Comparison of Centurion® Vision System With Balanced Tip and the Infiniti® Vision System With the Mini Flared Kelman (MFK) Tip During Cataract Extraction Surgery of Hard Lenses: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparison of Centurion® Vision System With Balanced Tip and the Infiniti® Vision System With the Mini Flared Kelman (MFK) Tip During Cataract Extraction Surgery of Hard Lenses (NCT02502526), a randomized na study. The primary outcome is Cumulative Dissipated Energy (CDE).

2. Clinical Question

The central question is whether cumulative dissipated energy during cataract extraction differed between the Centurion® Vision System used with the 45° Balanced Tip and the Infiniti® Vision System used with the 45° MFK Tip. The registry describes the study as focused on hard lenses and identifies cataracts as the condition. CDE is an operative measure expressed in percent-seconds; the registry says lower CDE indicates less energy at the incision site.

3. Trial Design

The registry describes NCT02502526 as a randomized, single-masked, parallel-group device study with enrollment of 231. Its status is completed. The listed phase is NA. The sponsor is Alcon Research. The study started on 2015-07-27, and primary completion was 2017-03-23. The record describes one routine surgical procedure followed by 3 months (+/- 14 days) of postoperative follow-up for each arm.

Three device configurations were studied: Centurion with the 45° Balanced Tip, Centurion with the 45° MFK Tip, and Infiniti with the 45° MFK Tip. The descriptions pair the Centurion arms with the INTREPID® Ultra Infusion Sleeve and the Infiniti arm with the Ultra Infusion Sleeve. For the primary outcome, the posted arm summaries include 57.0 participants for CVS Bal and 58.0 for IVS MFK; the stated population is ITT with non-missing data. The additional CDE summaries include CVS MFK as well.

Randomized allocation is recorded, but the sequence-generation method, allocation concealment, and the identity of those masked are not reported in the registry record. The original design’s target group sizes and sample-size justification are not reported in the registry record. The record gives the trial’s overall enrollment, but the outcome-specific analysis populations are identified through the posted endpoint summaries and analysis descriptions.

The primary endpoint was CDE on Day 0 (operative day). BSS fluid used, measured in milliliters, was a secondary outcome on the same timeframe. The registry lists a total of 3 outcome measures and 5 analyses. The clinical question is therefore narrow and intraoperative: how the named system-and-tip configurations compare on energy use, with fluid use also assessed.

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 231 subjects enrolled, 49 were exited prior to randomization (34 due to randomization suspension, 14 due to screen failure, and 1 due to subject death). This reporting group includes all randomized subjects (182).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: ITT with non-missing data

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: ITT

6. Primary Endpoint

The registry lists the primary outcome as Cumulative Dissipated Energy (CDE), measured over Day 0 (operative day).

The primary endpoint is Cumulative Dissipated Energy (CDE), measured in percent-seconds on Day 0 (operative day). The registry defines CDE as energy dissipated by the ultrasound tip and infusion sleeve at the incision point, described as 5.6mm back from the cutting edge of the tip, during removal of the cataractous lens. CDE was reported on the Vision System interface. The registry states that a lower value indicates that less energy was present at the incision site.

This endpoint is useful for comparing the device configurations on a directly measured operative quantity connected to their use during phacoemulsification. It does not directly measure a later health outcome, nor does the record establish that a particular CDE value necessarily corresponds to a particular postoperative benefit or harm. The measure is expressed as a mean and standard deviation, so the posted arm summaries describe both the average and the spread of observed CDE values.

Only one eye, designated the study eye, contributed to the analysis. The primary outcome was prespecified for CVS Bal and IVS MFK, and the stated population was ITT with non-missing data. How missing endpoint observations were handled beyond that population description is not reported in the registry record.

7. Results Posted in the Registry

• IVS MFK: mean 11.40 versus 6.20 on control; difference 5.20 (95% CI 2.91 to 7.49), standardized effect d = 0.82; z-test p = <0.001.

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.

