denominators, and uncertainty estimates. Where those details are not reported in the registry record, the visual summaries cannot resolve the underlying methodological uncertainty.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint is assessed at Month 6, 9, 12 and 24, and the registry lists intraocular pressure change as a secondary outcome. The record identifies three outcome measures overall, but the complete set of definitions and numerical results is not reported. Examining several outcomes or time points can create a multiplicity issue: in general, the more opportunities an analysis has to identify a result as notable, the greater the chance of a finding arising by chance under a null model. A prespecified outcome hierarchy or adjustment can address this in some settings, but no such plan is reported in the registry record.
The registry states that the primary endpoint population is the intent-to-treat population and defines it as participants who signed informed consent and received the assigned therapy under evaluation. Because this is a single-group study, the phrase “assigned therapy” refers to the intervention under evaluation, not to randomized assignment between study arms. The record does not report how participants with missing follow-up measurements were handled, whether any participants were excluded from a particular time point, or whether missingness was imputed.
In general, missing data matter when the availability of a measurement is related to the outcome or to participant characteristics. A complete-case summary, an imputation method, and a model using partial follow-up can rely on different assumptions. Without a reported method and follow-up accounting, readers cannot judge how missing measurements might affect the endpoint estimates.
The registry records no posted analyses. The statistical analysis plan, methods for multiplicity, missing-data handling, and any sensitivity analyses are not reported in the registry record. These gaps limit independent assessment of how the endpoint was analyzed and how robust any reported estimate may be.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Subjects Suffering From Primary Open Angle Glaucoma | 11 | 107 | 10.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Subjects Suffering From Primary Open Angle Glaucoma | 1 of 107 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Subjects Suffering From Primary Open Angle Glaucoma | 67 of 107 |
Most frequent serious adverse event terms
| Event term | Organ system | Subjects Suffering From Primary Open Angle Glaucoma |
|---|---|---|
| Intraocular Pressure Increased | Investigations | 4 of 107 |
| Allergic Keratitis | Eye disorders | 1 of 107 |
| Anterior Chamber Inflammation | Eye disorders | 1 of 107 |
| Cataract | Eye disorders | 1 of 107 |
| Ulcerative Keratitis | Eye disorders | 1 of 107 |
| Sclerectomy | Surgical and medical procedures | 1 of 107 |
| Trabeculectomy | Surgical and medical procedures | 1 of 107 |
| Implant Site Dehiscence | General disorders | 1 of 107 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Subjects Suffering From Primary Open Angle Glaucoma |
|---|---|---|
| Intraocular Pressure Increased | Investigations | 26 of 107 |
| Hypotony Of Eye | Eye disorders | 10 of 107 |
| Conjunctival Bleb | Eye disorders | 8 of 107 |
| Keratitis | Eye disorders | 8 of 107 |
| Implant Site Dehiscence | General disorders | 6 of 107 |
| Lacrimation Increased | Eye disorders | 5 of 107 |
| Visual Acuity Reduced | Eye disorders | 5 of 107 |
| Cataract | Eye disorders | 4 of 107 |
| Eye Pain | Eye disorders | 4 of 107 |
| Punctate Keratitis | Eye disorders | 4 of 107 |
Serious events with the highest arm-level rate: intraocular pressure increased (3.7%), allergic keratitis (0.9%), anterior chamber inflammation (0.9%), cataract (0.9%), ulcerative keratitis (0.9%).
The safety summary lists 107 participants at risk for serious adverse events, of whom 11 were affected. It also lists 107 at risk for other adverse events, with 67 affected, and reports 1 death. These are counts of participants in the registry summary. They should not be interpreted as the total number of individual events, because one participant may have experienced more than one event. The registry does not provide further event-level detail in the registry record recorded.
The listed serious adverse-event terms are Intraocular Pressure Increased at 3.7%, Allergic Keratitis at 0.9%, Anterior Chamber Inflammation at 0.9%, Cataract at 0.9%, Ulcerative Keratitis at 0.9%, and Sclerectomy at 0.9%. These terms and percentages describe entries in the registry’s serious-event summary; the record does not report their timing, duration, outcome, or relationship to the device or procedure. The percentages should not be added, since the record does not establish that the categories are mutually exclusive.
In general, adverse-event summaries describe reported events and are not, by themselves, proof that an intervention caused an event. Interpretation also depends on follow-up duration, how events were collected and classified, and whether there is a suitable comparison group. Those details are not reported in the registry record. The single-group design means the safety figures are descriptive rather than a comparative estimate of risk.
12. What the Result Does, and Does Not, Mean
The record establishes that a prospective, multicentric, single-arm post-market study of InnFocus MicroShunt implantation was conducted in people with primary open-angle glaucoma. It reports enrollment of 107 participants, defines a primary endpoint based on participants meeting study success with respect to intraocular pressure, and specifies assessments at Month 6, 9, 12 and 24. It also provides selected adverse-event counts and serious-event terms.
