A Clinical Outcome Study of Two Multifocal Intraocular Lenses (IOL) in Cataract Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Clinical Outcome Study of Two Multifocal Intraocular Lenses (IOL) in Cataract Patients (NCT01684007), a randomized na study. The primary outcome is Binocular Distance Corrected Visual Acuity (logMAR) - Intermediate (60 cm).

2. Clinical Question

The study also posted binocular distance-corrected visual acuity at near distance, measured at 40 cm, for the same time point. Its comparison offers another view of visual acuity, but it is a secondary outcome rather than the primary question. The registry describes the study purpose as comparing bilateral +2.5 D implantation with the combination of +2.5 D in the dominant eye and +3.0 D in the fellow eye. The central interpretive issue is therefore the difference between these two lens-placement strategies at the posted follow-up, not a comparison with no treatment or with a different type of lens.

3. Trial Design

The registry describes NCT01684007 as a randomized, single-masked, parallel-group study of multifocal intraocular lenses in cataract patients. It was listed as completed, with enrollment of 112. The registry records the study start as 2012-11 and primary completion as 2013-08. The sponsor was Alcon Research, and the phase was listed as NA.

Participants were assigned to one of two implantation strategies. In the Bilateral group, the AcrySof® IQ ReSTOR® +2.5 D lens was implanted in both eyes. In the Contralateral group, the +2.5 D lens was implanted in the dominant eye and the +3.0 D lens in the fellow eye. The registry describes randomization in relation to the choice of lens in the fellow eye. Further details about the randomization sequence, allocation concealment, and the person or people masked are not reported in the registry record.

The primary outcome was binocular distance-corrected visual acuity at intermediate distance, tested at 60 cm. The recorded time point was Day 90 from second-eye implantation. The secondary outcome was binocular distance-corrected visual acuity at near distance, tested at 40 cm, at the same time point. Both outcomes were continuous measures expressed in logMAR, with lower values denoting better visual acuity.

The primary analysis population is described as all subjects with both eyes implanted. The registry does not report a detailed participant flow, reasons for any difference between enrollment and the groups contributing outcome results, or the handling of participants without an outcome measurement. The original sample-size assumptions and any prespecified statistical analysis plan are not reported in the registry record. The posted group summaries and simple unadjusted recalculations can describe the recorded results, but they do not establish what analyses were prespecified or whether additional analyses were conducted outside the registry.

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: Of the 112 subjects enrolled, 9 were discontinued prior to randomization as screen failures. This reporting group includes all implanted subjects (103).

Overall Study

Analysis population for the primary outcome, as defined in the registry: This analysis population includes all subjects with both eyes implanted.

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: This analysis population includes all implanted subjects.

6. Primary Endpoint

The registry lists the primary outcome as Binocular Distance Corrected Visual Acuity (logMAR) - Intermediate (60 cm), measured over Day 90 from second eye implantation.

The primary endpoint is binocular distance-corrected visual acuity at intermediate distance, measured at 60 cm on Day 90 from second-eye implantation. Binocular testing measures vision with both eyes together. The registry describes testing with manifest refraction adjusted for optical infinity, using a hand-held, 100% contrast ETDRS chart set at 60 cm on a nearpoint rod. The recorded outcome is in logMAR, or logarithm of the minimum angle of resolution. The registry notes that 0.1 logMAR corresponds to 5 letters, or 1 line, on the ETDRS chart, and that a lower logMAR value denotes better visual acuity.

This endpoint addresses intermediate-distance vision under the specified binocular test conditions. It is a continuous measure, so the posted results describe group means and standard deviations rather than only counts above or below a threshold. Comparing the means gives a direct summary of the average recorded acuity in each group. The standard deviations describe variation among the participants contributing results.

Visual acuity is used to assess a clinical outcome associated with the two lens-placement strategies. The test distance, binocular assessment, correction method, chart, and timing define what the measure represents; results should be interpreted in that context. The endpoint does not by itself describe every aspect of vision or patient experience. Other outcomes, including patient-reported experience and functional performance, are not reported in the registry record.

