Examination of Myopia Progression and Soft Bifocal Contact Lens Myopia Control: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Examination of Myopia Progression and Soft Bifocal Contact Lens Myopia Control (NCT04080128), a registered phase not stated study. The primary outcome is The Statistical Correlation Between Three-year Change in Choroidal Thickness and Three-year Change in Axial Length.

2. Clinical Question

3. Trial Design

The registry record identifies NCT04080128 as a completed study sponsored by Ohio State University. The listed start date is 2019-09-09 and the primary completion date is 2024-01-04. Enrollment is listed as 248. The condition is myopia, and the intervention category is contact lenses. These administrative details describe the registered study; they do not establish which participants contributed data to the primary analysis.

The primary endpoint is an association between two changes measured over three years: change in choroidal thickness and change in axial length. The endpoint description says axial length is averaged over the right and left eye. It also states that the hypothesis concerns thinner subfoveal choroidal thickness being associated with greater axial elongation. The record describes the period as two years of multifocal contact lens wear followed by one year of single vision contact lens wear.

The arm description states that all participants wear +2.50 D multifocal contact lenses for the first two years, followed by single vision contact lenses in the last year. Separately, the safety record lists groups with different contact-lens regimen labels. The registry does not explain how these arm descriptions relate to the primary endpoint analysis, and it does not state allocation. It explicitly cautions that the listed arms are not a like-for-like control comparison. The record therefore does not support interpreting the primary endpoint as a randomized treatment contrast.

The study summary describes aims concerning biological associations with myopia progression and questions about soft bifocal contact lens myopia control. It says some aims depended on the outcome of the BLINK Study. Whether those conditional aims were conducted is not reported in the registry record. The record lists 13 outcome measures and 10 analyses, but does not provide the analysis populations, analytic methods for each outcome, or a complete account of how the aims were carried out.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Axial length average over right and left eye

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 The Statistical Correlation Between Three-year Change in Choroidal Thickness and Three-year Change in Axial Length, measured over Three years.

The primary endpoint is the statistical correlation between three-year change in choroidal thickness and three-year change in axial length. The endpoint description specifies subfoveal choroidal thickness, a layer of blood vessels, and describes greater axial elongation as greater eye growth. Axial length is defined as the average over the right and left eye. The measure is expressed in mm axial length, with the endpoint type listed as a mean and its dispersion listed as standard deviation.

A correlation describes the direction and strength of the relationship between two measured variables. In general, a negative association would mean that lower changes in one measure tend to occur with higher changes in the other, depending on how each change is coded. The registry’s stated hypothesis is specifically that thinner subfoveal choroidal thickness is associated with greater axial elongation. The record does not state the coding convention for change, so the sign of a correlation cannot be interpreted from the hypothesis alone.

Studying this association can address whether a biological measurement tracks with eye growth during the lens-wear period described in the record. It does not, by itself, show that a change in choroidal thickness causes a change in axial length. Nor does an association alone establish that the measure can predict progression in other patients. The posted record contains no correlation estimate, confidence interval, or test result for this endpoint, so the strength and precision of the association are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is described as a statistical correlation between change in choroidal thickness and change in axial length across three years. This is an association question, not a comparison of two means between treatment arms. The endpoint description identifies axial length as averaged over the right and left eye and gives the measure’s unit as mm axial length. It lists the summary parameter as a mean and the dispersion as standard deviation. The record does not name the correlation coefficient, specify a model, or report a result.

What does a correlation estimate describe?

In general, a correlation summarizes how two variables vary together. Its direction indicates whether larger values of one variable tend to occur with larger or smaller values of the other, while its magnitude indicates how closely the observations follow a linear pattern. A correlation is not a slope in the original measurement units, and it does not establish that one variable causes the other. The registry’s scientific hypothesis concerns thinner subfoveal choroidal thickness alongside greater axial elongation, but the record does not state how change is coded or which correlation method was used.

Correlation estimates can be affected by the range of measurements and by unusual observations. In general, a restricted range can make an association harder to detect, while influential observations can shift an estimate. The record does not describe diagnostic checks, transformations, handling of influential observations, or whether the association was examined for nonlinearity. These methods are not reported in the registry record.

How should uncertainty be assessed?

In general, a confidence interval gives a range of values compatible with the data under the assumptions of the analysis. A narrower interval indicates greater precision, while a wider interval indicates more uncertainty. A p-value addresses compatibility with a specified null hypothesis under an assumed statistical model; it does not measure the size or importance of an association. The registry record does not report a confidence interval, p-value, standard error, or other inferential result for the primary endpoint. The precision of the association therefore cannot be evaluated from the posted record.

The record’s endpoint description lists standard deviation as the dispersion measure. In general, standard deviation describes variation among individual measurements around their mean; it is not the same as the uncertainty around a mean or correlation estimate. A complete interpretation would distinguish observed variation in the measurements from uncertainty in the estimated relationship. The record does not provide the detailed statistical output needed to make that distinction for the primary analysis.

