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 a New Silicone Hydrogel Contact Lens (NCT01309880), a randomized na study. The primary outcome is Visual Acuity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01309880 |
| Phase | NA |
| Condition | Myopia |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | Single |
| Enrollment | 66 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bausch & Lomb Incorporated |
| Results posted | Yes |
2. Clinical Question
Population
The primary outcome population is described as all eligible, dispensed eyes in people with myopia. The registry record lists enrollment of 66, but does not explain how that enrollment relates to the eye-level outcome population or how eligibility and dispensing were defined.
Intervention
The investigational device is described as a new silicone hydrogel contact lens, called the Test Lens in the arm description. The study objective was to assess clinical feasibility and product performance. The record does not give further details about lens characteristics or fitting procedures.
Comparator
The comparison device is Air Optix Aqua, described in the record as a Ciba Vision daily wear contact lens. The record does not specify further details about how the comparator was fitted, dispensed, or used during the study.
Primary question
The primary outcome concerns distance, high-contrast visual acuity measured in logMAR for the two lenses at dispensing and at one-week follow-up. The registry record does not report the visual acuity values or a statistical comparison, so it cannot establish the direction or size of any difference.
In statistical terms, the study asks whether visual-acuity measurements differ between the investigational lens and the comparator over the stated assessment occasions. That is a description of the question, not a conclusion about the lenses. The record identifies randomized allocation, single masking, and a crossover model. A crossover design is generally intended to compare interventions within participants across treatment periods, but the record does not describe the treatment sequence, period structure, washout, or whether the same eyes were assessed under both lenses. Those details matter when interpreting a crossover comparison, and they are not reported in the registry record.
3. Trial Design
The registry record identifies this as a randomized, single-masked, crossover study of contact lenses. Enrollment is recorded as 66, the condition is myopia, and the study status is completed. The phase is listed as NA. The sponsor is Bausch & Lomb Incorporated. The recorded start and primary completion are both 2010-12. The stated objective is to determine clinical feasibility and evaluate product performance of investigational contact lenses developed by the sponsor.
The interventions are the Test Lens, an investigational silicone hydrogel contact lens, and Air Optix Aqua, described as a Ciba Vision daily wear contact lens. Randomized allocation means assignment involved a random process, but the record does not state how the random sequence was generated or concealed. Single masking indicates that masking was recorded, but the record does not identify which people were masked or how masking was maintained.
In general, a crossover design compares interventions across periods within the same participants. This can make within-participant comparisons useful because each participant can serve as their own reference. It also makes sequence, period, and carryover effects relevant to analysis. The registry record does not report the order in which lenses were used, the duration of each period, any washout interval, or an approach to accounting for period or carryover effects. It also does not explain whether the randomized units were participants, eyes, or another unit.
The primary outcome is distance high-contrast lens visual acuity, described for dispensing and one-week follow-up. The record lists slit lamp findings and comfort as secondary outcomes. Although the study is marked completed, completion status alone does not supply outcome estimates or confirm which planned analyses were carried out. The registry record lists zero analyses and does not report the primary outcome results, statistical analysis plan, sample-size justification, or protocol details needed to assess implementation of the design.
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.
Before assignment: A total of 66 participants (132 eyes) were enrolled in the study. One-half (33) were randomized to receive the investigational RD2117-01 ID4 contact lens first, and the other half (33) was randomized to receive the Air Optix Aqua contact lens first then crossed over after 1 week. All participants completed the study.
Overall Study
| Stage | Air Optix Aqua Then Test Lens | Test Lens Then Air Optix Aqua |
|---|---|---|
| STARTED | 33 | 33 |
| COMPLETED | 33 | 33 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: All Eligible, Dispensed Eyes
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: All eligible enrolled participants
| Characteristic | Unit | Overall Study |
|---|---|---|
| Participants analysed | 66 | |
| Age, Continuous | years | 36.2 (SD 9.6) |
| Sex: Female, Male: Female | Participants | 47 |
| Sex: Female, Male: Male | Participants | 19 |
| Region of Enrollment: United States | participants | 66 |
6. Primary Endpoint
The registry lists the primary outcome as Visual Acuity, measured over Dispensing & 1-week follow up.
| Element | Registry entry |
|---|---|
| Result type | Least Squares Mean |
| Measure of spread | Standard Deviation |
| Unit | logMAR |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is distance, high-contrast visual acuity measured in logMAR for the study lenses at dispensing and at one-week follow-up. The record describes the statistic as a least-squares mean with standard deviation and identifies the population as all eligible, dispensed eyes. The outcome description frames the assessment as a comparison between Air Optix Aqua and the Test Lens at both occasions.