7. Results Posted in the Registry

• Contralateral: mean 0.09 versus 0.13 on control; difference -0.04 (95% CI -0.09 to 0.01), standardized effect d = -0.28; z-test p = 0.149.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Binocular Distance Corrected Visual Acuity (logMAR) - Near (40 cm)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Contralateral: mean 0.10 versus 0.26 on control; difference -0.16 (95% CI -0.22 to -0.10), standardized effect d = -1.09; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Contralateral than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The registry posts one secondary endpoint: binocular distance-corrected visual acuity at near distance, measured at 40 cm on Day 90 from second-eye implantation. Its group means and unadjusted comparison point in the same direction as the primary endpoint on the logMAR scale, where lower values denote better visual acuity. The secondary comparison also has an interval that does not include zero and an unadjusted p-value of <0.001. The outcome is related to the primary question because both assess binocular visual acuity, but it measures acuity at a different viewing distance.

The difference in statistical evidence across distances is a reason to keep the outcomes distinct rather than combine them into one claim. The primary endpoint remains the principal result for the study's stated primary question. The secondary result adds information about the posted near-vision measure, but it does not change what the primary comparison shows. The registry does not provide a composite outcome combining intermediate and near acuity, nor does it report a prespecified hierarchy that would define how a secondary finding should affect interpretation of the primary result.

Unadjusted secondary results generally carry less weight when several outcomes or tests may have been examined, because the chance of at least one apparently notable result can increase as the number of tests increases. This is a general statistical consideration, not a claim that a particular set of additional tests was conducted in this trial. The record lists two outcome measures and does not report a multiplicity adjustment, a testing sequence, or a broader set of analyses. The secondary result should therefore be treated as supportive descriptive evidence, with its inferential strength qualified by the absence of reported multiplicity procedures.

The registry lists no reported analyses for the outcomes. Consequently, the posted comparisons should be understood as unadjusted recalculations from summary statistics rather than a detailed account of an analysis plan. The record does not say whether the secondary outcome was prespecified, whether other secondary or exploratory outcomes were considered, or how results were selected for posting. Those omissions prevent a firm assessment of the full multiplicity burden.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Binocular Distance Corrected Visual Acuity (logMAR) - Near (40 cm)

9. Statistical Interpretation

10. Statistical Methods Explained

The registry posts continuous outcomes as means and standard deviations. A mean is the arithmetic average of the measured values in a group. A standard deviation describes how dispersed the individual measurements are around that average: a larger value indicates greater variability among participants. These summaries are useful for describing group results, but they do not show the full distribution of individual outcomes or reveal whether the data contain unusual values.

What does a mean difference represent?

The unadjusted mean difference compares the two group means by subtracting the Bilateral mean from the Contralateral mean. A negative value indicates a lower mean in the Contralateral group. For these outcomes, lower logMAR denotes better visual acuity, so the direction of the difference can be described using that scale. The contrast is unadjusted: it does not account for other participant characteristics or covariates. No adjusted analysis is reported in the registry record.

The posted recalculations use the group summary statistics to estimate the mean difference and its interval. They are simple unadjusted calculations, not evidence that the registry's sponsor conducted or endorsed a particular model. The registry lists no reported analyses for these outcome measures. Where a sponsor analysis is available, it takes precedence over a simple recalculation; no discrepancy is identified in this record.

How should the interval be read?

A confidence interval expresses uncertainty about an estimated quantity. In general, it gives a range of values compatible with the observed data under the calculation method and its assumptions. A narrower interval indicates greater precision, while a wider interval indicates more uncertainty. For a difference in means, an interval that includes zero is compatible with no difference; an interval entirely on one side of zero is not compatible with zero under that interval procedure. The registry does not state the confidence level or detailed interval method, so interpretation should focus on the posted interval limits rather than assume unreported procedural details.

What does the p-value add?

In general, a p-value describes how unusual data at least as discrepant as those observed would be under a specified null model. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. The posted p-values are unadjusted. The primary comparison has an unadjusted p-value of 0.149; the secondary comparison has an unadjusted p-value of <0.001. The registry does not report whether these tests were prespecified, what assumptions were used for the original sponsor analysis, or whether other analyses were performed outside the record.

Why can variability matter?

General statistical explanation: when individual measurements vary substantially, the group mean is estimated less precisely for a given number of participants. The standard deviation therefore helps readers understand how much participant-level variation accompanies the average. In group comparisons, precision also depends on how many participants contribute data. The primary endpoint summaries include 53 participants in the Bilateral group and 50 in the Contralateral group. The registry's analysis population definition and group counts should be considered together, since the enrollment count alone does not describe how many participants contributed a particular outcome.