Cumulative Dissipated Energy (CDE)

• 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:
  • CVS MFK: mean 11.60 versus 6.20 on control; difference 5.40 (95% CI 3.36 to 7.44), standardized effect d = 0.97; z-test p = <0.001.
  • IVS MFK: mean 11.40 versus 6.20 on control; difference 5.20 (95% CI 2.91 to 7.49), standardized effect d = 0.82; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for CVS MFK than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for IVS MFK than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Balanced Salt Solution (BSS) Fluid Used

• 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:
  • CVS MFK: mean 101.70 versus 95.80 on control; difference 5.90 (95% CI -6.47 to 18.27), standardized effect d = 0.18; z-test p = 0.350.
  • IVS MFK: mean 94.10 versus 95.80 on control; difference -1.70 (95% CI -14.13 to 10.73), standardized effect d = -0.05; z-test p = 0.789.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between CVS MFK and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between IVS MFK and the control. The interval gives the range of effects that remain compatible with the data.

Across the secondary outcomes, the pattern is not uniform. CDE comparisons involving the Centurion MFK arm extend the primary energy outcome to another device configuration, while BSS fluid use provides a separate measure of operative resource use. The posted means and sponsor analyses indicate that the CDE contrasts and the BSS contrasts do not all present the same degree of separation. This means the primary CDE finding should not be generalized automatically to every secondary outcome or every device comparison.

The secondary CDE results provide context for whether the observed primary pattern is confined to the balanced-tip comparison or also appears when configurations share the MFK tip. BSS fluid use is conceptually distinct from energy dissipation, so a lack of a clear contrast in fluid use would not contradict a CDE difference. These outcomes measure different aspects of surgery and need not move together.

The registry reports ANCOVA tests for secondary comparisons, but the record does not report adjusted estimates or confidence intervals for those analyses. The available unadjusted recalculations are useful descriptive contrasts, but they should not be treated as substitutes for the sponsor’s adjusted tests. Secondary results also carry less weight for confirmatory claims when multiple outcomes and comparisons are examined. Without a reported multiplicity strategy, an isolated secondary p-value is harder to interpret as definitive evidence.

The overall takeaway is that the primary outcome has the clearest reported statistical evidence, whereas the secondary outcomes add descriptive and exploratory context. The record does not report a hierarchy or multiplicity adjustment establishing how secondary tests should affect the primary conclusion. Accordingly, secondary findings are best read as supporting context for distinct measures, not as a single composite verdict on the devices.

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

• Cumulative Dissipated Energy (CDE)
• Balanced Salt Solution (BSS) Fluid Used

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous: it records CDE as a numeric quantity in percent-seconds. A group mean describes the average observed value, while the standard deviation describes how spread out observations are around that group mean. These summaries answer different questions. A lower average indicates a lower group-level mean, while a smaller standard deviation indicates less observed variability; neither tells the full story of the individual values.

What does a mean difference express?

A mean difference compares the two group averages in the same measurement units. The recalculated primary contrast is expressed as IVS MFK minus CVS Bal, so a positive difference corresponds to a higher mean in IVS MFK and, equivalently, a lower mean in CVS Bal. The estimate of 5.2 percent-seconds is an unadjusted comparison derived from posted group summaries. It is not the sponsor’s adjusted ANCOVA estimate.

Unadjusted recalculations are useful as a transparent check on the direction and approximate scale of a difference using arm means and measures of spread. They do not account for covariates or other adjustments that may be part of a model-based analysis. The registry identifies ANCOVA as the sponsor’s method, but the covariates, model specification, and handling of assumptions are not reported in the registry record. The sponsor’s test result should therefore be distinguished from the simple recalculation.

How should a confidence interval be read?

A confidence interval describes uncertainty around an estimated effect under the assumptions of the method used. For a mean difference, the interval gives a range of values compatible with the observed data and calculation procedure. If the interval includes zero, the data are compatible with no mean difference under that procedure; if it excludes zero, they are less compatible with that null value. This is a general statistical explanation, not a statement that the interval guarantees where the true effect lies.

The recalculated interval is based on the unadjusted summary comparison. It should not be treated as the interval for the ANCOVA result, because the registry does not report an ANCOVA interval. Differences in adjustment and model assumptions can affect an estimate, its uncertainty, or both.

What does the p-value contribute?

A p-value measures how unusual data at least as incompatible with a specified null hypothesis would be under the statistical model, if that null hypothesis and model assumptions held. 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 unadjusted recalculation reports p <0.001, while the registry’s ANCOVA result for the primary comparison is p <.001. Both report strong statistical evidence against the no-difference null under their respective analyses, but they are not the same analysis.

The word “superiority” appears as the registry’s analysis type. It describes the stated hypothesis-testing framework, not proof that one configuration is preferable in every clinical respect. The record’s primary question concerns CDE, and other outcomes may have different patterns.

