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 Evaluation of Binocular Visual Acuity and Refractive Stability in the Alcon Clareon Intraocular Lens (NCT04936256), a registered phase not stated study. The primary outcome is Refractive Stability.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04936256 |
| Phase | Phase not stated |
| Condition | Cataract |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 31 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Gainesville Eye Associates |
| Results posted | Yes |
2. Clinical Question
Population
Participants with cataract; the registry record reports enrollment of 31. Further eligibility details and participant characteristics are not reported in the registry record.
Intervention
Bilateral implantation of the Clareon monofocal intraocular lens. The intervention is listed as a device.
Comparator
No comparator is described as a like-for-like control. The registry record does not report allocation, and this is not a randomized comparison.
Primary question
At 3 months, what refractive stability was observed, with stability described as spherical equivalent change ≤ 0.50D from 1-month to 3-months?
The clinical question is about refractive stability after bilateral implantation, rather than a comparison of Clareon against another lens or a control group. The registry identifies binocular visual acuity measures as secondary outcomes, including uncorrected distance and intermediate acuity, corrected distance acuity, distance-corrected intermediate acuity, and a defocus curve.
The primary outcome is described using a change threshold, while the registry also specifies a mean in diopters and a 95% confidence interval. Those details identify the intended measurement and summary format, but the numerical estimate and its confidence interval are not reported in the registry record. The record therefore states what the study set out to evaluate, but does not establish what value was observed or how precise that estimate was.
The registry reports a single implantation group and does not identify a randomized control comparison. As a result, the stated clinical question should be read as an evaluation of outcomes after implantation in this enrolled group, not as an estimate of the difference between two treatment strategies.
3. Trial Design
This is a completed clinical trial sponsored by Gainesville Eye Associates. The condition listed is cataract, and the intervention is the Clareon device, described as a monofocal intraocular lens. The arm description specifies bilateral implantation. Enrollment was 31 participants.
The registry gives a start date of 2021-07-02 and a primary completion date of 2022-07-28. Its status is completed. These dates identify the recorded study timeline; they do not by themselves describe the length of follow-up for every participant or the timing of each assessment.
The primary outcome timeframe is 3 months. Its description focuses on whether spherical equivalent changed by no more than 0.50D from 1-month to 3-months. Binocular visual acuity outcomes are also listed, including distance and intermediate measures and a defocus curve. The registry lists six outcome measures in total.
The record does not report a like-for-like control group or a randomized allocation procedure. It also does not report allocation details. The planning assumptions described for sample-size illustrations refer to equal allocation between two arms, but that is a planning framework and should not be mistaken for the design actually used in this trial. The listed arm description is bilateral implantation of the Clareon monofocal IOL.
Other design details, including eligibility criteria, masking, the planned sample-size rationale, and the protocol’s statistical analysis plan, are not reported in the registry record. The completion status and enrollment count are not substitutes for those details. In particular, the record’s description permits a reader to identify the device, study group, outcome focus, and timeline, but not to reconstruct the full protocol or analysis procedures.
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 | Bilateral Implantation of the Clareon Monofocal IOL |
|---|---|
| STARTED | 31 |
| COMPLETED | 29 |
| NOT COMPLETED | 2 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: Only subjects who completed the study are included in the baseline analysis.
| Characteristic | Unit | Bilateral Implantation of the Clareon Monofocal IOL |
|---|---|---|
| Participants analysed | 29 | |
| Age, Continuous | years | 72.1 (SD 5.8) |
| Sex: Female, Male: Female | Participants | 13 |
| Sex: Female, Male: Male | Participants | 16 |
| Race and Ethnicity Not Collected | Participants | — |
6. Primary Endpoint
The registry lists the primary outcome as Refractive Stability, measured over 3 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Diopters (D) |
| Endpoint classification | Continuous Endpoint |
The primary endpoint concerns refractive stability, described as spherical equivalent change ≤ 0.50D from 1-month to 3-months. The registry identifies the timeframe as 3 months and specifies a mean in diopters with a 95% confidence interval as the summary format. The numerical outcome itself is not reported in the registry record.
In general, spherical equivalent is a summary of refractive error, and comparing its value at two visits is one way to describe whether refraction changes over time. A prespecified threshold can turn a continuous change into a practical definition of stability: the stated criterion treats a change at or below 0.50D across the stated interval as meeting the description of refractive stability. The record does not clarify how the threshold-based description relates to the listed mean summary, such as whether a separate proportion meeting the criterion was also intended.
