Multiplexing Prism Fitting for Field Expansion of Monocular Vision: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Multiplexing Prism Fitting for Field Expansion of Monocular Vision (NCT06027216), a na na study. The primary outcome is Gain in Visual Field With the Multiplexing Prism.

2. Clinical Question

3. Trial Design

This completed study is registered as a single-group device study with an enrollment of 30. The intervention is the Multiplexing Prism, and the arm description identifies the assessment as field of view on the nasal side, with and without the prism. The registry lists no allocation and no masking. It does not describe a parallel control group or randomized assignment. Accordingly, the design information supports reading the principal comparison as a comparison of measurements taken with and without the device, rather than as a randomized comparison of separate treatment groups.

The primary outcome is Gain in Visual Field With the Multiplexing Prism. It is a continuous measure expressed in degrees and summarized using a mean and standard deviation. The stated timeframe is Visit 2 of the study, approximately 2-3 weeks after Visit 1. A secondary outcome is Maximum Extent of Nasal Visual Field With the Multiplexing Prism. The record lists 2 outcome measures and 0 analyses. Although it gives the primary outcome definition and a secondary outcome name, it does not provide outcome values, participant-level data, or analysis results.

The sponsor is Massachusetts Eye and Ear Infirmary. The listed start date is 2023-12-27, the primary completion date is 2024-10-22, and the status is COMPLETED. The phase is recorded as NA. The registry record does not report the protocol's sample-size justification, a prespecified statistical analysis plan, interim analyses, or the measurement sequence and procedures in enough detail to evaluate how the paired measurements were collected and analyzed. Completion status describes the study's recorded status; it does not itself establish that results were reported or that the device produced a particular amount of field expansion.

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:

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 Gain in Visual Field With the Multiplexing Prism, measured over Visit 2 of Study (approximately 2-3 weeks after 1st Visit).

The primary endpoint is Gain in Visual Field With the Multiplexing Prism, measured in degrees at Visit 2, approximately 2-3 weeks after Visit 1. It represents the difference between the maximum nasal visual-field extent on the side of the seeing or functioning eye that is also the side of the blind eye, measured with and without the prism. The endpoint is continuous, and the registry specifies a mean and standard deviation as its summary statistics.

In general, a continuous endpoint can retain information about the size and variation of individual measurements, rather than reducing the result to a yes-or-no category. A within-participant difference can describe how measurements change under two conditions for the same participant. That framing is relevant because the arm description refers to field of view with and without the device. Interpretation still depends on how measurements were taken, whether all participants contributed both measurements, and how missing observations were handled. Those details are not reported in the registry record.

The endpoint is intended to quantify the visual-field change associated with the prism under the study's measurement conditions. The registry record does not report the observed mean gain, standard deviation, confidence interval, or test result. Consequently, the endpoint definition explains what was measured, but the available record details do not establish the size or precision of the observed change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is described as continuous and summarized by a mean with a standard deviation. In general, a mean describes the central value of a set of measurements, while a standard deviation describes how dispersed those measurements are around the mean. Together, they give information about the observed values, but neither alone provides a complete account of uncertainty in an estimate. The registry record does not report either statistic for the primary outcome, so no numerical summary can be interpreted from the outcome definition alone.

What a paired contrast means

The endpoint definition uses the difference between visual-field measurements made with and without the prism. When both conditions are measured for the same participant, the natural quantity of interest is the within-participant difference. In general, analyzing participant-level differences preserves the pairing: each person's measurements are linked rather than treated as if they came from unrelated people. This can be useful when participants differ in their underlying visual-field extent, because the contrast focuses on change within each person.

The registry record's arm description is consistent with measurements with and without the device, but it does not spell out the analysis method. It does not report whether the primary analysis was performed on individual paired differences, whether all participants had both measurements, or how any incomplete pairs were treated. It also does not report the standard deviation of the differences. Separate summaries for each condition would not, by themselves, reveal the variability of the paired differences, because that variability also depends on how strongly the two measurements are related within participants.

What uncertainty measures would contribute

In general, a confidence interval describes a range of values compatible with the data and the assumptions of the analysis. It communicates uncertainty around an estimate and is more informative about precision than a point estimate alone. A hypothesis test can address whether data are inconsistent with a specified null model, but a p-value does not show the size of an effect or whether it is important in practice. The registry record does not report a confidence interval, p-value, or test result for the primary endpoint. No statistical significance conclusion can therefore be drawn from the record details available.

Precision depends on more than the mean and standard deviation in isolation. For a paired analysis, it depends on the spread of the within-participant differences and the number of participants with usable paired data. Although enrollment is 30, the number included in the primary endpoint analysis is not reported in the registry record. A confidence interval cannot be reconstructed from the enrollment figure alone, and no unreported result should be inferred from it.

