Tecnis ZLB00 & Symfony Intraocular Lens Combination Outcomes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Tecnis ZLB00 & Symfony Intraocular Lens Combination Outcomes (NCT03771274), a na na study. The primary outcome is Binocular Uncorrected Near (40 cm) Visual Acuity..

2. Clinical Question

The registry’s background describes interest in vision at far, intermediate, and near distances and in reducing dependence on spectacles after cataract surgery. It also refers to a prior study of an extended depth of focus toric lens, but that background does not provide a control group for the present study. The present record describes an outcome evaluation, not a comparison that can establish how the combination performs relative to another lens approach.

3. Trial Design

This completed study is registered as a single-group evaluation of the Tecnis ZLB00 and Symfony intraocular lens combination. Enrollment was 39. The study began on 2018-12-07, and primary completion was recorded as 2019-10-31. The registry status is completed. Phase is listed as not applicable.

The intervention was a device combination: the Tecnis multifocal ZLB00 lens and the Symfony lens. The registry describes these as presbyopia-correcting lenses designed to improve vision at distance, intermediate, and near while reducing the need for glasses. Those are descriptions of the lenses’ intended role, not results from this study.

Allocation is listed as not applicable, masking is listed as none, and the model is single group. No separate comparator arm is described. Consequently, the record does not support a randomized between-group treatment comparison. It also does not report a protocol-level account of how participants were assigned to receive the lens combination, whether both eyes received the same approach, or how any surgical decisions were made.

The primary outcome was binocular uncorrected near visual acuity measured at 40 cm at 3 months. The secondary outcomes named in the record concern patient visual satisfaction, spectacle independence, and visual symptoms. The registry lists four outcome measures overall, but no analyses are recorded. Details about eligibility criteria, participant flow, the number contributing to each outcome, and the analytic population are not reported in the registry record.

The study’s stated purpose was to evaluate visual outcomes when an extended depth of focus lens is combined with a multifocal lens in patients undergoing routine cataract surgery, with or without astigmatism. A comparator, randomization procedure, and masking are not described as parts of the design. This means that any outcome description would need to be interpreted as evidence from the enrolled group rather than as a controlled estimate of a difference between lens strategies.

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

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 Binocular Uncorrected Near (40 cm) Visual Acuity., measured over 3 months.

The primary endpoint is binocular uncorrected near visual acuity at 40 cm, assessed at 3 months. “Binocular” means the measure concerns vision using both eyes together. “Uncorrected” indicates that the measurement is taken without wearing visual correction. The registry identifies the outcome as a continuous measure in logMAR units and specifies a mean with standard deviation as the summary form.

Near visual acuity is relevant to the study’s stated interest in vision at near distances after cataract surgery. Measuring it without correction makes the endpoint directly related to unaided near vision, while the binocular measure reflects the two-eye viewing condition rather than an individual eye considered alone. These are general descriptions of what the endpoint represents; they do not establish what participants experienced.

For a continuous outcome, a mean describes the central level of the observed measurements, while a standard deviation describes their spread. A logMAR value expresses visual acuity on a logarithmic scale. In general, visual-acuity values on this scale are interpreted with the scale’s direction in mind; the registry record does not provide a result to interpret.

The endpoint definition does not itself show whether the lens combination achieved a particular level of near vision, how variable measurements were, or how complete the measurements were at the assessment. The mean, standard deviation, and any accompanying uncertainty estimate for the primary outcome are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the outcome summary represent?

The primary outcome is continuous: binocular uncorrected near visual acuity in logMAR units. The registry specifies that it is to be summarized as a mean and standard deviation. In general, the mean describes the center of a set of measurements, while the standard deviation describes how dispersed measurements are around that center. They answer different questions: the mean concerns the measured level, and the standard deviation concerns variability among observations.

A mean and standard deviation do not, by themselves, fully describe uncertainty about the population value. A confidence interval is a general statistical tool for expressing uncertainty around an estimate under a chosen method and its assumptions. The registry record does not report a mean, standard deviation, or confidence interval for the primary outcome, so none can be interpreted for this study.

What does a single-group design allow?

In a single-group study, outcomes are observed in a group receiving the intervention without a separate comparison group described in the record. A group mean can be descriptive, if reported, but it is not a treatment contrast. Without a comparator, the study cannot estimate how outcomes would differ under another lens strategy using a between-group comparison. This general design distinction is important even when the outcome itself is measured objectively.

Allocation is listed as not applicable, masking as none, and the study model as single group. The record does not describe a randomization process or a blinded assessment procedure. It does not report further details about outcome measurement procedures, so the possibility or extent of measurement-related influences cannot be assessed from the registry record.

