Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma (NCT03187418), a na na study. The primary outcome is Intraocular Pressure (IOP).

2. Clinical Question

The study asks whether treatment with MicroPulse trans-scleral cyclophotocoagulation is followed by a change in intraocular pressure among adults with uncontrolled glaucoma. The registered primary outcome is intraocular pressure, measured in millimeters of mercury at 18 months. The record also lists secondary measures concerning intraocular pressure, repeat treatment, pressure-lowering medication, visual acuity, optic nerve appearance, and visual field function.

This design can describe outcomes among participants who received the procedure, but it cannot by itself distinguish a treatment-associated change from other explanations, such as changes over time or concurrent care. The registry record does not report a control group or a comparative estimate.

3. Trial Design

The registry record describes a completed, single-group study at the University of Montreal Hospital Center. It lists enrollment of 52 and one intervention: a treatment session of micropulse trans-scleral cyclophotocoagulation in the affected eye. The intervention uses the MicroPulse P3 Glaucoma Device, powered by the CYCLO G6 Glaucoma Laser System. The study’s stated purpose is to evaluate the efficacy and safety of this procedure in adults with uncontrolled glaucoma.

The allocation field is NA, and the study model is single-group. No separate control arm is listed. Masking is recorded as none. These features mean that the record does not describe random assignment or blinded assessment. The study is therefore not a like-for-like comparison of the procedure against another treatment or a control condition. Its outcome descriptions need to be read as observations within a treated group, not as estimates of a difference between randomized groups.

The listed study dates are 2017-06-19 for the start and 2020-02-15 for primary completion; the status is completed. The phase is recorded as NA. The primary outcome is mean intraocular pressure at 18 months, measured with a Goldmann applanation tonometer. Other listed outcomes include repeat treatments, pressure-lowering medication, corrected distance visual acuity, cup-to-disc ratio, and visual field measures.

The registry record lists 13 outcome measures and 0 analyses. It does not report a statistical analysis plan, a sample-size justification, or how participants were included in outcome analyses. The assumptions stated for planning illustrations describe a hypothetical two-arm calculation based on an observed effect, but no planning results or observed effect are reported in the record. Those assumptions do not establish the study’s original design rationale.

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

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.

6. Primary Endpoint

The registry lists the primary outcome as Intraocular Pressure (IOP), measured over 18 months.

Intraocular pressure (IOP) is the study’s primary endpoint. It is a continuous measurement recorded in millimeters of mercury, with the registry specifying a mean and standard deviation at 18 months. Measurement is described as using the Goldmann applanation tonometer. The endpoint therefore concerns the distribution of measured pressure in the study group at the stated follow-up time.

IOP is used in glaucoma research as a measurable clinical outcome related to pressure in the eye. Reporting a mean gives a summary of the group’s measured values, while the standard deviation describes how dispersed individual values are around that mean. Neither summary, on its own, indicates how much each participant changed from baseline. The record does not specify a baseline-to-follow-up change as the primary outcome, nor does it describe an adjusted comparison.

The 18-month time point gives the endpoint a defined follow-up horizon, but the registry record does not report the mean, standard deviation, number assessed, or an estimate of change at that time. It also does not report a confidence interval or a statistical test for the primary outcome. Consequently, the registered endpoint can be described, but its observed level, variability, and precision cannot be evaluated from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies the primary outcome as a mean, a continuous summary measure, and names standard deviation as its dispersion measure. It also states that no analyses are listed. The concepts below explain how such statistics are generally read; they do not describe analyses reported for this study.

What does a mean describe?

In general, the mean is an arithmetic summary of measured values. It gives a central value for a group, but does not show the full distribution. Two groups can have the same mean while their individual observations vary in different ways. For IOP, the mean would summarize the recorded pressure values among participants contributing measurements at the specified time point. The registry record does not provide that mean or the number of participants whose measurements contributed to it.

What does the standard deviation add?

In general, the standard deviation describes how spread out observations are around their mean. A smaller standard deviation indicates that observed values are closer to the mean; a larger one indicates more dispersion. It is not the same as the uncertainty of the mean. The registry record names standard deviation for the primary outcome but does not post its value.

How would a confidence interval help?