The record does not report the numerical results for the primary endpoint or the secondary outcome of intraocular pressure change. It does not report the full definition of success, confidence intervals, or posted analyses. As a result, the registry information cannot establish the size or precision of the primary endpoint estimate. The absence of a numerical result in this record is not evidence that no result was observed; it means the result is not reported in the registry record.
The single-group design also defines what can be inferred. The study can describe outcomes and reported events among participants who received the device, but it has no concurrent control group in the registry record. Therefore, it cannot directly quantify how outcomes would compare with another treatment or with no implantation. An observed outcome in one group does not alone isolate the effect of the intervention from other influences.
The sample-size section is a planning illustration using stated assumptions and is not the study’s design rationale or observed power. It should not be read as evidence that the primary result was statistically significant, clinically important, or adequately precise. Likewise, the adverse-event counts are descriptive and do not establish causation or comparative safety.
In general, a fuller interpretation would require the endpoint definition, outcome estimates with uncertainty, the analysis methods, follow-up completeness, and details of how missing data and multiple assessments were handled. These items are not reported in the registry record. The available entry supports a description of study design and selected safety summaries, but not a conclusion about comparative effectiveness or causal effects.
13. Why This Trial Matters Statistically
This study is statistically notable as a post-market investigation with a prospective, multicentric, single-group design. It illustrates the distinction between documenting outcomes after an intervention and estimating a comparative treatment effect. A single-group study can provide descriptive information about participants who received a device, but without a concurrent control group it cannot directly estimate what would have happened to comparable participants under another approach.
The primary endpoint also highlights how much interpretation depends on an operational definition. The registry names participant success with respect to intraocular pressure and identifies assessment at Month 6, 9, 12 and 24. Yet the success threshold and numerical results are not reported in the registry record. A count-based endpoint may look straightforward, but readers need the classification rules, follow-up denominators, and uncertainty estimates to understand what the count represents.
The record includes an intent-to-treat population definition, but does not report how missing follow-up data were handled or how multiple time points and outcomes were treated statistically. These are not minor technical details: they affect how endpoint results should be interpreted and how confidently they can be compared across studies. The registry also records no posted analyses, which prevents readers from evaluating the actual statistical procedures.
Finally, the sample-size section illustrates a general difference between trial planning and retrospective planning calculations. Its assumptions describe a two-arm illustration, while this study is recorded as single-group. Keeping those distinct prevents a planning quantity from being mistaken for a trial feature or a measure of observed evidential strength. Together, these features make the record a useful case for examining design, endpoint definition, analysis transparency, and the limits of descriptive safety data.
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 main limitation for interpreting this study from the registry record is the absence of numerical primary endpoint results. Although the endpoint and follow-up points are named, the success criterion is not reported. The record therefore does not allow an independent assessment of the endpoint’s definition, its observed frequency, or its precision. Numerical results for the listed secondary outcome, intraocular pressure change, are also not reported in the registry record.
The single-group design is an additional limitation for causal and comparative interpretation. No separate comparator arm is described, so the registry cannot provide a direct estimate of the difference between the MicroShunt and another intervention. The record’s completed status and enrollment figure do not resolve this design limitation.
Other relevant methodological details are not reported in the registry record, including the statistical analysis plan, the study’s sample-size justification, missing-data methods, follow-up completeness at each time point, multiplicity procedures, and sensitivity analyses. The registry records no posted analyses. Without these details, readers cannot assess whether the reported endpoint summaries, if displayed elsewhere, reflect a prespecified approach or how robust they are to analytic choices.
The safety summary is also limited in scope. It reports participant counts, selected serious-event terms and percentages, and a death count, but does not report event timing, follow-up duration for safety, causal attribution, or whether event categories overlap. These omissions prevent a fuller comparison or assessment of risk. The planning illustration’s two-arm assumptions should not be confused with the actual single-group design, and it is not evidence of observed power.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Post Market Study of the InnFocus MicroShunt — NCT02177123.
- Registry record last updated 2021-06-24; status last verified 2021-06.
- Results first posted 2021-05-28.
- 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.
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18. Record Summary
The registry record describes a completed, prospective, multicentric, single-arm post-market study of InnFocus MicroShunt implantation in people with primary open-angle glaucoma. It reports enrollment of 107 participants and identifies the primary endpoint as the number of participants with study success with respect to intraocular pressure at Month 6, 9, 12 and 24. The intervention involved implantation in the anterior chamber after treatment with mitomycin C.
The registry lists intraocular pressure change as a secondary outcome and reports selected adverse-event summaries. The primary endpoint definition and numerical outcome results are not reported in the registry record, and the record lists no posted analyses. Because there is no separate comparator group, the study is descriptive rather than a direct randomized comparison. The planning illustration on the page should be understood as hypothetical, not as the study’s original sample-size design or observed power.