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 Spectacles Lens in Concussed Kids (NCT03123822), a randomized na study. The primary outcome is Convergence Insufficiency Symptom Survey.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03123822 |
| Phase | NA |
| Condition | Concussion, Mild, Convergence Insufficiency, Accommodation; Insufficiency |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 10 |
| Arms in the primary outcome | 3 |
| Lead sponsor | University of Alabama at Birmingham |
| Results posted | Yes |
2. Clinical Question
Population
Children with prolonged visual symptoms due to concussion were the intended population. The registry states that all participants met the study criteria, but the detailed eligibility criteria and the number screened or excluded are not reported in the registry record. The listed conditions include mild concussion, convergence insufficiency, and accommodation insufficiency.
Intervention
One arm received Eyezen, described as commercially available, low-powered progressive addition lenses with an anti-glare coating, to be worn during all waking hours. The trial also included single vision glasses with an anti-glare coating as an active option rather than leaving the comparison to routine care without glasses.
Comparator
The comparator was single vision glasses prescribed to correct distance refractive error, to be worn during all waking hours. A second comparison arm used the same general type of single vision glasses with an anti-glare coating. The registry describes the study as randomized, with three parallel arms and triple masking.
Primary question
The primary question was whether the mean Convergence Insufficiency Symptom Survey score differed among the lens options. The survey measures convergence insufficiency symptoms on a scale from 0 (least) to 60 (worst). The registry describes assessment up to 12 months. It does not report a specific between-arm statistical test or analysis result, so the posted arm summaries alone do not establish whether observed score differences reflect a reproducible treatment effect.
3. Trial Design
The registry describes a randomized, triple-masked, parallel-group study with three glasses arms. Randomization is intended to assign participants to treatment groups by chance, while masking is intended to limit the influence of knowledge about assignment on aspects of trial conduct or assessment. The registry does not describe who was masked, how masking was maintained, or the randomization procedure. Those details are not reported in the registry record.
The three groups were single vision glasses, single vision glasses with an anti-glare coating, and Eyezen. The first option was described as typical glasses prescribed to correct only distance refractive error. The anti-glare arm added that coating to the distance prescription. Eyezen was described as a commercially available, low-powered progressive addition lens with anti-glare coating. All were intended to be worn during all waking hours. Thus, the comparisons concern different lens and coating approaches, not glasses versus no glasses.
The registry lists an enrollment of 10, while the posted primary-outcome summaries show one participant in each of the three arms. The record does not explain the relationship between the enrollment figure and the participants contributing to these outcome summaries. The study status is terminated. Its start date is 2017-10-31, and its primary completion date is 2021-10-01; the reason for termination is not reported in the registry record.
The planned primary outcome was the Convergence Insufficiency Symptom Survey score, with assessment described as occurring up to 12 months. A secondary outcome is listed as convergence breaking point at near, measured with base out prism. The registry does not describe the timing of each reported score, adherence to glasses use, or how the arm summaries were formed across the stated follow-up period.
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 | Single Vision Glasses | Single Vision Glasses With Anti-glare Coating | Eyezen |
|---|---|---|---|
| STARTED | 1 | 1 | 3 |
| COMPLETED | 1 | 1 | 3 |
| NOT COMPLETED | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: All participants met the criteria of the study
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: It is not different from the assignment in participant flow
| Characteristic | Unit | Single Vision Glasses | Single Vision Glasses With Anti-glare Coating | Eyezen | Total |
|---|---|---|---|---|---|
| Participants analysed | 1 | 1 | 3 | 5 | |
| Age, Categorical: <=18 years | Participants | 1 | 1 | 3 | 5 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 | 0 |
| Age, Continuous | years | 17 | 14 | 16 (14 to 17) | 16 (14 to 17) |
| Sex: Female, Male: Female | Participants | 1 | 1 | 2 | 4 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 1 | 1 |
| Race and Ethnicity Not Collected | Participants | — | — | — | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Convergence Insufficiency Symptom Survey, measured over Assessed up to 12 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the Convergence Insufficiency Symptom Survey. It is a continuous symptom measure: participants’ scores can take values on a scale from 0 (least) to 60 (worst). The registry describes the survey as quantifying symptoms of convergence insufficiency and states that it has been used as a gauge in previous research and study groups. The endpoint is assessed up to 12 months, although the specific visit or visits represented by the posted arm values are not reported in the registry record.
A symptom score is useful because it expresses the outcome on a common scale, rather than reducing the assessment to a simple yes-or-no classification. For a continuous measure, group means can describe the central level of scores, while measures of dispersion describe how much participants’ scores vary. In general, a lower score on this scale corresponds to fewer or less severe symptoms. That direction helps readers understand the scale, but a group mean is not itself a treatment comparison and does not show how precisely an effect has been estimated.