In general, a confidence interval expresses the precision of an estimate under the model and assumptions used to construct it. A narrower interval indicates greater precision than a wider interval for the same estimated quantity. It does not describe the range containing every individual participant’s value, and it is not a guarantee about the true value. No confidence interval for the primary IOP outcome is reported in the registry record.

Why does the single-group design matter?

In general, a single-group follow-up can describe the observed outcome in participants who receive an intervention. It does not provide the concurrent contrast needed to separate an intervention-associated outcome from changes that might also occur without that intervention. Random allocation, when used in a comparative study, helps make groups comparable on average; it is not listed for this study. Here, allocation is NA and the model is single-group, so a between-group treatment effect is not available from the registered design.

What can be learned from a follow-up measurement?

In general, a measurement at a stated time point answers a different question from a change score. A follow-up mean describes the outcome level among those measured at follow-up. A change analysis would require a defined baseline measure and a specified method for relating baseline to follow-up. The registry record names the 18-month IOP outcome but does not specify a primary change-from-baseline analysis. It also does not report the baseline or follow-up values.

How should planning calculations be understood?

The registry record describes planning illustrations based on an observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says that the target effect is a stated fraction of the observed effect. Such calculations are hypothetical planning illustrations, not observed outcomes and not evidence of the achieved statistical power of this single-group study. The record does not report the resulting participant counts for planning, the observed effect used in those calculations, or the study’s original sample-size justification. The two-arm assumptions do not match the registered single-group design, so they should not be read as a description of the actual allocation.

More generally, an analysis plan would specify the estimand, analysis population, handling of repeated or incomplete observations, and statistical model. Those details are not reported in the registry record. Without the outcome values and analysis specification, the statistical methods actually used for the primary endpoint cannot be evaluated from the posted record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Micropulse Trans-scleral CPC")
n   <- c(52)
m   <- c(15.2)
sp  <- c(4.1)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Micropulse Trans-scleral CPC  52  15.200  4.100  14.059  16.341

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 13 outcome measures, including the primary IOP measure and secondary outcomes related to further treatment, medication use, visual acuity, optic nerve appearance, and visual field function. Examining multiple outcomes can raise a multiplicity question: when several statistical tests are performed, the chance of at least one apparently notable finding can increase. General approaches include defining one primary test in advance or adjusting interpretation across a family of tests. The registry record does not report a multiplicity strategy, planned contrasts, or results of statistical tests. It lists 0 analyses, so no registered analysis results can be assessed for multiplicity.

Missing-data methods are also not reported in the registry record. Enrollment is listed as 52, but the number with IOP data at 18 months is not given. There is no account of missed visits, withdrawals, unavailable measurements, or how any incomplete observations were handled. It is therefore not possible to determine whether the primary result, if analyzed, would represent all enrolled participants or a subset with available data.

The primary outcome’s population field is blank, and no analysis population is described. The registry record does not say whether analyses were intended to include everyone enrolled, participants who received the intervention, or another defined group. These are important distinctions: the population included and the treatment of missing outcomes can affect the meaning of an estimate. No assumptions about those choices should be inferred from enrollment alone.

12. 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.

The registry record reports 0 serious adverse events among 52 participants at risk in the micropulse trans-scleral CPC group. It also reports 0 other adverse events among 52 participants at risk and 0 deaths. These are the posted counts for the listed group; the record does not provide additional serious adverse event terms.

A zero count means that no events of the listed type were recorded in this registry summary for the stated group and at-risk count. It does not establish that the risk is absent, and it does not show how event rates would compare with another treatment or with no treatment. The study is single-group and lists no control arm, so comparative safety estimates are not available from its registered design.

The registry record does not report details such as event definitions, event ascertainment procedures, duration of safety monitoring, or a separate analysis of risk over time. The counts should therefore be read as a concise registry report rather than a complete account of all safety information. They do not replace the missing efficacy results or resolve the uncertainty about outcomes beyond the reported counts.

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

The registry record identifies a completed study of micropulse trans-scleral cyclophotocoagulation in adults with uncontrolled glaucoma. It gives the intervention, lists enrollment of 52, and names mean IOP at 18 months as the primary outcome. It also reports zero serious adverse events, zero other adverse events, and zero deaths in the listed group. These registry entries describe the registered study and its posted safety counts.