Why might variability matter?

Variation affects how precisely group means and their difference can be estimated. A relatively wide spread means that individual observations vary considerably around the average. When variability is large relative to a mean difference, estimates tend to be less precise for a given amount of data. This general principle helps explain why both the means and their standard deviations matter when interpreting a continuous outcome. It does not imply a new calculation or an estimate of individual-level effects.

The posted recalculation also reports a pooled standard deviation and a standardized effect measure. Such standardized summaries express a mean difference relative to the observed spread, which can help compare effects measured on different scales. They do not replace the original-unit difference, which is easier to connect to the endpoint’s percent-seconds scale. No clinical threshold for interpreting either measure is reported in the registry record.

Finally, the analysis population is described as ITT with non-missing data. This wording indicates the named analysis population but does not explain how missing values were addressed, whether any imputation was used, or how departures from assigned treatment were treated. Those details are not reported in the registry record, so conclusions about the precise analysis implementation should remain limited.

11. Confidence Intervals and Precision

The recalculated primary mean difference is 5.2 percent-seconds, with a 95% confidence interval from 2.911 to 7.489. In plain terms, the interval describes uncertainty around the unadjusted group-average contrast, with positive values corresponding to higher mean CDE in IVS MFK than in CVS Bal under the subtraction order used. The interval does not describe the range of individual measurements, nor does it quantify the probability that a treatment configuration is better.

The interval excludes zero, consistent with the recalculated p-value of p <0.001. This agreement is expected because both summaries reflect evidence concerning the same unadjusted mean contrast. The lower and upper limits still allow a range of effect sizes, so statistical evidence of a nonzero contrast is not the same as exact knowledge of its magnitude.

The confidence interval is calculated from posted summary statistics, not from the sponsor’s ANCOVA model. The registry reports the ANCOVA p-value for the primary comparison but does not report its estimate or confidence interval. Consequently, the recalculated interval should not be presented as the adjusted interval or as a complete description of the sponsor’s model result.

Precision also depends on the observed variability and the analysis population. The standard deviations differ across the primary arms, and the endpoint population is ITT with non-missing data. The registry does not report details of missing-data handling or the covariates used in ANCOVA. Those omissions limit how fully the adjusted estimate and its precision can be assessed from the record.

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 planning figures are participants per arm, not total events. They are illustrations based on the observed effect, rather than the trial’s original design calculations. The stated 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 trial’s own original sample-size assumptions and justification are not reported in the registry record.

The 80% power column gives the number of participants per arm in a hypothetical design that would have an 80% chance of detecting the selected effect under those assumptions, if the effect and model assumptions used for planning were correct. The 90% power column expresses the corresponding planning target with a higher chance of detecting that effect. These are design calculations, not guarantees that a future study will obtain a statistically significant result.

For the primary comparison, planning for 100% of the observed effect gives 24 participants per arm for 80% power and 31 participants per arm for 90% power. Planning for 75% of the observed effect gives 42 participants per arm for 80% power and 55 participants per arm for 90% power. Planning for 50% of the observed effect gives 93 participants per arm for 80% power and 124 participants per arm for 90% power. The pattern illustrates the general principle that smaller effects are harder to detect and require more participants for the same power target.

These figures are not observed power. They are prospective planning illustrations that reuse an effect estimated from the trial, and that estimate itself is uncertain. They should not be interpreted as proving that the study was adequately designed for other outcomes, analyses, or effect sizes.

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 = 5.200; pooled standard deviation σ = 6.306.
2. n = 2 × (1.96 + 0.842)² × 6.306² / 5.200² = 23.1, rounded up to 24 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 <- 5.2                      # observed difference in means
sigma <- 6.30555310817378                     # 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(2502526)
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 = 24 (80% power), 31 (90% power)
 75% of observed effect: n per arm = 42 (80% power), 55 (90% power)
 50% of observed effect: n per arm = 93 (80% power), 124 (90% power)
power.t.test: 24.1 
Simulated power at n = 24 per arm: 0.802 (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. Analyses Reported by the Sponsor

The registry reports the sponsor’s primary analysis as ANCOVA for CVS Bal versus IVS MFK, with a superiority designation and p <.001. The record does not include the adjusted effect estimate, its confidence interval, or the ANCOVA covariates. The sponsor’s result therefore establishes the reported test outcome, but the record does not permit a full assessment of the adjusted effect’s size or precision.