How should the planning illustrations be understood?

The registry describes sample-size illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. For non-time-to-event outcomes, the illustrations are expressed as participants per arm. These are planning illustrations, not the enrolled study’s design or an observed-power analysis. They do not transform this single-group study into a two-arm comparison.

Sample-size planning generally asks how many observations might be needed under specified assumptions to detect a target effect with a chosen level of power. Such a calculation depends on the effect size and variability assumptions, among other inputs. The registry’s description does not report a trial-specific sample-size justification or the protocol’s original planning assumptions. It also does not report an observed primary effect in the results, so the illustrations should not be read as evidence of the study’s ability to detect an effect.

Why can over-dispersion matter?

For count outcomes, over-dispersion means that variability exceeds what a simple model assumes. In general, using a model that underestimates variability can make uncertainty look too small. This is a general statistical concept; the primary outcome in this study is continuous, and the registry does not report an analysis of count outcomes or describe an over-dispersion assessment.

What can be inferred from the analysis record?

The record lists four outcome measures and zero analyses. That means no statistical analysis results are recorded for interpretation. It does not establish which analytic methods were planned or used outside the registry record. The statistical plan, including any model, covariate adjustment, confidence-interval method, handling of repeated or paired eye measurements, and interim analyses, is not reported in the registry record.

For general interpretation, a statistical test evaluates data relative to a specified null hypothesis and model assumptions. A confidence interval gives a way to assess uncertainty and precision. Neither substitutes for examining the design, measurement, completeness of data, and relevance of the outcome. In this record, no test results or interval estimates are reported, so those inferential concepts cannot be applied to a numerical primary result.

The registry identifies a mean and standard deviation as the primary outcome’s summary parameters, but it does not state whether the mean was calculated from all enrolled participants, only participants with an assessment, or another population. It does not report a statistical analysis plan or analysis population. Those details should not be inferred from the listed outcome definition or from the completed status.

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("Tecnis ZLB00 & Symfony IOL")
n   <- c(39)
m   <- c(0.13)
sp  <- c(0.09)
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  Tecnis ZLB00 & Symfony IOL  39  0.130  0.090  0.101  0.159

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures overall. The primary measure is binocular uncorrected near visual acuity at 40 cm at 3 months. The named secondary outcomes concern patient visual satisfaction after cataract surgery, spectacle independence, and visual symptoms. The record lists zero analyses, so it does not report results for these outcomes or explain how they were analyzed.

Multiplicity arises when several outcomes or statistical tests are considered. In general, examining multiple tests can increase the chance of finding at least one apparently notable result by chance. Statistical plans may address this through a prespecified hierarchy or adjustment, but the plan for handling multiplicity is not reported in the registry record. It is not possible to determine from the outcome list alone whether any formal adjustment was intended or used.

The record does not report the number of participants with observed data for each outcome, the amount or pattern of missing data, or how missing measurements and questionnaire responses were handled. It also does not report whether analyses used an intention-to-treat population, a per-protocol population, or another analysis population. The enrolled number is 39, but enrollment alone does not establish how many contributed data at the 3-month assessment.

Because no analyses are recorded, there are no reported sensitivity analyses or comparisons of results under different missing-data assumptions. These omissions limit assessment of whether the reported outcomes, if available elsewhere, represent all enrolled participants or a subset. The registry record does not describe a statistical plan for multiplicity, missing data, or analysis populations.

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 3% reporting threshold.

The registry’s safety figures list 0 serious adverse events among 39 participants at risk in the Tecnis ZLB00 and Symfony IOL group. It also lists 0 other adverse events among 39 at risk and 0 deaths. No serious adverse event terms are listed.

These figures describe the counts recorded in the registry. They should not be read as proof that the intervention has no safety risks. A count of zero in a study group does not establish that events could not occur, and the record does not give details about the duration or completeness of safety monitoring, event definitions, or the process for collecting events. Those details are not reported in the registry record.

The at-risk count is the denominator stated for the group in the safety record. The registry does not provide further information about safety follow-up or whether the same participants contributed to every outcome assessment. The counts also do not provide a comparative safety estimate, because no separate comparator group is described. Thus, the safety figures are best read as the recorded event counts for this group, not as a comparison or a definitive characterization of risk.

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

The registry record shows that a completed study evaluated a combination of Tecnis ZLB00 multifocal and Symfony extended depth of focus intraocular lenses. It enrolled 39 participants and specified binocular uncorrected near visual acuity at 40 cm at 3 months as its primary outcome. It also named patient satisfaction, spectacle independence, and visual symptoms as secondary outcomes.