Visual acuity is a measure of how clearly a person can resolve visual detail under specified testing conditions. The high-contrast and distance descriptors define the setting of the measurement; they do not describe every aspect of everyday vision. On the conventional logMAR scale, lower values indicate better measured acuity. This is general interpretation of the scale and does not indicate which lens had a lower value in this study.
A least-squares mean is generally a model-based mean adjusted for terms included in the statistical model. Its interpretation depends on the model specification and the population analyzed. The registry record names this summary measure but does not report the model terms, the estimates, or the standard deviations. It also does not explain how results from the two assessment occasions were combined, if at all.
Visual acuity is used as an objective performance measure for a lens under defined testing conditions. It addresses a particular aspect of lens performance, while the listed secondary outcomes—slit lamp findings and comfort—cover other domains. The registry record does not report values for any of these outcomes, so the endpoint description clarifies what was intended to be measured but does not establish the observed result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record gives the design and outcome definitions but not the primary outcome results. It does not report least-squares means, standard deviations, a contrast between lenses, confidence intervals, or p-values. As a result, the direction, magnitude, and statistical precision of any visual-acuity difference cannot be assessed from the registry record. The record also lists zero analyses, so there is no reported analysis to interpret alongside the endpoint description.
The outcome was measured at dispensing and one-week follow-up. These are separate assessment occasions, and a comparison at one occasion would not necessarily answer the same question as a comparison at the other. The registry record does not state whether the intended inference was about each occasion separately, a change across occasions, or a combined estimate. It also does not provide results by occasion. The record’s note that the primary outcome has several categories or time points and was not reduced to one comparison is consistent with caution against presenting one overall estimate when the underlying assessment structure is not specified.
In general, a confidence interval describes the range of effect estimates compatible with the data and the method used, subject to the model’s assumptions. Its width conveys precision: a wider interval indicates less precision than a narrower interval. Because no interval is reported, precision cannot be evaluated. A p-value, if reported, would address compatibility with a specified null model under the analysis assumptions; it would not by itself describe the size or practical importance of an effect. No p-value is reported in the registry record.
The crossover designation could support within-participant comparisons, but interpretation depends on the actual sequence and analysis. For example, a period effect occurs when measurements differ across periods for reasons other than the lens being compared. Carryover refers generally to an effect of an earlier intervention persisting into a later period. These are general considerations for crossover studies, not findings about this trial. Sequence, period, and carryover handling are not reported in the registry record.
The completed status should not be mistaken for evidence that a particular result was favorable, unfavorable, or statistically conclusive. The study objective describes feasibility and product performance, but the available record does not give outcome values or an analysis that would support a comparative conclusion. The reported information therefore supports a description of the research question and design, not a judgment about the observed visual-acuity comparison.
The safety figures are also limited to the counts recorded for the listed intervention groups. They show zero serious adverse events and zero other adverse events in the recorded groups, with 66 at risk in each. Deaths are recorded as null rather than as zero. These entries should be read as registry fields, not as proof that no event occurred outside the scope or reporting conventions of the record. The crossover design also means group entries should not be added to infer a count of distinct participants.
Any sample-size planning illustration is a planning exercise rather than an observed trial result or observed power. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The registry record does not report the trial’s own sample-size justification or a numerical planning result. Those assumptions cannot replace the missing outcome estimates or analysis.
9. Statistical Methods Explained
The registry record identifies a continuous primary outcome summarized as a least-squares mean with standard deviation. It does not report an analysis, model specification, estimate, or uncertainty interval. The concepts below are general explanations of the statistical methods and design issues relevant to interpreting the outcome description, rather than a claim about what analysis was performed.
What does a least-squares mean represent?
A least-squares mean is generally an estimated mean derived from a statistical model. Unlike a simple arithmetic average, it can account for model terms such as treatment, assessment occasion, or design factors. The exact meaning depends on which terms were included and how the estimate was calculated. Here, the record names a least-squares mean but does not identify the fitted model, its covariates, or the contrasts used. Without those details and the estimate itself, the term does not tell the reader what value was observed or how the lens comparison was adjusted.
The record also lists standard deviation as the measure of dispersion. In general, standard deviation describes how spread out individual measurements are around a mean. It is not the same as the standard error, which describes the precision of an estimated mean, and it is not a confidence interval. The registry record does not report any standard deviation values, so the variability of measured visual acuity cannot be judged.
Why does the crossover structure matter?
In general, crossover studies allocate interventions across treatment periods so that participants may receive more than one intervention. A within-participant comparison can account for stable differences between participants, but it does not remove every source of bias or variability. Period effects, treatment sequence, and carryover can affect the comparison. A suitable analysis may need to reflect the repeated measurements and the design structure. The record does not report the treatment sequence, periods, washout, model terms, or analysis method, so it is not possible to determine how these considerations were handled.
