Quatera 700 vs. Centurion: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Quatera 700 vs. Centurion (NCT06225362), a randomized na study. The primary outcome is Central Corneal Thickness.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, double-masked, parallel-group study of two devices used in routine cataract surgery. The listed arms are Quatera 700 and Centurion Vision System. The posted arm results each report 40 participants. The overall enrollment is 80. The study concerns patients undergoing surgery in both eyes, but the record does not explain whether randomization, treatment assignment, and outcome analysis were organized by person, eye, or another unit.

The condition listed is cataract, and the devices are identified as phacoemulsification devices in the brief summary. The registry status is completed. The recorded study start is 2024-01-10, and the primary completion date is 2025-10-06. The phase field is listed as NA. The sponsor is Carolina Eyecare Physicians, LLC.

Double masking indicates that the record classifies the study as masked, but it does not specify which people were masked or how masking was maintained. The method used to generate the random allocation, concealment procedures, and any stratification are not reported in the registry record. Neither arm has a further description in the arm-description fields. The registry record does not state whether there were deviations from assigned devices or how these were handled.

The record lists 2 outcome measures and 0 analyses. It posts a primary outcome result for central corneal thickness but does not post secondary outcome results. Details of eligibility criteria, recruitment setting, surgeon experience, and follow-up beyond the primary measurement time are not reported in the registry record. These omissions limit how fully the design and conduct can be reconstructed from the registry information alone.

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: This was a split-eye study design. Each participant contributed two eyes, with one eye assigned to each intervention arm. Therefore, participants appear in both arms and may be counted more than once across arms in the Participant Flow table.

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 Central Corneal Thickness, measured over Postoperative day 1.

The primary endpoint is central corneal thickness, expressed in microns, measured by ultrasound pachymetry on postoperative day 1. The registry reports a mean and standard deviation for each device group. Thickness is a continuous measurement: each recorded value can take a range of numerical values rather than being classified only as an event or a category. Reporting group means therefore describes the average measured thickness in each arm, while standard deviations describe variation among the measurements.

In general, a continuous measurement can help characterize a postoperative physical finding and allow direct comparison of group averages. The registry record does not state why this endpoint was selected, what amount of difference would be clinically important, or whether a particular value represents a favorable or unfavorable result. It also does not provide a preoperative thickness result. Consequently, the posted endpoint describes thickness at the specified postoperative time; it does not, on its own, quantify change from before surgery.

The measurement method is ultrasound pachymetry. Details such as the number of readings, measurement protocol, assessor training, and handling of repeated measurements are not reported in the registry record. Since the summary describes surgery in both eyes, but does not state how measurements from the two eyes were incorporated into the analysis, the observational unit underlying the reported mean is not fully clear from the registry record.

7. Results Posted in the Registry

• Centurion Vision System: mean 565.60 versus 572.80 on control; difference -7.20 (95% CI -27.48 to 13.08), standardized effect d = -0.16; z-test p = 0.486.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous, so the registry reports a mean and standard deviation for each arm. The mean is the arithmetic average of the recorded thickness measurements. It gives a concise description of the center of a group’s measurements, but it does not show the full distribution or reveal whether values cluster closely around the average. The standard deviation describes the amount of spread around the mean. A larger standard deviation indicates more variability in the measurements, not necessarily greater uncertainty in the comparison by itself.

The arm summaries report a mean of 572.8 microns and a standard deviation of 49.4 for Quatera 700, and a mean of 565.6 microns and a standard deviation of 42.9 for Centurion Vision System. The registry also reports a pooled standard deviation of 46.26. Pooling combines information about variability across the groups under the assumptions used for that summary. The registry record does not state the full calculation method or whether equal variances were assumed in the trial's own analysis.

The reported mean difference is -7.2 microns, with Centurion Vision System compared against Quatera 700. A difference between means retains the outcome’s original unit, making the estimate interpretable in microns. The sign depends on the order of comparison: in the posted contrast, negative values correspond to a lower Centurion mean. The estimate is a summary of the observed group averages, not an individual-level treatment effect and not a measure of how many measurements favored either device.

A confidence interval describes a range of values for the contrast that are reasonably compatible with the data and the calculation method. The interval reported for this difference is -27.48 to 13.08 microns. Its span includes zero and values in both directions. That makes the point estimate less conclusive about the direction of a difference. A confidence interval is not a range containing a fixed proportion of individual measurements; individual measurements have their own variability, described in part by the standard deviations.