The record reports mean scores and standard deviations for the arms. Because each posted arm summary has one participant, these summaries provide very little information about variation between participants. The registry does not report a prespecified clinically meaningful change or threshold for interpreting score differences. It also does not report a detailed endpoint scoring or missing-item procedure.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary-outcome summaries are mean scores of 29.0 for Single Vision Glasses, 22.0 for Single Vision Glasses With Anti-glare Coating, and 14.0 for Eyezen. Each arm has a reported sample size of 1.0, and each reported standard deviation is 0.0. On the survey’s stated scale, lower scores represent fewer symptoms. The arm values therefore describe the scores recorded for the very small number of participants represented in these summaries; they do not establish a reliable ordering of treatment effects in the broader population.
A standard deviation of 0.0 in a group with one participant should not be read as evidence that participants assigned to that option would have identical scores. With only one score, there is no meaningful estimate of variation among participants in that group. Similarly, the reported means do not permit a stable estimate of the uncertainty around a group mean. The registry does not post confidence intervals, hypothesis tests, or other inferential comparisons for the primary endpoint.
The registry lists an enrollment of 10, but the outcome summaries report one participant in each arm. It does not explain why the outcome summaries include those numbers of participants, whether other enrolled participants lacked endpoint data, or how missing outcome data were handled. This difference in the reported enrollment and outcome counts limits interpretation of who is represented by the posted scores. It cannot be resolved by assuming a reason that the registry does not state.
The study is marked terminated, but the reason for termination is not reported in the registry record. The status alone does not identify why the study ended or whether the posted summaries were intended as a final analysis. The record lists zero analyses and does not provide a statistical test of the primary outcome. Consequently, the arm means are descriptive results, not evidence from a reported inferential comparison. No conclusion about statistical significance can be drawn from them.
These limitations are especially important when comparing three arms. A difference in observed means can arise from actual differences between options, from individual variation, or from chance; with one observation in each arm, the posted data cannot distinguish these explanations. The result summaries are therefore best understood as sparse descriptive information. They do not quantify the precision of a treatment contrast, and they do not establish whether any observed separation would persist in a larger group.
The registry also lists a secondary outcome, convergence breaking point at near using base out prism, but no secondary results or analysis are included in the record. The primary score values do not answer that secondary question. Overall, the posted results characterize three individual scores on the symptom survey; they do not provide a dependable estimate of comparative effectiveness, uncertainty, or the size of any population-level effect.
9. Statistical Methods Explained
The registry identifies a continuous primary outcome and reports the arm results as means with standard deviations. The following statistical concepts explain how such summaries are generally interpreted; they are not a description of an analysis plan reported for this study. The registry does not report the statistical methods used to compare arms.
What does a mean describe?
For a continuous measure, a mean summarizes the center of the observed scores in a group. It can be useful for comparing groups when there are enough participants and when the summaries correspond to comparable assessments. A mean alone does not show the spread of scores, the uncertainty around the mean, or whether an observed difference is compatible with chance variation. The registry’s three posted means describe the observed arm scores, but the group size of one in each arm prevents meaningful estimation of within-arm variability.
The standard deviation describes how spread out observations are around a group mean. In general, it is used to communicate participant-to-participant variation, not the precision of a mean by itself. When only one observation is present, a between-participant spread cannot be assessed. The reported standard deviation of 0.0 for each arm therefore should not be interpreted as proof of no variability in the population. The registry does not report confidence intervals around the arm means or any estimate of uncertainty for comparisons.
What would an arm comparison require?
A comparative analysis would need to estimate how scores differ between assigned groups and describe the uncertainty in those estimates. A confidence interval is a range calculated using a statistical procedure to express uncertainty about an estimated quantity. In general, wider intervals indicate less precision, and narrower intervals indicate greater precision under the assumptions of that procedure. No confidence intervals or direct arm-comparison estimates are reported for this endpoint. The means alone cannot substitute for them.
Comparisons also depend on the analysis approach. For example, an analysis might compare follow-up scores directly or account for baseline scores, but the registry does not report which approach was planned or used. Baseline symptom scores, covariate adjustments, treatment adherence, and the exact follow-up time represented in the summaries are not reported in the registry record. It would be inappropriate to infer an adjusted result or to treat the posted arm means as an adjusted treatment contrast.
Why does the small outcome count matter?
Small samples produce limited information about both the center and spread of an outcome. With one participant per arm in the posted summaries, an individual score determines that arm’s reported mean. The summaries cannot reveal how much scores might differ across other participants assigned to the same option. General statistical procedures that estimate standard errors or confidence intervals rely on assumptions and information that are not available from these arm summaries alone. The registry reports no inferential analysis to address this limitation.