Over-dispersion is a general concern when data vary more than a chosen statistical model assumes. If a model underestimates variability, it may produce intervals that are too narrow and p-values that overstate evidence. The posted outcomes are continuous means with standard deviations, and the registry does not report a model-based analysis or a diagnostic assessment of dispersion. It is therefore not possible to say whether over-dispersion was assessed or whether it affected any sponsor analysis.

What do standardized effects and planning values mean?

A standardized effect expresses a difference relative to a measure of variability, allowing effects measured on different scales to be compared in broad terms. It does not replace the original logMAR difference, which remains more directly interpretable for this endpoint. The posted planning illustrations use fractions of the observed effect to show how estimated group size requirements change under stated assumptions. They are prospective illustrations based on the observed contrast, not a reconstruction of the trial's original design. The original sample-size justification is not reported in the registry record.

General explanation: power is the probability that a statistical test will detect an effect of a specified size if that effect is real, given a particular design and assumptions. Power calculations depend on the assumed effect, variability, allocation, significance level, and analysis method. The registry supplies assumptions for its planning illustrations but does not report the trial's own design assumptions, interim analyses, or full statistical plan. Those unknowns limit what can be inferred about the original design and conduct from the posted summary statistics alone.

11. Confidence Intervals and Precision

The primary mean difference is -0.04 logMAR, with an interval from -0.094 to 0.014. The interval crosses zero, so the data do not locate the primary difference precisely enough to rule out no difference under the posted interval calculation. Values on the negative side correspond to a lower mean in the Contralateral group; values on the positive side correspond to a higher mean in that group. Because lower logMAR denotes better visual acuity, those directions can be translated into the scale's stated meaning without implying that any particular difference is clinically important.

The span of the interval indicates uncertainty around the point estimate. A point estimate alone would give an incomplete account: it records the observed contrast but not how uncertain that estimate is. The interval makes clear that the primary result is compatible with a range of possible differences. The registry does not report a confidence level or interval construction method, so no additional precision claim should be attached to the limits.

For the secondary near outcome, the posted mean difference is -0.16, with an interval from -0.216 to -0.103. This interval lies below zero, unlike the primary interval. It represents greater separation from zero in the posted secondary comparison, but interval precision should be considered alongside the fact that this is a secondary result and that multiplicity handling is not reported. It does not settle whether the size of the difference is important to patients, since a threshold for clinical importance is not reported in the registry record.

Group standard deviations provide context for the spread of measurements, while the intervals describe uncertainty in the estimated contrast. Neither summary reveals every individual result. The primary group standard deviations are 0.148 and 0.133; the secondary group standard deviations are 0.158 and 0.134. The registry does not provide participant-level data or additional distributional summaries. Precision is also affected by the number contributing outcome measurements, which is smaller than the enrollment count. The record does not explain the difference or report how missing measurements were handled.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size illustrations translate the observed contrast into planning estimates under stated assumptions. The entries are participants per arm, not a total across both arms and not total events. The accompanying curve is a visual way to understand how the planning requirement changes as the effect used for planning changes; it should be read as an illustration rather than as a record of actual recruitment or an analysis result.

The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to a stated fraction of the observed effect. The listed rows use 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. The registry does not report the original design's sample-size assumptions or justification; these planning values do not establish what was used when the trial was planned.

The 80% power column gives the estimated participants per arm needed for an 80% chance of detecting the specified effect under those assumptions, if that effect is real. The 90% power column gives the corresponding planning estimate for a 90% chance. These are probabilities conditional on the assumptions, not guarantees for a particular study. A smaller target effect is harder to distinguish from random variation, so the planning illustration requires more participants per arm as the assumed fraction of the observed effect decreases.