The outcome population is described as all eligible, dispensed eyes. Eye-level measurements may require attention to how eyes relate to participants, because measurements from eyes belonging to the same person may not be statistically independent. This is a general methodological consideration, not evidence that the analysis did or did not account for it. The record does not explain the unit of randomization, the number of eyes analyzed, or how dependence between eyes was addressed.
What can uncertainty measures tell the reader?
Generally, a confidence interval expresses uncertainty around an estimated effect under a stated statistical method. The interval’s location describes values compatible with the data and assumptions, while its width gives information about precision. A narrow interval is more precise than a wide one, though precision alone does not determine clinical importance. The record reports no confidence interval or standard error for the primary outcome. Thus, neither precision nor compatibility with a range of possible effects can be evaluated.
A hypothesis test commonly compares data with a null hypothesis under an analysis model. Its p-value depends on the observed data and assumptions; it does not measure the probability that a treatment is effective, and it does not quantify the size of an effect. The record gives no p-value or test specification. It also does not report whether any adjustment was made for testing outcomes at more than one occasion or across multiple outcomes.
How should planning calculations be read?
General sample-size planning asks how many participants per arm would be needed under assumptions about the effect to detect, outcome variability, allocation, and statistical error rates. Such a calculation is a planning illustration, not an observed result. The stated planning assumptions use a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect expressed as a stated fraction of the observed effect. Any resulting sample-size illustration should not be described as observed power. The record does not report the trial’s own sample-size justification, and no numerical planning results are stated in the registry record.
More broadly, sample-size calculations depend on the assumptions used. If an assumed effect differs from the effect that would be relevant for a future study, the planning result may not fit that study’s purpose. A fraction of an observed effect is a way to explore alternative planning targets, not evidence that an effect of that size was clinically meaningful or reliably estimated. Since the record does not report the observed effect or its uncertainty, the basis and stability of such an effect cannot be assessed from the registry record.
Statistical interpretation therefore requires more than knowing the outcome name and the type of summary statistic. The analysis population, model, comparison definition, missing-data handling, and numerical estimates all affect what the result means. Those elements are not reported in the registry record, and the completed status does not fill those gaps.
10. Multiplicity, Missing Data and Analysis Populations
The primary visual-acuity description includes more than one assessment occasion: dispensing and one-week follow-up. The registry record does not state whether each occasion was treated as a separate primary comparison, whether one was designated as the principal occasion, or whether the results were combined. It notes that the primary outcome has several categories or time points and was not reduced to one comparison. The record therefore does not support a single overall primary estimate.
Multiplicity arises generally when several statistical comparisons are made. Testing multiple outcomes or occasions can increase the chance of at least one apparently notable result under a set of null hypotheses. Methods such as prespecified outcome hierarchies or adjustments can address this issue, but the registry record does not report a multiplicity strategy, analysis plan, or p-values. It lists slit lamp findings and comfort as secondary outcomes; numerical results for these outcomes are not reported in the registry record.
The primary population is described as all eligible, dispensed eyes. The record does not give an analysis population definition beyond that description or explain whether all eligible, dispensed eyes contributed to every outcome. It does not report exclusions, missing visual-acuity observations, reasons for missingness, or a method for handling missing data. It is therefore not possible to assess whether missingness could have affected the reported comparison.
The registry record lists zero analyses. It does not report an intention-to-treat analysis, a per-protocol analysis, or another named analysis population. These absent details limit assessment of how randomization, dispensing, follow-up, and outcome availability were connected in the analysis.
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 |
|---|---|---|---|
| Air Optix Aqua | 0 | 66 | 0.0% |
| Test Lens | 0 | 66 | 0.0% |
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 |
|---|---|
| Air Optix Aqua | 0 of 66 |
| Test Lens | 0 of 66 |
The adverse-event entries list Air Optix Aqua and Test Lens separately. For each listed group, the record gives 66 at risk, zero serious adverse events, and zero other adverse events. These counts describe what was entered in the registry record for the groups; they do not supply event descriptions or follow-up details.
The deaths field is null for both groups. Null is not the same as a reported count of zero, so deaths should be described as not reported in the registry record rather than absent. The record does not give definitions of serious or other adverse events, the collection period, the method of ascertainment, or information about completeness of safety reporting.
Because the study is identified as a crossover, the group entries should not be added to infer the number of distinct participants. The record does not explain whether the at-risk counts represent participants, eyes, or another analysis unit, nor how exposure across periods was counted. The entries are limited safety summaries and should not be interpreted as a comprehensive account of all possible adverse events or as evidence of comparative safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed randomized, single-masked crossover study was registered to compare an investigational silicone hydrogel contact lens with Air Optix Aqua. Its primary outcome was distance high-contrast visual acuity in logMAR at dispensing and one-week follow-up. The record also lists slit lamp findings and comfort as secondary outcomes. These registry entries define the study question and planned areas of assessment.