What does the study context allow?

The record describes a lens-wear sequence of multifocal lenses followed by single vision lenses and frames the primary question across that full period. Since the primary endpoint is a correlation over the study sample, it should not be read as a randomized estimate of the effect of one regimen versus another. The registry record says allocation is not stated and cautions that the listed arms are not a like-for-like control comparison. A correlation between two changes does not isolate the contribution of lens wear from other influences on either measure.

The registry summary describes biological associations with progression as part of the study’s aims. It also states that some later aims were conditional on the BLINK Study finding that soft bifocal contact lenses slowed myopia progression by 30% or more. Whether those aims proceeded is not reported in the registry record. This context does not supply a result for the current primary correlation.

What can planning calculations say?

In general, sample-size calculations based on an observed effect can illustrate the number of participants per arm needed to detect an effect under specified assumptions. Such calculations are planning illustrations, not observed power and not evidence that the study detected an effect. The registry description of planning assumptions refers to a two-sided significance level of 0.05, equal allocation, a normal approximation, and fractions of an observed effect. It does not provide the numerical planning results in the record, and the primary question is an association rather than the arm comparison represented by those assumptions. No planning value should be treated as a result of this endpoint.

For the primary association, key analytic details such as the coefficient, treatment of missing data, and adjustment strategy are not reported in the registry record. Without those details and the estimated association with its uncertainty, readers cannot reproduce or evaluate the primary analysis from the registry information alone.

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("Contact Lens")
n   <- c(234)
m   <- c(0.18)
sp  <- c(0.19)
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  Contact Lens  234  0.180  0.190  0.156  0.204

11. Multiplicity, Missing Data and Analysis Populations

The record lists 13 outcome measures and 10 analyses. It does not report a multiplicity plan explaining whether any outcomes or analyses were designated as confirmatory beyond the named primary endpoint, or whether statistical tests were adjusted for multiple comparisons. When several outcomes or analyses are considered, the chance of finding an apparently notable result by chance can increase. In general, prespecifying a hierarchy or applying an appropriate adjustment can help address this issue, but the registry does not state what approach was used. The missing information does not establish that an adjustment was required or omitted; it means the approach is not reported in the registry record.

Information about missing measurements is also not reported in the registry record. The record does not state how many participants contributed paired choroidal-thickness and axial-length measurements, how missing values were handled, or whether any participants were excluded from the primary analysis. It does not describe imputation, sensitivity analyses, or assumptions about why data might be missing. Enrollment therefore cannot be treated as the primary analysis sample.

The analysis population is not defined in the primary endpoint information. The record does not say whether the primary analysis included all enrolled participants, participants with complete measurements, or another specified group. Nor does it report exclusions or deviations relevant to the endpoint. These details are important because analysis-population choices can affect both the estimate and its interpretation.

The record provides a broad account of aims and outcome measures but not a complete statistical analysis plan. The planned handling of multiplicity, missing data, and analysis populations is not reported in the registry record. Consequently, the posted information is insufficient to assess whether the reported analyses, if any, followed a prespecified approach or how robust they are to alternative analytic choices.

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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: allergic reaction: non-ocular (1.3%), concussion (1.3%), headache (1.3%), mental health issue (1.3%).

The safety record lists serious-event counts separately for three contact-lens regimen groups. For +2.50 D/+2.50 D Multifocal Contact Lens, 78 were listed at risk and 4 were listed as affected by serious events; deaths were 0. For +1.50 D/+2.50 D Multifocal Contact Lens, 84 were listed at risk and 0 were listed as affected by serious events; deaths were 0. For Single Vision Contact Lenses (SVL)/+2.50 D MCL, 86 were listed at risk and 1 was listed as affected by serious events; deaths were 0.

These are descriptive counts in the registry record, not a randomized comparison of safety between groups. The record cautions that allocation is not stated and the arms are not a like-for-like control comparison. It does not provide enough detail to establish whether the groups had comparable follow-up, risk, or event ascertainment. No relative risk or other comparative statistic is reported, and none should be inferred from these counts alone.

The most frequently listed serious-event terms are Allergic reaction: non-ocular, Concussion, Headache, and Mental health issue, each recorded as 1.3%. The record does not identify those percentages by treatment group in the information presented. Other adverse-event counts are listed separately from serious events. Serious-event counts do not by themselves describe all tolerability outcomes, and the posted record does not establish a causal relationship between a lens regimen and an event.

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

The registry record defines a clinically relevant statistical question about whether change in subfoveal choroidal thickness tracks with change in axial length during the described lens-wear period. It describes the study as part of a broader effort to examine biological associations with myopia progression and questions about soft bifocal contact lens myopia control. This explains the scientific context, but it is not a result.