The posted unadjusted p value is 0.486. In general, a p value assesses how unusual the data, or results more extreme, would be under a specified null hypothesis and statistical model. It does not measure the size or clinical importance of an effect. It also does not give the probability that the null hypothesis is true. The registry record does not report the trial's own significance threshold, detailed statistical test, covariate adjustment, or analysis plan. Therefore, the posted p value can be described, but the full inferential procedure cannot be verified from the registry record.

The standardized effect estimate is -0.156. In general, standardizing a mean difference expresses it relative to variability, which can support comparisons across outcomes measured on different scales. Such a value is less directly interpretable clinically than the original difference in microns. The standardization method and its role in the sponsor's analysis are not reported in the registry record. The negative sign follows the same comparison order as the raw mean difference.

The record describes random allocation and double masking. Random allocation is intended to make assigned groups comparable on average, including on factors not measured, but the registry record does not describe how the sequence was generated or concealed. Masking can reduce some forms of bias when participants or study personnel do not know the assigned group, but the people masked and procedures used are not reported. These design labels do not resolve uncertainties about outcome measurement or analysis.

The brief summary specifies surgery in both eyes, but the reported arm sample sizes and summaries do not explain whether both eyes contributed to the endpoint or how correlation between eyes was handled. Measurements from two eyes of one person may be related; in general, treating correlated observations as independent can make standard errors too small. Whether that issue applies to the posted analysis, and what method was used if both eyes were included, are not reported in the registry record. The record also does not describe missing-data handling, analysis populations, baseline adjustment, or whether the posted comparison follows the randomized assignment.

These distinctions matter because descriptive summaries, a treatment contrast, and inferential calculations answer related but different questions. The means describe the observed groups; the difference estimates their average contrast; the interval describes uncertainty in that contrast under a statistical method; and the p value summarizes evidence relative to a null model. None of these alone establishes clinical importance, equivalence, or the result for outcomes that were not posted.

10. Confidence Intervals and Precision

The reported mean difference is -7.2 microns, and its confidence interval extends from -27.48 to 13.08 microns. This interval communicates uncertainty around the estimated average contrast. It is not a confidence interval for individual measurements, and it does not imply that every plausible value is equally likely. Under the method used to construct it, the interval provides a set of values compatible with the observed data at the interval’s confidence level; the confidence level itself is not reported in the registry record.

Zero lies within the interval. Thus the posted result does not pin down whether the Centurion mean is lower or higher than the Quatera mean in the broader population represented by the statistical model. The interval includes both negative and positive differences, so the point estimate’s negative direction should not be read as a definitive direction of effect. The posted p value of 0.486 is consistent with the interval not excluding a zero difference, although the record does not give enough detail to verify the inferential methods or their assumptions.

Precision is distinct from the numerical size of the estimate. An estimate can be near zero while remaining uncertain, and a confidence interval can include a wide range of effects. Whether the interval rules out differences that matter clinically depends on a clinical importance threshold. No such threshold is reported in the registry record, so the interval cannot be used to establish equivalence or to determine that all clinically meaningful differences have been excluded.

The standard deviations, 49.4 microns and 42.9 microns, describe observed spread within the arms, whereas the confidence interval describes uncertainty in the mean difference. The registry record does not report an interval for each arm mean or provide further distributional summaries. Interpretation is also constrained by unreported details about the use of measurements from both eyes, missing observations, and the exact analysis method.

11. 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 expressed as participants per arm, not as total events. The scenario uses the observed effect as its reference and gives illustrations for detecting 100% of that effect, 75% of that effect, and 50% of that effect. At each effect assumption, the display gives the number of participants per arm for 80% power and for 90% power. These are planning illustrations computed from the observed effect, not the trial's original design assumptions; the original design assumptions are not reported in the registry record.

The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The calculation uses an effect to detect equal to the stated fraction of the observed effect. For the scenario based on 100% of the observed effect, the figures are 649 participants per arm for 80% power and 868 participants per arm for 90% power. For 75% of the observed effect, the figures are 1,153 and 1,543 participants per arm, respectively. For 50% of the observed effect, the figures are 2,593 and 3,471 participants per arm, respectively.