Random allocation is a design feature, not a guarantee that the observed groups are comparable in every respect, particularly when the outcome summaries contain very few participants. In a sufficiently sized randomized study, randomization supports a fair comparison on average. It does not make a sparse set of observations precise, nor does it identify whether missing outcome data or other features affected the posted results. The registry record does not report baseline characteristics or an analysis population definition.
What is the role of planning illustrations?
Sample-size planning asks how many participants may be needed to detect a specified effect under stated assumptions about the statistical test, allocation, significance level, and outcome variability. A planning illustration based on an observed effect is conditional on that effect and those assumptions. It is not an estimate of the probability that the original study would have found a result, and it is not observed power. With only one participant represented in each posted arm summary, an observed separation is highly unstable as a basis for planning. Any such illustration should therefore be read as a hypothetical planning exercise, not as a confirmatory result or a reconstruction of the study’s original design.
The registry record does not report the trial’s own sample-size justification, target effect, variance assumption, or power calculation. The record includes no reported statistical test for the primary endpoint, no p-value, and no confidence interval. These omissions mean that the posted data support a descriptive reading of the observed scores, not a claim that the trial demonstrated a statistically reliable difference.
What can the reported scale tell readers?
The score ranges from 0 (least) to 60 (worst), so its direction has a direct descriptive interpretation: lower values correspond to fewer symptoms on the survey. The exact clinical meaning of a particular difference depends on context, including measurement reliability, meaningful-change criteria, follow-up timing, and the participants’ baseline scores. Those details are not reported in the registry record. The numerical scale therefore helps readers orient themselves, but it does not by itself establish whether a given difference is important or attributable to the glasses option.
Overall, the statistical information reported for the primary endpoint consists of arm-level means, standard deviations, and sample sizes. The record does not state how the data were analyzed beyond those summaries. General statistical principles can explain why additional information is necessary, but they cannot fill in the study’s unreported analysis methods or turn the descriptive values into an inferential result.
10. Multiplicity, Missing Data and Analysis Populations
The study includes three randomized arms and lists a primary symptom-survey outcome and a secondary convergence-breaking-point outcome. Comparing multiple arms or considering more than one outcome can create multiplicity: when several statistical questions are tested, the chance of obtaining an apparently unusual result by chance can increase. In general, a prespecified testing strategy can address this issue, for example by defining a primary comparison or adjusting interpretation across multiple tests. The registry does not report a multiplicity plan, a hierarchy of comparisons, or any statistical tests. No adjustment method should be assumed.
The registry lists one secondary outcome and reports two outcome measures in total, but it does not post results for the secondary outcome. Its analysis is therefore not available for interpretation. The record does not specify whether the three arms were to be compared pairwise, whether one arm was the primary comparator for the others, or whether the analysis was intended to test an overall difference among all arms.
Missing-data handling is also not reported in the registry record. The registry lists an enrollment of 10, while the primary-outcome summaries show one participant per arm. The record does not state whether participants lacked endpoint measurements, withdrew, were excluded from the outcome summaries, or were handled in another way. These are possible explanations in general, not explanations established for this study. There is no reported imputation method or sensitivity analysis.
The analysis population is not described. Randomization does not by itself tell a reader whether the reported results include all randomized participants, only those with observed outcomes, or another group. The registry does not state whether an intention-to-treat or per-protocol approach was used. Without that information, the population represented by the arm summaries cannot be fully characterized.
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 |
|---|---|---|---|
| Single Vision Glasses | 0 | 1 | 0.0% |
| Single Vision Glasses With Anti-glare Coating | 0 | 1 | 0.0% |
| Eyezen | 0 | 3 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Single Vision Glasses | 0 of 1 |
| Single Vision Glasses With Anti-glare Coating | 0 of 1 |
| Eyezen | 0 of 3 |
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 |
|---|---|
| Single Vision Glasses | 0 of 1 |
| Single Vision Glasses With Anti-glare Coating | 0 of 1 |
| Eyezen | 0 of 3 |
The registry’s adverse-event figures report zero serious adverse events in each arm and zero deaths in each arm. The numbers at risk for serious adverse events are 1 in the Single Vision Glasses arm, 1 in the Single Vision Glasses With Anti-glare Coating arm, and 3 in the Eyezen arm. The numbers at risk for other adverse events are also 1, 1, and 3, respectively; the reported number affected by other adverse events is zero in each arm.
These counts describe what was recorded for the small groups represented in the safety data. A count of zero means that no event of that category was reported among the listed participants; it does not establish that the risk is absent or that the options have equivalent safety. With so few participants, uncommon events and differences in event rates cannot be assessed reliably. The registry lists no serious adverse-event terms. It does not provide further details about the observation period, event collection procedures, or how adverse events were attributed to an intervention. The figures are descriptive and should not be generalized beyond the participants represented in the record.