Refractive stability is relevant to an evaluation of an intraocular lens because it describes the consistency of refractive measurements over the specified follow-up interval. It is distinct from visual acuity: the trial lists binocular visual acuity outcomes separately as secondary measures. A stability result would not, by itself, describe every aspect of visual function or establish a comparison with another lens.
Because no estimate or interval is reported, the endpoint definition can be explained, but the degree of observed change and the uncertainty around it cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record identifies a focused primary question: refractive stability at 3 months, defined by spherical equivalent change ≤ 0.50D from 1-month to 3-months. It also specifies that the intended summary is a mean in diopters with a 95% confidence interval. However, it does not report the mean, the interval, or an analysis for the primary outcome. The record therefore does not allow a reader to judge whether the observed measurements met the stated stability description or how precisely any estimate was determined.
The registry lists six outcome measures and no analyses. It names the primary outcome and several binocular visual acuity measures, but outcome names alone do not establish the values observed. Nor do they reveal how many participants contributed data at each visit, how missing observations were handled, or whether all planned measures were analyzed. Those details are not reported in the registry record.
In general, a confidence interval expresses uncertainty around an estimate under the assumptions of the analysis. A narrower interval indicates greater precision than a wider interval, while neither interval width nor the estimate itself is available for this primary outcome in the registry record. Without those values, there is no basis for describing the magnitude or precision of the observed refractive result.
The study is not presented as a randomized comparison. The registry does not describe a control group that would support a direct estimate of the difference between Clareon and another lens or treatment. The results, even if numerical outcomes were available, would need to be interpreted as observations from the recorded study group unless a suitable comparison were documented elsewhere in the registry record.
Enrollment was 31. That count describes the trial’s reported enrollment, not the number with complete primary outcome data. The number analyzed for the primary endpoint is not reported in the registry record. It would therefore be inappropriate to assume that every enrolled participant contributed a measurement at both visits.
The safety entries report zero serious adverse events among 31 at risk, zero other adverse events among 31 at risk, and one death. These counts have different meanings and should be read separately. The record does not report details about the death or its relationship to the device or study. These safety entries do not fill the gap in the primary outcome results and cannot establish the size or precision of refractive change.
Overall, the registry describes the aim, intervention, enrollment, endpoint definition, and selected safety counts. It does not report the primary numerical result, the confidence interval, or analyses of the named outcome measures. The statistical interpretation is consequently limited to the design and reporting information, not a conclusion about the outcome’s observed magnitude.
9. Statistical Methods Explained
The registry describes the primary outcome as a continuous measure summarized by a mean and 95% confidence interval. It also describes refractive stability using a threshold for spherical equivalent change. These are related but not identical ways to express an outcome: a mean summarizes values across participants, whereas a threshold can describe whether individual changes fall within a specified range. The registry does not report a numerical result or explain whether both summaries were planned or calculated.
What does a mean describe?
In general, a mean is the arithmetic average of measured values in the analysis group. It provides a compact description of the group’s central value, but it does not show how widely individual observations vary. Participants may have measurements clustered near the mean or spread across a broad range. A mean alone also does not show whether the observations include unusual values that could influence the average.
For this endpoint, the unit is diopters. The registry does not report the mean value, the number of observations included in its calculation, or a measure of the spread of individual values. It is therefore not possible to describe the group’s average refractive change from the registry record.
What does a confidence interval add?
In general, a confidence interval gives a range of values compatible with an estimate under the statistical method and assumptions used. It communicates precision: a more concentrated interval indicates a more precise estimate, while a broader interval indicates more uncertainty. A confidence interval is not a guarantee that the true value lies within the particular interval, and its interpretation depends on the analysis assumptions.
The registry specifies a 95% confidence interval for the primary mean, but does not report its endpoints. Consequently, neither the estimated mean nor its precision can be assessed. A confidence interval also does not replace the endpoint definition: readers need both the estimate and the clinical meaning of the measurement to interpret the result.
How should the stability threshold be understood?
In general, a threshold converts a continuous change into a rule for classifying measurements. Here, the description uses spherical equivalent change ≤ 0.50D between 1-month and 3-months. This makes the threshold understandable as a definition of stability over that interval. It does not tell readers how many participants met the criterion, what the average change was, or how values were distributed around the threshold. None of those outcome details is reported in the registry record.
The record’s pairing of a threshold-based description with a mean summary leaves an interpretive detail unresolved. A mean can be calculated for continuous measurements, but it does not directly state the proportion of participants whose individual change met a threshold. The registry does not report an additional threshold-based summary or clarify the relationship between the two descriptions.
What do the planning assumptions mean?