The recalculated result uses the posted group means, standard deviations, and analysis counts to form a simple unadjusted comparison. It gives a mean difference of 5.2 percent-seconds, with a 95% confidence interval from 2.911 to 7.489 and p <0.001. Its direction agrees with the arm means and with the sponsor’s reported significance result. It is not an independent trial dataset or a reconstruction of the ANCOVA.

Because the record reports the sponsor’s ANCOVA p-value but not its estimate, the recalculation adds a descriptive estimate in the original units without replacing the sponsor’s analysis. The distinction matters: adjusted and unadjusted analyses can answer closely related but not identical questions. Covariate adjustment may alter the estimated contrast and its uncertainty. The necessary model details are not reported in the registry record.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple outcome measures and analyses, including the primary CDE comparison, further CDE comparisons, and BSS fluid comparisons. Testing several hypotheses creates a multiplicity issue: even when each individual test uses a conventional significance threshold, the chance of at least one false-positive result across a collection of tests can increase. This is a general statistical concern and does not establish that any particular reported result is false.

A prespecified hierarchy, family-wise error procedure, false-discovery approach, or other multiplicity plan can clarify which results are confirmatory and how uncertainty should be interpreted across tests. Such a strategy is not reported in the registry record. It is therefore not possible to determine from the record whether the secondary comparisons were adjusted for multiple testing, whether one comparison had priority over another, or how the primary analysis was protected against multiplicity.

The record labels the primary outcome as prespecified for CVS Bal and IVS MFK and identifies the sponsor analysis as superiority testing. Those details help define the primary question, but they do not supply the full statistical analysis plan. The protocol’s planned covariates, model diagnostics, handling of missing data, and rules for analysis populations are not reported in the registry record.

The primary analysis population is described as ITT with non-missing data. The phrase does not state how many otherwise eligible observations lacked the endpoint, why any values were missing, whether missingness was assessed by treatment group, or whether imputation or sensitivity analyses were performed. These details matter because estimates based only on observed values can be affected if missingness is related to outcome or treatment. The registry record does not allow that possibility to be evaluated.

Likewise, the record does not report a detailed account of deviations from assigned treatment or whether all randomized participants were included in each endpoint analysis. The listed endpoint group counts are analysis counts, and the overall enrollment should not be assumed to equal the analysis population for a particular comparison. These limits counsel a focused reading of the posted results rather than claims about unreported analyses.

16. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: posterior capsule rupture (1.8%), vitreous loss (1.8%), vitrectomy (1.8%), subdural haematoma (1.7%), colon cancer metastatic (1.7%).

The registry’s serious adverse event figures list 1 affected participant among 57 at risk for CVS Bal, 0 among 57 for CVS MFK, and 3 among 59 for IVS MFK. Deaths are listed as 0 in each of the three groups. These counts describe the registry’s recorded serious adverse event summaries; they do not establish that an event was caused by a device or that groups differ in safety.

The record also lists other adverse events as affecting 14 among 57 at risk in CVS Bal, 17 among 57 in CVS MFK, and 11 among 59 in IVS MFK. The listed serious-event terms include Posterior capsule rupture, Vitreous loss, Vitrectomy, Subdural haematoma, Colon cancer metastatic, and Hypertensive crisis, each with the percentages shown in the registry record. The record does not provide enough context in these summaries to infer causality or compare event types reliably.

These are descriptive counts from a trial focused on operative outcomes. The registry record does not report a detailed safety analysis plan, event adjudication process, or exposure-adjusted comparisons. Small event counts should be interpreted cautiously and do not settle relative safety.

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

The posted results support a specific statistical statement: the registry reports a significant ANCOVA comparison for mean CDE between CVS Bal and IVS MFK, and the unadjusted recalculation also estimates a difference in the same direction. In the observed data, mean CDE was lower in the balanced-tip Centurion group than in the Infiniti MFK group. The estimated unadjusted contrast is expressed in percent-seconds, with a confidence interval that excludes zero.

That finding does not establish that one configuration is better on every aspect of cataract surgery. CDE is an intraoperative energy measure, not a direct measure of visual function, long-term outcomes, or overall patient benefit. The record identifies BSS use as a secondary outcome, but separate measures should not be collapsed into a general claim about clinical performance.

Statistical significance also does not determine clinical importance. The registry does not report a threshold defining a clinically meaningful CDE difference, nor does it connect the observed difference to postoperative consequences. The estimate should therefore be interpreted as a difference in the measured endpoint, not as proof of a particular patient-level effect.