12. What the Result Does, and Does Not, Mean
The posted results show three mean scores on the Convergence Insufficiency Symptom Survey: 29.0 for Single Vision Glasses, 22.0 for Single Vision Glasses With Anti-glare Coating, and 14.0 for Eyezen. The survey’s scale runs from 0 (least) to 60 (worst), so the lower observed scores correspond to fewer symptoms on the scale. Each arm summary represents one participant. These values describe those observations; they do not demonstrate that one lens option generally produces a lower symptom score than another.
The findings do not provide a precise estimate of a population-level treatment effect. There are no reported confidence intervals or hypothesis tests for the primary endpoint, and the standard deviations reported as 0.0 cannot estimate participant variability when each arm has one observation. The registry also does not state a clinically meaningful score difference. Consequently, the posted means cannot establish the clinical importance of the observed score pattern.
The record does not report the reason the trial was terminated, the statistical analysis plan, a sample-size justification, missing-data methods, or the analysis population. It also does not provide results for the listed secondary outcome. These gaps restrict interpretation of how the observations were selected, how complete the follow-up was, and what comparisons were intended.
In general, a randomized design can support comparisons when the study has adequate information and the analysis is clearly specified. Randomization and masking are listed for this trial, but those design features cannot compensate for sparse outcome summaries or unreported methods. Nor do descriptive scores establish that an intervention works or does not work. They show only the symptom scores recorded for the participants included in the posted summaries. The registry record does not support a firm comparative conclusion among the three glasses options.
13. Why This Trial Matters Statistically
This trial is statistically instructive because it pairs a randomized, triple-masked, parallel design with very sparse posted primary-outcome summaries. Those features illustrate why design labels and result precision answer different questions. Randomization describes how assignment was intended to occur; masking describes efforts to limit knowledge of assignment. Neither label indicates how much information the final outcome data contain.
The primary outcome is a continuous symptom score, for which means and standard deviations are familiar descriptive summaries. But the usefulness of those summaries depends on the number of observations. With one participant represented in each arm, a mean is simply the observed score for that participant, and a standard deviation cannot describe variation among participants. The values can be reported exactly while still offering little basis for judging reproducibility or precision.
The registry also distinguishes planned scope from posted results. It describes three options, a primary survey outcome, a secondary outcome, and an enrollment of 10. The posted primary summaries include one participant per arm, and the registry lists no analyses. This makes transparent reporting of participant flow, outcome availability, analysis methods, and reasons for termination particularly important. Those details are not reported in the registry record.
For clinical researchers and biostatisticians, the central lesson is that descriptive arm values should not be mistaken for an inferential comparison. Without an analysis plan, uncertainty estimates, and an account of the outcome population, apparent differences remain difficult to interpret. The record provides a useful example of the limits of what can be learned from registry summaries, even when the intervention arms and outcome scale are described.
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 posted primary-outcome summaries include one participant in each arm, despite a registry enrollment of 10. The record does not explain this difference or identify how many participants had available primary endpoint data. The small outcome counts sharply limit interpretation of arm-level means and prevent the standard deviations from reflecting participant-to-participant variation.
The study is marked terminated, but the reason for termination is not reported in the registry record. The registry does not clarify whether termination affected recruitment, follow-up, or the availability of the posted outcome data. The listed primary completion date is 2021-10-01, but the exact assessment time represented by each score is not stated; the outcome timeframe is described only as assessed up to 12 months.
Eligibility criteria are not detailed beyond the statement that all participants met the study criteria and the listed conditions. Baseline symptom scores, participant characteristics, adherence to wearing the glasses, and treatment discontinuations are not reported. The record does not describe who was masked, the randomization method, or the analysis population. These omissions make it difficult to assess the comparability and representativeness of the participants included in the outcome summaries.
No primary-outcome comparison, confidence interval, p-value, missing-data approach, or multiplicity plan is reported. The registry lists a secondary outcome but provides no result for it. It also does not report a clinically meaningful score threshold or the trial’s sample-size justification. These limitations leave the arm values as descriptive observations rather than a basis for a precise or generalizable comparison.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Spectacles Lens in Concussed Kids — NCT03123822.
- Registry record last updated 2022-06-23; status last verified 2022-05.
- Results first posted 2022-06-23.
- 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.
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18. Record Summary
NCT03123822 is a randomized, triple-masked, parallel study sponsored by the University of Alabama at Birmingham. It compared single vision glasses, single vision glasses with an anti-glare coating, and Eyezen for children with prolonged visual symptoms after concussion. The registry lists an enrollment of 10 and a terminated status.
The primary outcome was the Convergence Insufficiency Symptom Survey score, assessed up to 12 months on a scale from 0 (least) to 60 (worst). Posted means were 29.0, 22.0, and 14.0, with one participant represented in each arm. The registry reports no analyses and no inferential comparison. A secondary outcome is listed, but no result is posted. The reason for termination and the relationship between enrollment and the outcome counts are not reported in the registry record.