In general, sample-size calculations estimate how many observations a future study would need under specified assumptions. They are planning exercises, not evidence that an observed result is precise and not a measure of observed power. The planning framework described for this study uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It defines the effect to detect as a stated fraction of the observed effect.
Those assumptions do not establish that this trial had two arms or used equal allocation. The recorded design information describes bilateral implantation of the Clareon monofocal IOL and does not identify a like-for-like control comparison. The planning framework must be kept separate from the actual trial design. The numerical planning outputs and the observed effect on which such illustrations depend are not reported in the registry record. No planning illustration should be read as the number enrolled or as evidence that the study had a particular probability of finding an effect.
More generally, planning calculations depend on assumptions about the target effect, variability, significance level, power target, allocation, and analysis method. If those assumptions differ from the study’s actual conditions, the resulting planning figure may not describe the study’s ability to estimate its outcome. The registry does not report the trial’s own sample-size justification or full design assumptions.
Why does dispersion matter?
In general, variability among participant measurements affects the precision of a mean. Greater dispersion tends to make it harder to estimate a group mean precisely for a given amount of information. For outcomes with counts, over-dispersion means that the observed variation exceeds what a chosen model expects; accounting for it can be important to avoid overstating precision. The primary outcome is described as continuous, and no count model or over-dispersion adjustment is reported in the registry record.
These statistical concepts explain how an estimate could be interpreted if reported. They cannot supply missing trial results. The registry record provides the endpoint definition and intended summary format, but not the estimate, confidence interval, analysis population, or details of the calculation.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six outcome measures: refractive stability as the primary outcome and binocular uncorrected distance visual acuity, binocular uncorrected intermediate visual acuity, binocular corrected distance visual acuity, binocular distance-corrected intermediate visual acuity, and a binocular defocus curve as secondary outcomes. Considering multiple outcomes can raise multiplicity concerns because, in general, testing several hypotheses creates more opportunities for an apparently notable result by chance.
The registry does not report whether any adjustment for multiplicity was planned or used, nor does it describe a hierarchy or testing sequence for the secondary outcomes. No analyses are listed. The record therefore does not support an account of how multiple outcomes were handled or which results, if any, were considered confirmatory.
Missing-data methods are not reported in the registry record. The enrollment count of 31 does not establish how many participants had measurements available at 1-month or 3-months, or whether observations were excluded. The record does not describe imputation, complete-case analysis, sensitivity analyses, or reasons for missing assessments.
Analysis populations are also not reported. It is not possible to determine from the registry record whether the primary analysis included every enrolled participant, only participants with measurements at both visits, or another defined group. The record does not describe protocol deviations or how they were handled. These omissions limit assessment of the analysis and the possibility of reproducing it; they do not show that a particular method was or was not used outside the registry record.
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 |
|---|---|---|---|
| Bilateral Implantation of the Clareon Monofocal IOL | 0 | 31 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Bilateral Implantation of the Clareon Monofocal IOL | 1 of 31 |
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 |
|---|---|
| Bilateral Implantation of the Clareon Monofocal IOL | 0 of 31 |
The registry reports zero serious adverse events among 31 participants at risk and zero other adverse events among 31 participants at risk. It separately reports one death in the listed group. These are distinct safety counts, and the death should not be assumed to be included in either adverse-event count or to have been caused by the device or study.
The registry does not report details about the death, its timing, its cause, or its relationship to the intervention. It also does not list serious adverse event terms. The absence of a listed event term is not enough to infer an explanation for the death or to establish whether it was related to treatment.
In general, event counts are interpreted alongside the number at risk, the period of observation, the event definitions, and the method of collection. The record gives the at-risk counts but does not provide fuller information about exposure time, adjudication, or attribution. Zero reported events in this group does not by itself establish the absence of risk, and one death does not establish a causal relationship. The safety entries should be read as the counts recorded, with the available context and limitations.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the trial evaluated bilateral implantation of the Clareon monofocal IOL in 31 participants with cataract and that refractive stability was the primary question. The stated stability definition concerns spherical equivalent change ≤ 0.50D from 1-month to 3-months. The record also identifies binocular visual acuity outcomes and reports selected adverse-event counts.
It does not report a primary endpoint estimate or its 95% confidence interval. Therefore, the record does not establish the average refractive change, the precision of that estimate, or the number of participants meeting the stated stability criterion. It also does not report analyses for the listed outcome measures. Naming an outcome is not the same as reporting its result.
The study is not described as a randomized comparison, and no like-for-like control group is identified. Consequently, the record does not support a comparative estimate of the effect of Clareon relative to another lens or control. Nor can the endpoint definition alone establish that a particular outcome occurred. Such conclusions would require reported results and, for comparative claims, an appropriate comparison.