The primary correlation estimate and its uncertainty are not reported in the registry record. Therefore, the posted information does not show the observed direction or strength of the association, nor how precise the estimate is. It cannot establish whether the data support the stated hypothesis that thinner choroidal thickness is associated with greater axial elongation. Lack of a posted result is not evidence for a zero association or for any other particular outcome.

Even a clear association would not demonstrate that choroidal thickness causes axial elongation, or that changing choroidal thickness would change eye growth. It would not alone validate choroidal thickness as a predictor for individual patients, identify who would benefit from a lens regimen, or establish effects of stopping treatment. Such interpretations would require evidence and analyses beyond a correlation between changes.

The listed safety counts are descriptive and do not provide a reliable comparative estimate between lens regimens, especially given the record’s statement that the arms are not a like-for-like control comparison. They should not be interpreted as proof that a regimen causes or prevents serious events. The record’s completed status does not alter these limits: completion is not a substitute for posted outcome estimates, uncertainty intervals, and analytic details.

Overall, the record is informative about the planned biological question, endpoint definition, lens-wear context, and the existence of safety listings. It does not provide the numerical primary result or enough analysis detail to determine what the study found statistically.

14. Why This Trial Matters Statistically

This study’s primary question illustrates a useful distinction in clinical research: a biological association is not the same as a treatment effect. The endpoint relates changes in choroidal thickness to changes in axial length over the study period. That can help characterize whether two measures vary together, but it does not isolate a causal effect of contact lenses or establish that one measurement can guide treatment decisions.

The endpoint also makes interpretation depend on clear definitions. The registry identifies subfoveal choroidal thickness, three-year change, and axial length averaged over the right and left eye. Those details help define the intended relationship. At the same time, the record does not specify the statistical coefficient, sign convention for change, or uncertainty estimate. This demonstrates why endpoint labels alone do not replace reporting the analytic method and result.

The study description connects measurements of eye structure with progression and a sequence of lens wear. The registry’s broader summary also describes biological aims and questions about side effects, mechanisms, and discontinuation. Those topics may be important, but their relevance cannot be quantified from the record without the corresponding outcome results and methods. The primary association cannot stand in for answers to all those questions.

Finally, the safety listings and regimen labels highlight the need to distinguish descriptive data from comparative evidence. The registry states that allocation is not stated and the arms are not a like-for-like control comparison. That caveat limits what can be inferred from between-group counts. The record’s missing primary estimate, uncertainty, and analysis details also show why transparent results reporting is essential: readers need those elements to judge both the findings and their limitations.

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 limitation for interpretation is that the registry record does not report the primary correlation estimate or its precision. Without the estimate, confidence interval, or test result, the central association cannot be evaluated. The record also does not name the correlation method or explain how change was coded, which limits interpretation of direction and reproducibility.

The registered endpoint is framed across a period with multifocal contact lens wear followed by single vision contact lens wear. It is an association between two changes, not a stated randomized contrast. The record says allocation is not stated and the listed arms are not a like-for-like control comparison. The primary analysis therefore cannot be treated as evidence of a comparative lens effect based on the available description.

The record does not report the number of participants with complete primary measurements, the handling of missing data, exclusions, or the analysis population. Although enrollment is listed as 248, the number analyzed for the correlation is not reported in the registry record. The absence of these details prevents assessment of whether missing or selectively available measurements could affect the estimate.

The record lists multiple outcomes and analyses but does not state a multiplicity strategy, a detailed statistical analysis plan, adjustment variables, or sensitivity analyses. Whether these methods were used is not reported in the registry record. In addition, the study summary describes some aims as conditional on findings from the BLINK Study, but it does not say whether those aims proceeded.

The safety groups also require caution: the registry states they are not a like-for-like control comparison, and the detailed comparability and event-ascertainment information is not reported in the registry record. These limitations mean the posted details support description of the registered questions and recorded counts, but not strong comparative or causal conclusions.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Examination of Myopia Progression and Soft Bifocal Contact Lens Myopia Control — NCT04080128.
• Registry record last updated 2026-06-02; status last verified 2026-03.
• Results first posted 2026-05-06.
• 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

NCT04080128 is a completed study sponsored by Ohio State University, with enrollment listed as 248. The registry lists a start date of 2019-09-09 and a primary completion date of 2024-01-04. The condition is myopia, and the intervention category is contact lenses.

The primary endpoint is the statistical correlation between three-year change in choroidal thickness and three-year change in axial length. The stated hypothesis links thinner subfoveal choroidal thickness with greater axial elongation, with axial length averaged over the right and left eye. The record describes multifocal lens wear followed by single vision lens wear.

The primary correlation estimate, confidence interval, p-value, analysis population, missing-data approach, and detailed statistical plan are not reported in the registry record. Safety counts are listed for three regimen groups, but the record cautions that they are not a like-for-like control comparison. The registered information defines the study question and context but does not provide enough results to assess the primary association or draw comparative conclusions.