They do not establish what the study found. No least-squares means, standard deviations, treatment contrasts, confidence intervals, or p-values for visual acuity are reported. There are also no numerical secondary outcome results in the record. Without estimates and their uncertainty, it is not possible to describe the size, direction, or precision of a difference between the lenses, or to assess whether the result was consistent across assessment occasions.
The term crossover identifies a design category but does not provide the details needed to evaluate its execution. Treatment order, period structure, washout, and the analysis of repeated observations are not reported. Similarly, single masking is recorded without identifying who was masked. The study’s completion status does not resolve these questions or substitute for results.
The safety entries report zero serious and zero other adverse events in each listed group. The deaths fields are null, which means that deaths are not reported in the registry record, rather than affirmatively reported as zero. The safety information lacks event definitions and follow-up details, so it should be read narrowly as a registry summary.
In general, a study result is interpreted by considering the estimated effect, its precision, the analysis population, and the design assumptions. Here, those numerical and methodological details are largely absent. The record supports describing what was evaluated, but not a conclusion that one lens performed better, worse, or similarly to the other.
13. Why This Trial Matters Statistically
This study illustrates why design labels and outcome definitions are only part of a statistical assessment. Randomization, masking, and a crossover structure describe important features of how a comparison was intended to be made. The endpoint description adds the measurement scale, assessment occasions, summary statistic, and target population. Together, those elements explain the intended question more clearly than a device name alone.
The crossover designation is especially relevant because it changes the structure of the comparison. In general, measurements from the same participant across treatment periods can be related, and period or carryover effects may need consideration. A valid interpretation depends on information about sequence, periods, the analysis model, and the unit of analysis. Their absence from the registry record demonstrates that knowing the design label does not reveal how the analysis addressed its assumptions.
The record also shows why completion status should be distinguished from a posted result. A study may be marked completed while numerical estimates, uncertainty measures, and analysis details are not reported in the registry record. Without them, readers cannot assess precision, compare outcomes across assessment occasions, or determine whether the reported safety counts capture the full observation period.
Finally, a continuous outcome summarized by a least-squares mean and standard deviation requires both model context and numerical results for interpretation. The statistic’s name alone cannot establish effect size or relevance. This trial is therefore statistically informative as an example of how to separate a registered research question from the evidence needed to evaluate its result.
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 central limitation for interpretation is that the registry record does not report primary or secondary outcome results. In particular, no visual-acuity estimates, standard deviations, comparisons, confidence intervals, or p-values are listed. The study is marked completed, but completion does not provide the missing numerical evidence.
The outcome description contains two assessment occasions, but the record does not specify a single comparison or explain how the occasions relate to the primary analysis. It also does not state whether the intended conclusions were occasion-specific or based on a combined analysis. This makes the precise estimand—the quantity the analysis was intended to estimate—unclear.
Important crossover details are not reported, including intervention sequence, period duration, washout, and handling of period or carryover effects. The record does not identify who was masked, how masking was implemented, the randomization unit, or how eye-level observations were related to participants in the analysis. These omissions prevent a detailed assessment of design implementation and model suitability.
The analysis population is described as all eligible, dispensed eyes, but the record does not define eligibility or dispensing, report the number of analyzed eyes, or describe exclusions and missing observations. The approach to missing data, analysis populations, and multiplicity is not reported in the registry record. The registry record lists zero analyses, which further limits assessment of how the planned outcome was evaluated.
Safety information is limited to the listed event counts. Definitions, collection procedures, follow-up coverage, and detail about events are not reported. Deaths are null rather than recorded as zero. The record also does not give the trial’s own sample-size justification. These limitations constrain what can be inferred from the registry record, regardless of the stated study objective.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of a New Silicone Hydrogel Contact Lens — NCT01309880.
- Registry record last updated 2015-02-23; status last verified 2015-02.
- Results first posted 2015-02-23.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01309880 is a completed, randomized, single-masked crossover study of a Test Lens, described as an investigational silicone hydrogel contact lens, and Air Optix Aqua, described as a Ciba Vision daily wear contact lens. Enrollment is recorded as 66; the condition is myopia, the phase is listed as NA, and the recorded start and primary completion are both 2010-12.
The primary outcome is distance high-contrast visual acuity in logMAR at dispensing and one-week follow-up, summarized as a least-squares mean with standard deviation in all eligible, dispensed eyes. Slit lamp findings and comfort are listed as secondary outcomes. The registry record lists zero analyses and does not report numerical outcome results, analysis details, or a sample-size justification.
For each listed intervention group, the record reports zero serious and zero other adverse events, with 66 at risk. Deaths are not reported in the registry record. The available information describes the study question and selected design and safety fields, but does not permit evaluation of the visual-acuity comparison.