Design and interpretation

In general, a measurement taken under two conditions in the same group can show a contrast between those conditions. It does not automatically establish that the condition caused the entire contrast. Measurement order, practice, assessor expectations, and changes over time can affect observations. The registry lists masking as NONE and describes a single-group design. It does not report the order of measurements, whether order was varied, or whether procedures were used to reduce measurement bias. These are considerations for interpreting a device-associated difference, not claims that any particular bias occurred.

Over-dispersion is a general concern when data vary more than a chosen statistical model assumes. If the model understates variability, standard errors and uncertainty intervals may be too narrow. The registry record does not report the distribution of the visual-field measurements or a model fit, so there is no basis for saying that over-dispersion occurred or that a specific adjustment was used. Likewise, the continuous outcome is described by a mean and standard deviation, but the record does not state whether the analysis made distributional assumptions or checked them.

Planning calculations and trial design

In general, sample-size calculations describe how many observations a planned design would need under stated assumptions; they are not evidence about the result observed in a completed study. A planning illustration based on an effect estimate is not the same as a prospective justification for enrollment, and it is not observed power. The registry record does not report the trial's sample-size justification or a prespecified analysis plan. It describes a single-group design, so calculations framed around equal allocation between two arms would not describe the registered design itself. Any such planning illustration should be interpreted only as a hypothetical calculation under its stated assumptions, not as the design used for this study or as a test of the study's success.

Finally, the registry lists 2 outcome measures and 0 analyses. That information identifies the scope of registered outcomes but does not tell the reader how the investigators analyzed them. The analysis population, handling of missing measurements, multiplicity approach, and any sensitivity analyses are not reported in the registry record. These details would be needed to evaluate whether the statistical methods matched the study question and how robust an estimate might be to alternative assumptions.

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("Amount of Visual Field Expansion")
n   <- c(22)
m   <- c(24)
sp  <- c(4)
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  Amount of Visual Field Expansion  22  24.000  4.000  22.226  25.774

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures: the primary gain in visual field and the secondary maximum extent of nasal visual field with the prism. It also lists 0 analyses. The number of registered outcomes alone does not reveal whether the outcomes were tested, whether one was designated as the principal basis for inference, or whether any adjustment for multiple testing was planned. A testing hierarchy, multiplicity adjustment, or rationale for interpreting multiple outcomes is not reported in the registry record.

In general, when several outcomes or statistical tests are considered, the chance of at least one apparently notable result can increase if each is interpreted independently. Methods for controlling or contextualizing this issue depend on the study aims and analysis plan. No such method is described in the registry entries available. This means the record does not support conclusions about how any multiplicity was managed; it also does not establish that investigators performed unreported tests.

Missing-data handling is another key element of an analysis plan. The record gives enrollment as 30 but does not report how many participants completed the measurements needed for each outcome, whether the primary endpoint required complete pairs, or how incomplete measurements were handled. It does not identify an intention-to-treat, per-protocol, or other analysis population. Those populations and procedures should not be assumed from the enrollment count or the study's completed status.

In general, exclusions or missing observations can affect an estimate if participants with available data differ from those without it. The direction and extent of any effect depend on the data and reasons for missingness, which are not reported in the registry record. Without the analysis population, missing-data approach, and outcome results, the robustness of a statistical conclusion cannot be evaluated from these details.

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 safety figures list 30 participants at risk for serious adverse events and 0 affected. The record also lists 30 at risk for other adverse events and 0 affected, with 0 deaths. These are counts as recorded, not estimates of risk over a defined follow-up period; the safety timeframe is not reported in the registry record.

A count of 0 affected means that no affected participants are recorded in the listed category for the group described. It does not prove that an event is impossible, nor does it establish that the device caused or prevented events. The study is single-group and does not provide a separate control group for a comparative safety assessment. The record does not provide event-level descriptions, severity details beyond the serious-event category, or the process used to collect and classify events.

The group label is Patient's Demography, and no serious-event terms are listed among the top serious terms. These registry fields should be read as reported safety counts, not as a complete assessment of all possible harms or of comparative safety. The record does not report enough detail to assess duration of observation, completeness of reporting, or attribution of events to the device.

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

The study asks a focused measurement question: whether nasal visual-field extent differs when measured with and without a multiplexing prism in people with acquired monocular vision. The registry record identifies the endpoint, its unit, the planned summary as a mean and standard deviation, and the approximate visit at which it is assessed. It also records enrollment of 30 and a completed status. These details explain what the study set out to measure and the broad design used.