In plain terms, 80% power describes a design that would detect the assumed effect in 80% of repeated studies under the planning model, if that effect and the assumptions were correct. The 90% column uses the same idea with a higher probability of detection, which requires more participants for the stated scenarios. Smaller effects are harder to distinguish from random variation, so detecting a smaller fraction of the observed effect requires more participants per arm. These planning figures are not observed power.

12. 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 = -7.200; pooled standard deviation σ = 46.264.
2. n = 2 × (1.96 + 0.842)² × 46.264² / -7.200² = 648.1, rounded up to 649 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 <- -7.19999999999993                      # observed difference in means
sigma <- 46.264295088113                     # 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(6225362)
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 = 649 (80% power), 868 (90% power)
 75% of observed effect: n per arm = 1,153 (80% power), 1,543 (90% power)
 50% of observed effect: n per arm = 2,593 (80% power), 3,471 (90% power)
power.t.test: 649.1 
Simulated power at n = 649 per arm: 0.800 (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.

13. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures but reports no secondary outcome results. It lists 0 analyses. The primary result discussed in the registry is central corneal thickness on postoperative day 1. The full list of outcome measures, any prespecified hierarchy among them, and the intended relationship between primary and secondary analyses are not available in the posted record.

Multiplicity arises when several outcomes, time points, subgroups, or statistical comparisons are tested. In general, testing more hypotheses can increase the chance of at least one apparently notable result by chance. A trial may address this through a prespecified hierarchy or adjustment, but whether either approach was used in this study is not reported in the registry record. The posted unadjusted p value should therefore not be interpreted as evidence that multiplicity was or was not handled.

The registry record does not report missing-data counts for the primary outcome, reasons for missing measurements, or an imputation or other missing-data method. It also does not identify the analysis population, such as whether the primary comparison included all randomized participants, only participants with measurements, or another defined group. The posted arm summaries do not clarify how any unavailable measurements were treated.

The brief summary describes surgery in both eyes, but the record does not state whether the outcome was analyzed at the participant or eye level, how measurements from paired eyes were combined, or how any within-person correlation was accounted for. These are material details for interpreting uncertainty in an eye-related endpoint. The record also does not state whether the comparison was adjusted for baseline measurements or other covariates. These absences do not establish that a method was not used; they mean that the method is not reported in the registry record.

14. 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 non-serious adverse event terms

The adverse-event record reports 0 participants affected by serious adverse events in the Quatera 700 arm and 0 in the Centurion arm. It reports 3 participants affected by other adverse events in the Quatera 700 arm and 4 in the Centurion arm. Deaths are reported as 0 in each arm. These are the posted counts; they do not by themselves establish that the devices caused or did not cause an event.

The record does not provide serious-event terms, and it does not describe the types, timing, severity, or duration of the other adverse events. It also does not report how events were collected, how long safety follow-up lasted, or how the relationship to the device or procedure was assessed. The counts therefore offer limited information about the safety experience recorded in the registry, rather than a complete safety profile.

These figures should be read as group-specific reported counts, not as a comparison adjusted for differences or as proof of equal risk. The registry record does not state whether all participants completed the same safety follow-up or whether any events were missing from the record. No conclusions about safety beyond the posted counts are warranted from these data alone.

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

The result describes a comparison of average central corneal thickness measured by ultrasound pachymetry on postoperative day 1. The Quatera 700 arm mean is 572.8 microns, and the Centurion Vision System arm mean is 565.6 microns. The estimated mean difference for Centurion relative to Quatera is -7.2 microns. The confidence interval, from -27.48 to 13.08 microns, includes zero and values on either side of zero. The posted result therefore leaves uncertainty about the direction and size of the average difference.

This is not evidence that the devices are equivalent. Equivalence requires a prespecified margin defining differences small enough to be considered unimportant, together with an analysis designed to assess that question. No equivalence margin or such analysis is reported in the registry record. Nor does the result prove that a difference exists: the interval and p value do not establish a clear separation in average thickness.

The result does not describe each participant's or eye's measurement, and it does not reveal whether the devices differ on outcomes that were not posted. It concerns a measurement at one postoperative time point. Without a posted baseline thickness result, it cannot quantify change from before surgery. The registry record does not give a clinical importance threshold, so the numerical estimate cannot be translated into a claim about clinical relevance.