The record does not report numerical results for the primary or secondary outcomes, and it lists no analyses. It therefore does not show the observed near visual acuity, the variability of measurements, the level of satisfaction, or the degree of spectacle independence. It also does not provide statistical estimates of precision or tests of hypotheses. Naming an outcome is not the same as reporting its result.

The design does not include a separate comparator group in the registry description. Therefore, even if a group outcome were available, it would describe observations in that group rather than establish a difference from another lens approach. This is a general interpretation of single-group evidence, not a statement about an unreported outcome.

The safety record lists zero serious adverse events, zero other adverse events, and zero deaths, with 39 participants at risk. These recorded counts are informative as registry entries, but they do not establish that no safety concerns could arise in other settings or with different follow-up. The record does not report the safety-monitoring details needed to assess completeness.

In short, the record documents the study question, intervention, design, outcome definitions, enrollment, and recorded safety counts. It does not report the outcome findings needed to judge the measured visual results or their precision. It also does not support a controlled comparison or a conclusion about relative performance.

14. Why This Trial Matters Statistically

This trial matters statistically because it illustrates the difference between a clearly defined outcome and a reported result. The primary measure is specific about the visual task, viewing condition, distance, scale, and assessment time: binocular uncorrected near visual acuity at 40 cm, in logMAR, at 3 months. Yet the registry record does not report the numerical result or an analysis. Readers therefore cannot assess the observed level, spread, or precision of the outcome from the record.

It also illustrates why design and analysis have to be interpreted together. The study is single group, with allocation listed as not applicable and no comparator described. This design can be used to describe outcomes in the enrolled group, but it does not supply a controlled estimate of how the outcome differs under another approach. The stated purpose and the lens descriptions do not replace a comparison.

The record names multiple outcomes, including visual acuity, satisfaction, spectacle independence, and visual symptoms. Without analyses, a statistical plan, or missing-data details, it is not possible to assess how those outcomes were prioritized or interpreted together. This highlights the value of transparent reporting of analytic methods, outcome results, and the populations included in each analysis.

Finally, the safety record gives zero recorded events in the listed categories, but those counts need context about monitoring and follow-up to support a fuller interpretation. The available information is therefore useful for identifying what the study set out to assess and what the registry recorded, while also showing why design details and complete results are necessary for statistical conclusions.

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 trial-specific limitation in the registry record is that the primary outcome result is not reported. Although the measure and assessment time are defined, the record gives no mean, standard deviation, or uncertainty estimate. It also lists no analyses. The visual outcome cannot therefore be quantified or assessed for precision from the registry record.

The single-group design has no separate comparator described. As a result, the record does not support a controlled comparison of this lens combination with another intervention. Allocation is listed as not applicable, and masking is listed as none. Further detail about outcome assessment procedures is not reported in the registry record.

The enrollment was 39, but the record does not state how many participants contributed measurements at the primary assessment or at each secondary outcome. Participant flow, missing-data handling, eligibility details, and analysis populations are not reported. This limits evaluation of the completeness and representativeness of any outcome assessment.

The registry names secondary outcomes but does not report their results, detailed measurement methods, or an approach to multiplicity. It does not report a statistical analysis plan, sample-size justification, covariate adjustment, or interim analyses. The sample-size assumptions described for planning illustrations are not a substitute for a trial-specific design rationale, and the illustrations should not be treated as observed power.

The safety counts are recorded without details about monitoring duration, event definitions, or completeness of ascertainment. These limitations concern what can be assessed from the registry record; they do not establish that unreported methods or information were absent from other study materials.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Tecnis ZLB00 & Symfony Intraocular Lens Combination Outcomes — NCT03771274.
• Registry record last updated 2020-08-10; status last verified 2020-08.
• Results first posted 2020-08-10.
• 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

NCT03771274 is a completed single-group study of the Tecnis ZLB00 multifocal and Symfony extended depth of focus intraocular lens combination. Enrollment was 39. The primary outcome was binocular uncorrected near visual acuity at 40 cm, measured in logMAR at 3 months and specified for summary as a mean with standard deviation.

The registry lists patient visual satisfaction, spectacle independence, and visual symptoms as secondary outcomes. It records zero analyses. The primary and secondary outcome results are not reported in the registry record. No separate comparator group is described; allocation is listed as not applicable and masking as none.

The safety record lists 0 serious adverse events, 0 other adverse events, and 0 deaths among 39 participants at risk. Further details about outcome completeness, missing data, analysis populations, and statistical methods are not reported in the registry record.