The record does not report the primary IOP result or results for the secondary outcomes. It supplies no outcome mean, standard deviation, confidence interval, or statistical test. It is therefore not possible to determine from the posted results what IOP values were observed at follow-up, how variable they were, or how precise an estimate might be. The absence of an analysis result in the registry should not be converted into a claim that the result was null or that the study found no change.

The design also does not support a randomized comparison. The study is single-group, allocation is NA, and no comparator is listed. Even if outcome measurements were available, a before-and-after description would not by itself establish that the intervention caused the observed pattern. Changes could have more than one explanation, and the registry record does not supply a comparison to address that issue.

Likewise, the posted safety counts are not proof that no adverse effects can occur. They are limited to the counts recorded in this summary and lack comparative context and additional detail about monitoring. The most defensible reading is that the registry documents the study’s planned clinical question and design, while the posted record does not contain the data needed to judge its primary outcome or quantify uncertainty around it.

14. Why This Trial Matters Statistically

This study is statistically instructive because its clinical question and its design answer different parts of an evidence question. The registry names an outcome at a defined follow-up time and specifies how IOP is measured. That provides a clear description of what was intended to be assessed. But a well-defined endpoint is not itself an outcome result: the registry record does not report the mean, variability, or precision of the 18-month measurement.

The single-group structure is central to interpretation. A group’s observed follow-up values can describe what was measured among participants, but a treatment effect requires a defensible comparison. No comparator group or randomized allocation is listed. This distinction helps prevent a descriptive result from being interpreted as a causal contrast that the registered design does not provide.

The record also illustrates why enrollment and analysis counts must be kept distinct. Enrollment is listed as 52, but the number contributing the primary outcome at follow-up is not reported. Without a participant flow or analysis population, readers cannot judge the extent of missing outcome data or who is represented by an estimate.

Finally, the registry lists multiple outcome measures but no analyses. That leaves both the reported findings and the approach to multiplicity unavailable for review. A registry record can establish the stated study framework, but interpreting evidence also requires outcome estimates, uncertainty measures, and analysis details. Those elements are not reported, so the statistical contribution of the study cannot be judged from the posted results alone.

15. 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 trial-specific limitation for interpreting results is that the registry record does not report the primary IOP estimate or analyses for the listed outcomes. In particular, it gives no 18-month mean, standard deviation, confidence interval, or number assessed at that time point. Without these, the outcome magnitude, variability, and precision are not reported in the registry record.

The study is registered as single-group, with allocation NA and no comparator. This means the record does not support a randomized comparison or a comparative estimate. Masking is recorded as none, and the record does not describe blinded outcome assessment. No conclusions about the consequences of these design features for measurement can be drawn from the registry information alone.

Although enrollment is listed as 52, participant flow and the analysis population are not described. The number with complete follow-up, reasons for missing measurements, and handling of missing data are not reported in the registry record. The primary outcome population field is blank. These omissions prevent assessment of whether the intended participants and the observed outcome data align.

The record lists multiple secondary outcomes but does not report an analysis plan, multiplicity approach, or analysis results. It also does not report a sample-size justification or the original statistical plan. The planning assumptions in the registry refer to hypothetical two-arm illustrations, while the registered study is single-group; no resulting planning counts are reported. Finally, safety reporting is limited to event counts in the registry summary, without further descriptions of monitoring or ascertainment.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma — NCT03187418.
• Registry record last updated 2021-10-08; status last verified 2020-08.
• Results first posted 2021-10-08.
• 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.

19. Record Summary

The registry record describes a completed, single-group study of micropulse trans-scleral cyclophotocoagulation in adults with uncontrolled glaucoma. It lists enrollment of 52 and a treatment session in the affected eye using the MicroPulse P3 Glaucoma Device. Allocation is NA, masking is none, and no comparator group is listed.

The primary outcome is mean intraocular pressure in millimeters of mercury at 18 months, measured with a Goldmann applanation tonometer. The record lists 13 outcome measures and 0 analyses. It does not report the primary outcome estimate, uncertainty, follow-up analysis population, or missing-data approach. Safety counts are 0 serious adverse events, 0 other adverse events, and 0 deaths among 52 at risk. These counts have no registered comparator for a relative safety assessment.