The findings apply to the device configurations, hard-lens study setting, and endpoint population described in the registry. They do not automatically generalize to other systems, tips, lens grades, surgical settings, or populations. Details about masking, covariate adjustment, missing-data handling, and multiplicity are incomplete in the record. Those limitations do not erase the reported result, but they bound what can be concluded from it.

Finally, group means summarize distributions rather than individual outcomes. A lower group mean does not imply that every participant in that group had lower CDE than every participant in the comparator group. The appropriate conclusion remains group-level and endpoint-specific.

18. Why This Trial Matters Statistically

This trial illustrates why statistical interpretation should separate the estimated effect, uncertainty, and clinical meaning. CDE is a continuous operative measure, and the primary result is expressed as a difference in its original units. That makes the contrast more interpretable than a significance label alone, while the confidence interval shows that the estimate is not exact.

The registry also makes visible a distinction between sponsor analysis and summary-based recalculation. The sponsor reports ANCOVA, while the posted recalculation is unadjusted. Agreement in direction and significance is reassuring as a consistency check, but the analyses are not interchangeable, particularly because the adjusted estimate and model details are absent from the record.

Multiple device configurations allow related but distinct questions about the system and tip choices. At the same time, multiple outcomes and comparisons require care in deciding how much weight to give each result. Without a reported multiplicity strategy, the primary outcome is the clearest anchor, and secondary outcomes are better considered contextual rather than definitive.

The planning illustrations further show how sample-size requirements depend on the effect a future study aims to detect. Planning on a smaller fraction of an observed effect calls for more participants per arm. That is a general design lesson, not evidence about the original study’s planning or achieved power.

Together, these points make the trial useful for understanding how a strong statistical signal on a prespecified technical endpoint can coexist with uncertainty about adjustment, multiplicity, clinical importance, and broader outcomes.

19. 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 does not report the detailed randomization procedure, allocation concealment, or who was masked. It also does not identify the ANCOVA covariates or provide adjusted effect estimates and confidence intervals. This restricts assessment of how the sponsor’s model was specified and how much the adjusted result differs from the simple group summaries.

The primary outcome population is described as ITT with non-missing data, but missing-data counts, reasons, methods of handling missing values, and sensitivity analyses are not reported in the registry record. The relationship between the endpoint analysis counts and all randomized participants therefore cannot be fully evaluated from the record alone.

The registry does not report the original sample-size justification or the assumptions used to plan the study. The planning illustrations based on observed effects cannot substitute for those design assumptions. Nor does the record report a multiplicity strategy for the several outcomes and comparisons, which limits interpretation of secondary testing.

CDE is a technical operative outcome measured on the procedure day. The registry does not report a clinically meaningful threshold for the measure or establish how a CDE difference relates to later patient outcomes. Follow-up is described as 3 months (+/- 14 days), but the posted primary endpoint is intraoperative, and the record’s primary result does not resolve longer-term questions.

Safety summaries are descriptive and provide limited detail about event context, adjudication, or causal assessment. Generalization is also limited to the named devices and tips in the hard-lens cataract surgery setting; the record does not establish results for other configurations or clinical contexts.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Comparison of Centurion® Vision System With Balanced Tip and the Infiniti® Vision System With the Mini Flared Kelman (MFK) Tip During Cataract Extraction Surgery of Hard Lenses — NCT02502526.
• Registry record last updated 2018-07-02; status last verified 2018-04.
• Results first posted 2018-04-18.
• 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.

23. Record Summary

NCT02502526 is a completed randomized, single-masked, parallel-group device study sponsored by Alcon Research, with enrollment of 231. It compared three cataract surgery device configurations. The primary question concerned Day 0 CDE for Centurion with the 45° Balanced Tip versus Infiniti with the 45° MFK Tip.

The posted means were 6.2 percent-seconds for CVS Bal and 11.4 percent-seconds for IVS MFK. The sponsor reports ANCOVA p <.001. An unadjusted recalculation estimates a mean difference of 5.2 percent-seconds, with a 95% confidence interval from 2.911 to 7.489 and p <0.001. BSS fluid use was also assessed as a secondary endpoint.

The record supports an endpoint-specific statistical interpretation, not a broad claim about clinical benefit or overall device performance. Adjusted estimates, detailed missing-data procedures, and multiplicity methods are not reported in the registry record.