However, the outcome values and statistical results are not reported in the registry record. Without an observed mean difference, a measure of variability, and an uncertainty estimate, the size and precision of the measured change cannot be judged. It is not possible to determine from these details whether observed values favored either measurement condition, how variable they were, or whether an analysis met a prespecified statistical criterion. The absence of reported results should not be interpreted as a null result.

The single-group structure also limits what a with-and-without comparison can establish. In general, a within-participant contrast can describe how measurements differ across conditions, but it is not equivalent to a randomized comparison against a separate control group. The record does not specify the measurement order or how possible order and assessment effects were addressed. It therefore does not permit separation of the device-associated contrast from all other influences on measurement.

The safety counts report 0 affected for serious and other adverse events among 30 at risk in each category, and 0 deaths. Those counts are useful descriptive registry information, but they do not establish the absence of all potential harms or provide a controlled comparison. Taken together, the record supports describing the study's aim, design, registered outcome definitions, enrollment, and recorded safety counts. It does not support a conclusion about the magnitude, precision, statistical significance, clinical importance, or causal interpretation of a visual-field effect.

14. Why This Trial Matters Statistically

This study is statistically notable for the way its primary question is framed. The endpoint is a continuous difference in visual-field extent, with measurements described with and without a device in a single group. Such a question is naturally interpreted through the participant-level contrast and its uncertainty, rather than through a comparison of unrelated groups. The registry record specifies the outcome unit and summary type, allowing readers to understand the intended estimand even though it does not report the estimate itself.

The study also illustrates why design labels and analysis details matter. A single-group study can characterize a measurement contrast, but it does not have the same protection against confounding as a randomized comparison. Masking is listed as NONE, and information about measurement order and assessment procedures is not reported in the registry record. These factors do not invalidate the observations, but they affect the strength of conclusions that can be drawn from a contrast.

Another statistical issue is the difference between enrollment and analyzed data. The record states enrollment of 30, but does not identify the number contributing complete outcome measurements or the analysis population. For paired measurements, complete pairs and variability in the individual differences are important to estimating precision. Without those details, enrollment alone cannot establish how informative the primary comparison was.

Finally, the record lists 2 outcomes and 0 analyses, but no primary endpoint result, uncertainty measure, or analysis plan. This makes transparent reporting especially important: definitions describe what was intended, while results and methods are needed to assess what was observed and how confidently it can be interpreted. The statistical importance of this study record lies in that distinction between a clearly defined measurement question and the missing information needed to evaluate its answer.

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 registry entries available leave important trial-specific limitations unresolved. The study is single-group, with no randomized allocation or separate control group. The endpoint description compares measurements with and without the prism, but the record does not report the order in which conditions were measured, whether order varied, or whether assessors were masked. Since masking is listed as NONE, expectations or assessment procedures could be relevant to measurement interpretation, although the record does not establish that any bias occurred.

The population description identifies acquired monocular vision and lists one eye blindness, blind left eye, and blind right eye. It does not report further participant characteristics, recruitment procedures, eligibility details, or the causes and duration of vision loss. The ability to assess how closely the enrolled group represents the intended population is therefore limited by the information in the registry record.

The primary outcome is defined, but its observed mean and standard deviation are not reported. The record also does not report a confidence interval, test result, or analysis method. Although enrollment is 30, the number with usable paired measurements and the analysis population are not reported. Missing-data procedures, protocol deviations, and reasons for any unavailable measurements are also not reported in the registry record.

The registry lists a secondary outcome and reports 0 analyses, but does not describe a statistical plan, multiplicity handling, interim analyses, or sample-size justification. The safety fields provide counts but do not identify a monitoring period, event descriptions, or attribution procedures. These gaps prevent assessment of the study's precision, analysis robustness, potential selection effects, and the completeness of safety reporting. They are limitations of the information recorded, not evidence that a particular outcome or bias occurred.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Multiplexing Prism Fitting for Field Expansion of Monocular Vision — NCT06027216.
• Registry record last updated 2025-05-08; status last verified 2025-04.
• Results first posted 2025-05-08.
• 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 device study sponsored by Massachusetts Eye and Ear Infirmary, with enrollment of 30. The intervention is a Multiplexing Prism, intended to expand the field of view for people with acquired monocular vision. Allocation is listed as NA and masking as NONE.

The primary endpoint is gain in nasal visual-field extent, measured in degrees as a mean and standard deviation at Visit 2, approximately 2-3 weeks after Visit 1. A secondary outcome is maximum extent of nasal visual field with the prism. The record lists 2 outcome measures and 0 analyses, but does not report endpoint values or statistical results.

Safety counts list 0 affected for serious adverse events and 0 affected for other adverse events, among 30 at risk in each category, with 0 deaths. The record does not report a statistical analysis plan, sample-size justification, analysis population, or missing-data method.