In general, a study result is interpreted by considering the size of the estimated effect, its uncertainty, the outcome definition, the analysis population, and design limitations. For this trial, the essential numerical primary result and several analysis details are not reported in the registry record. The interpretation must remain bounded by what the record states: the study aim, recorded design information, outcomes, enrollment, and safety counts.
The record’s completed status means the study is marked completed in the registry. It does not imply that every outcome result is reported there. The appropriate statistical reading is therefore descriptive and limited: the endpoint and study group are identified, but the reported material does not permit a conclusion about the observed refractive result or its precision.
13. Why This Trial Matters Statistically
This trial illustrates why a clear endpoint definition and a reported estimate are both needed for statistical interpretation. The registry defines refractive stability using a threshold for spherical equivalent change across a specified interval and names a mean with a 95% confidence interval as the summary. Without the numerical estimate and interval, readers can understand the planned question but cannot assess the outcome’s magnitude or precision.
It also highlights the importance of distinguishing a threshold description from a continuous summary. In general, a mean describes an average, while a threshold classification can describe how many individuals meet a criterion. Reporting both, where relevant, can address different questions. The registry record does not report whether a separate threshold-based result was calculated, so that distinction remains unresolved for this trial.
The design context matters as well. The recorded intervention is bilateral implantation in the listed study group, and the registry does not describe a randomized control comparison. Statistical conclusions must reflect that structure. A within-group outcome description is not the same as a comparative treatment effect, and a planning assumption involving two arms does not establish that the trial itself used two arms.
The record also shows why outcome reporting and analysis transparency matter. It identifies six outcome measures but lists no analyses, and it does not report missing-data methods or analysis populations. Without those details, readers cannot evaluate how the results were derived, how uncertainty was handled, or whether outcomes were treated as exploratory or confirmatory.
These are general statistical lessons drawn from the information recorded for this trial: endpoint definitions, estimates, uncertainty, design, and analysis procedures all contribute to a sound interpretation. Here, the endpoint and design are described more fully than the numerical results and analytical details.
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 principal limitation for interpreting this trial from the registry record is the absence of reported outcome estimates. Although the primary endpoint is defined and a mean with a 95% confidence interval is specified, neither the estimate nor interval is reported. The listed secondary outcomes likewise have no analyses reported. This prevents assessment of outcome magnitude and precision.
Enrollment was 31, but the number of participants contributing data to the primary analysis is not reported. The record does not describe missing observations, the analysis population, or the approach to incomplete follow-up. It is therefore not possible to determine whether the enrolled group and the analyzed group were the same.
The registry does not identify a like-for-like control group or randomized allocation. This limits the interpretation to the recorded study group and does not support a direct comparative effect estimate. Allocation details are not reported in the registry record.
The endpoint description combines a threshold for change with a mean summary. The record does not clarify whether the threshold was used to classify individual participants, whether a proportion meeting it was calculated, or how that description relates to the mean. This makes the intended reporting of the primary endpoint less clear than its measurement interval and unit.
Other relevant methods are not reported in the registry record, including eligibility details, masking, the sample-size justification, multiplicity procedures, and methods for missing data. The primary timeframe is 3 months, so the recorded endpoint addresses the stated interval; the record does not establish outcomes beyond it. For safety, one death is recorded, but its details and relationship to the intervention are not reported. These limitations restrict interpretation without establishing that any particular result or method was absent from study conduct beyond what the registry records.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of Binocular Visual Acuity and Refractive Stability in the Alcon Clareon Intraocular Lens — NCT04936256.
- Registry record last updated 2024-08-07; status last verified 2024-08.
- Results first posted 2024-08-07.
- 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
NCT04936256 is a completed trial sponsored by Gainesville Eye Associates, with 31 participants enrolled and cataract listed as the condition. The intervention is the Clareon monofocal intraocular lens, implanted bilaterally. The study start date is 2021-07-02 and the primary completion date is 2022-07-28.
The primary outcome is refractive stability at 3 months, described as spherical equivalent change ≤ 0.50D from 1-month to 3-months. The registry specifies a mean in diopters and a 95% confidence interval, but the numerical result and interval are not reported. Binocular visual acuity measures and a defocus curve are listed as secondary outcomes; the registry lists six outcome measures and no analyses.
The safety record reports zero serious adverse events among 31 at risk, zero other adverse events among 31 at risk, and one death. Details about the death and its relationship to the intervention are not reported in the registry record. The record does not describe a randomized comparison or report a control group.