This is not observed power. The figures are forward-looking planning illustrations based on the observed effect and stated assumptions, not a measure of how much power the completed trial had after its results were known. They should not be used to reinterpret the primary or secondary p-values as though the trial had been designed around these estimates.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.040; pooled standard deviation σ = 0.141.
2. n = 2 × (1.96 + 0.842)² × 0.141² / -0.040² = 194.8, rounded up to 195 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.04                      # observed difference in means
sigma <- 0.140922315514261                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1684007)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 195 (80% power), 261 (90% power)
 75% of observed effect: n per arm = 347 (80% power), 464 (90% power)
 50% of observed effect: n per arm = 780 (80% power), 1,044 (90% power)
power.t.test: 195.8 
Simulated power at n = 195 per arm: 0.796 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when more than one hypothesis test is considered. In general, repeated testing can increase the chance of obtaining a result that appears statistically notable even when there is no effect on the outcomes being tested. Common ways to address this issue include adjusting significance thresholds or specifying a hierarchy in which tests are interpreted in a defined order. The registry record does not report a multiplicity adjustment, a hierarchy for the primary and secondary endpoints, or a prespecified family of tests.

That absence matters most when interpreting the secondary result. It does not invalidate the posted numbers, but it means the unadjusted p-value should not be read as if it necessarily represented an error-controlled conclusion across all outcomes or analyses. The primary outcome is identified as primary in the record; however, details of the original analysis plan, including confirmation of prespecification and any planned secondary testing procedures, are not reported in the registry record.

The registry defines the primary analysis population as all subjects with both eyes implanted. The posted primary outcome includes 53 participants in the Bilateral group and 50 in the Contralateral group. Enrollment was 112. The record does not provide a participant flow diagram or explain why the group outcome counts differ from enrollment. It also does not describe the amount or pattern of missing endpoint data, reasons for missingness, or whether the posted analysis used any imputation or other missing-data procedure.

Missing data can affect interpretation if participants without measurements differ in relevant ways from those with measurements. General statistical explanation: complete-case summaries describe participants with observed measurements, while methods such as imputation rely on additional assumptions about missingness and outcomes. The record does not establish which missing-data assumptions, if any, were used. It is therefore not possible to assess from the registry alone how missing outcomes may have affected the estimates.

The record also does not report interim analyses, stopping rules, covariate adjustment, model diagnostics, or sensitivity analyses. These details should not be inferred from the randomized parallel design or from the posted summaries. The absence of such information is a reporting limitation; it is not evidence that a procedure was or was not used outside the registry record.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: vertigo (2.0%), dehydration (2.0%).

The adverse-event counts should be read as descriptive counts among participants at risk in each group. In the Bilateral group, 0 of 53 participants were recorded with a serious adverse event; in the Contralateral group, 2 of 50 were recorded with a serious adverse event. The registry also lists 3 participants with other adverse events in each group, with 53 and 50 participants at risk, respectively. These are counts, not estimates of comparative risk adjusted for other factors.

Vertigo and dehydration are listed among the top serious adverse-event terms, each with a registry percentage of 2.0%. The record does not give further detail about event timing, severity beyond the serious classification, relatedness to the intervention, or which group each term occurred in. Death counts are not reported in the registry record.

With these group sizes and event counts, the figures provide a limited description of events recorded during the study. A small count does not establish that an event cannot occur, and the absence of a recorded event in one group is not proof of no risk. The registry does not provide a formal comparative safety analysis or enough detail to make broader safety conclusions. The counts should be interpreted as the posted event record, not as evidence that either implantation strategy is safer.

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

The posted results describe average binocular visual acuity at two viewing distances at Day 90 from second-eye implantation. For the primary intermediate-distance endpoint, the Contralateral group had a lower mean logMAR value than the Bilateral group. The estimated mean difference was -0.04, but its interval includes zero and the unadjusted p-value was 0.149. The data therefore do not establish a clear difference in the primary outcome on the basis of this unadjusted comparison.

This is not the same as demonstrating that the two strategies are equivalent. A failure to establish a difference is not proof that the true difference is zero. Equivalence or non-inferiority requires a specific design, a prespecified margin, and an analysis suited to that question. Those elements are not reported in the registry record. Nor does the primary result establish that the strategies have identical effects for every participant; group means can conceal individual variation.

The secondary near-acuity result has a different inferential pattern, with an unadjusted difference and interval that do not include zero. It is evidence about the posted near-vision measure, not a replacement for the study's primary intermediate-vision question. Because the registry does not report multiplicity handling or the original analysis plan, the secondary finding should be interpreted cautiously and in context.

These findings do not, by themselves, establish whether an observed difference is meaningful to patients. A clinical-importance threshold, participant-reported outcomes, and broader measures of visual function are not reported in the registry record. LogMAR is a defined measure of acuity, but it is not a complete account of vision or quality of life.