The finding should also be interpreted in light of missing design and analysis details. The record does not explain how both eyes were handled, what analysis population was used, how missing measurements were treated, or what statistical plan was specified. It does not provide secondary outcome results. Those limits leave unanswered questions about the scope and robustness of the comparison. The appropriate reading is a reported group-average result with uncertainty, not a comprehensive judgment about the devices or the full course of cataract surgery.

16. Why This Trial Matters Statistically

This trial illustrates why an estimate should be read together with its uncertainty. The reported mean difference is -7.2 microns, but the confidence interval extends from -27.48 to 13.08 microns. Looking only at the point estimate would obscure that the data are compatible with differences in either direction. Looking only at the p value would also leave out the scale and range of the estimated contrast. For statistical interpretation, the mean difference, interval, and measurement unit answer complementary questions.

The endpoint is continuous and measured in microns, allowing a group-average comparison on the original scale. At the same time, the registry record does not report a threshold for clinical importance. Statistical uncertainty and clinical importance are separate: a numerical difference may be estimated with varying precision, while its practical meaning depends on context and a meaningful threshold. The record does not supply the basis for that clinical judgment.

The study's description of surgery in both eyes raises an important analysis question. In general, measurements from a person's two eyes may be correlated, and the handling of such correlation can affect uncertainty estimates. The registry record does not state whether both eyes were included in the outcome analysis or how they were handled. This is a useful reminder that the unit of randomization, unit of measurement, and unit of analysis need to be clear when interpreting clinical results.

Finally, a completed registry record can provide useful design, outcome, and safety information while still leaving important methodological details unreported. Here, the trial is labeled randomized and double-masked, but the procedures behind those labels and the full statistical plan are not given. Distinguishing what the result directly reports from what remains undocumented is essential to keeping conclusions proportionate to the evidence.

17. 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 offers limited detail for evaluating the conduct and analysis of this trial. It identifies randomization, double masking, and a parallel design, but does not describe the allocation sequence, allocation concealment, or which people were masked. The arm descriptions are blank, so details of how each device was used and whether the surgical procedures differed are not reported in the registry record.

The study summary specifies surgery in both eyes, while the record does not explain whether the primary outcome was assessed for one eye or both, how measurements were selected or combined, or whether the analysis accounted for paired eyes. The number of participants reported in each arm does not resolve those questions about the measurement and analysis units. The registry record also does not report baseline thickness, so the posted postoperative values cannot be interpreted as changes from baseline.

Further limitations include the absence of a stated clinical importance threshold, detailed eligibility criteria, missing-data methods, analysis populations, and the trial's own statistical plan. The record lists 0 analyses and has no posted secondary outcome results. It does not describe the measurement protocol beyond ultrasound pachymetry or provide information about later follow-up. These gaps restrict assessment of precision, generalizability, and whether the posted result reflects the intended analysis.

The record identifies a completed study but does not give details about recruitment setting or participant characteristics beyond the condition and surgery context. The available information therefore cannot establish how closely the enrolled population reflects other cataract-surgery populations. These limitations concern what is reported in the registry record; they do not show that a procedure or analysis was absent from the trial itself.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Quatera 700 vs. Centurion — NCT06225362.
• Registry record last updated 2026-04-01; status last verified 2026-03.
• Results first posted 2026-04-01.
• 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.

21. Record Summary

The registry record describes a completed, randomized, double-masked, parallel-group comparison of Quatera 700 and Centurion Vision System for routine cataract surgery in both eyes. Enrollment is listed as 80, with 40 participants reported in each device arm. The listed condition is cataract, and the sponsor is Carolina Eyecare Physicians, LLC.

The primary outcome is mean central corneal thickness in microns, measured by ultrasound pachymetry on postoperative day 1. The reported means are 572.8 for Quatera 700 and 565.6 for Centurion Vision System. The mean difference for Centurion relative to Quatera is -7.2 microns, with a confidence interval from -27.48 to 13.08 and an unadjusted p value of 0.486. The interval includes zero, leaving uncertainty about the direction and size of the average difference.

The record reports 0 serious adverse events in each arm and deaths of 0 in each arm. It reports 3 participants affected by other adverse events in the Quatera 700 arm and 4 in the Centurion arm. Details on the event types and statistical plan are not reported in the registry record.