The results also apply to the recorded population and follow-up: participants with both eyes implanted and measurement at the specified time point. The record does not give enough information to assess missing outcomes, participant flow, or longer-term results. The findings should not be generalized beyond the study conditions without additional evidence, and they do not constitute medical advice or a recommendation about lens choice.

17. Why This Trial Matters Statistically

This trial illustrates why the point estimate, interval, and p-value should be read together. The primary group means differ numerically, but the interval for the estimated contrast includes zero and the unadjusted p-value is 0.149. Focusing only on the direction of the means could make the evidence appear more conclusive than it is; focusing only on the p-value would omit the estimate's direction and range of uncertainty. Taken together, the summaries communicate both the observed contrast and the uncertainty around it.

The comparison is also a useful example of outcome-specific evidence. Intermediate and near acuity are related measures, yet their posted comparisons do not have the same degree of statistical evidence. Keeping the primary and secondary endpoints distinct helps avoid treating one result as if it answered every question about visual acuity. The lack of reported multiplicity procedures further underscores why secondary findings need careful qualification.

The study demonstrates the distinction between a completed trial's results and a planning illustration derived from an observed effect. The sample-size estimates answer a hypothetical design question under stated assumptions; they do not reveal the trial's original rationale and do not quantify observed power. The original design assumptions are not reported, so the planning values cannot be used to infer the sponsor's initial expectations.

Finally, the registry offers enough information to describe group averages, variability, and adverse-event counts, but not enough to reconstruct the full analysis or participant flow. That distinction is central to responsible biostatistical reading: a concise set of results can be informative while leaving important questions about methods and completeness unanswered.

18. 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 registry record leaves several trial-specific questions unresolved. Although it identifies the study as randomized and single-masked, it does not describe the randomization sequence, allocation concealment, or who was masked. The details of the original analysis plan, including the original sample-size justification and any prespecified model, are not reported. Interim analyses and stopping rules are also not reported in the registry record.

Enrollment was 112, while the posted primary outcome groups include 53 and 50 participants. The registry defines the analysis population as participants with both eyes implanted, but does not give a detailed flow of enrolled, treated, and analyzed participants or explain the difference in counts. Missing outcome data, reasons for missingness, and missing-data handling are not reported. These gaps limit assessment of how representative the posted summaries are of all enrolled participants.

The outcomes are measured at Day 90 from second-eye implantation. Longer-term visual acuity results are not reported in the registry record. The listed endpoints address binocular acuity at intermediate and near distances, but broader aspects of vision, patient experience, and function are not described. A threshold for clinical importance is also not reported, so statistical results cannot be translated into a judgment about meaningful benefit.

The primary and secondary comparisons are unadjusted recalculations from summary statistics, and the registry lists no reported analyses. Multiplicity procedures and the original sponsor analysis are not described. The adverse-event record gives counts and selected terms, but not detailed timing, relatedness, or a formal comparative safety analysis. These limitations do not erase the posted findings; they define the boundaries of what can be concluded from the registry record.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Clinical Outcome Study of Two Multifocal Intraocular Lenses (IOL) in Cataract Patients — NCT01684007.
• Registry record last updated 2015-06-22; status last verified 2015-05.
• Results first posted 2015-05-27.
• 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.

22. Record Summary

NCT01684007 was a completed randomized, single-masked, parallel-group study sponsored by Alcon Research, with enrollment of 112 and phase listed as NA. It compared bilateral implantation of the AcrySof® IQ ReSTOR® +2.5 D multifocal lens with +2.5 D implantation in the dominant eye and +3.0 D implantation in the fellow eye.

The primary outcome was binocular distance-corrected visual acuity at intermediate distance, measured at 60 cm on Day 90 from second-eye implantation. The unadjusted mean difference was -0.04 logMAR, with an interval from -0.094 to 0.014 and an unadjusted p-value of 0.149. The secondary near-acuity comparison favored a lower mean in the Contralateral group and had an unadjusted p-value of <0.001.

The record does not report the original sample-size assumptions, a detailed statistical plan, multiplicity procedures, participant flow, or missing-data handling. The posted results describe the recorded outcome summaries and should be interpreted within those reporting limits.