This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Pharmacokinetic Evaluation of Moxifloxacin in Vigadexa® in Aqueous Humor Samples Following Preoperative Antibiotic/Steroid Dosing in Cataract Surgery Patients (NCT01859702), a na phase 4 study. The primary outcome is Mean Aqueous Humor Concentration of Moxifloxacin.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01859702 |
| Phase | Phase 4 |
| Condition | Cataract |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 36 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Alcon Research |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned cataract surgery patients. The primary measure was defined for a per-protocol population: subjects who met the inclusion and exclusion criteria, received all doses of the test product, and underwent cataract surgery with aqueous-humor sampling. The registry record does not report how many subjects met that definition or contributed to the endpoint.
Intervention
The intervention was Vigadexa®, an ophthalmic solution containing moxifloxacin 0.5% and dexamethasone 0.1%. The study-eye schedule specified 1 drop 2 days before surgery, 1 drop 4 times a day the day before surgery, and 1 drop 60 minutes before the procedure on the day of surgery.
Comparator
No comparator group is described. The design is listed as single group, allocation is listed as not applicable, and masking is listed as none. Consequently, the registry record does not support a between-group treatment comparison.
Primary question
The primary question was what mean moxifloxacin concentration would be measured in aqueous humor on the operative day after the specified preoperative combination-drug dosing. This is a pharmacokinetic question about drug concentration in a sampled eye fluid, not a question about a clinical outcome such as cataract-surgery success.
3. Trial Design
The registry describes a completed Phase 4, single-group study sponsored by Alcon Research. It lists cataract as the condition and an enrollment of 36. There was no randomized allocation, and masking was listed as none. The record therefore describes a one-group investigation rather than a trial with a concurrent control arm. No like-for-like comparison between different dosing strategies or between treatment and control is available from this design.
The intervention was moxifloxacin 0.5%/dexamethasone 0.1% ophthalmic solution, identified as Vigadexa®. The study-eye schedule began 2 days before surgery with 1 drop, continued with 1 drop 4 times a day the day before surgery, and included 1 drop 60 minutes before the procedure on the operative day. These are the dosing details recorded; the registry does not report additional adherence measurements or exposure assessments.
The primary outcome was the mean aqueous-humor concentration of moxifloxacin, with a 95% confidence interval specified as its dispersion measure. The record places measurement on day 3, identified as the operative day. During cataract surgery, a 0.150 milliliter aqueous-humor sample was obtained, and moxifloxacin concentration was measured using a validated procedure with high performance liquid-spectrometry, as described in the outcome entry.
The primary population was defined per protocol by eligibility, receipt of all test-product doses, and completion of surgery with aqueous-humor sampling. Although enrollment is listed as 36, the numerical result and the number included in the endpoint analysis are not reported in the registry record. Start and primary-completion dates are listed as 2012-04 and 2012-08, and the overall status is completed. The registry record does not report a comparator, a masked assessment, or a separate statistical analysis entry.
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 reporting group includes all enrolled subjects.
Overall Study
| Stage | VIGADEXA |
|---|---|
| STARTED | 36 |
| COMPLETED | 31 |
| NOT COMPLETED | 5 |
Reasons for not completing this period:
| Reason | VIGADEXA |
|---|---|
| Protocol deviation | 3 |
| Adverse Event | 2 |
Analysis population for the primary outcome, as defined in the registry: Per protocol: All subjects who met inclusion/exclusion criteria, received all doses of the test product, and underwent cataract surgery with aqueous humor sampling.
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 reporting group includes all enrolled subjects who received all doses of the test product.
| Characteristic | Unit | VIGADEXA |
|---|---|---|
| Participants analysed | 35 | |
| Age Continuous | years | 71.2 (SD 10.4) |
| Sex: Female, Male: Female | Participants | 21 |
| Sex: Female, Male: Male | Participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Aqueous Humor Concentration of Moxifloxacin, measured over Day 3 (operative day).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | nanograms per milliliter |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean concentration of moxifloxacin in aqueous humor, expressed in nanograms per milliliter. It represents the amount of the antibiotic measured in the sampled fluid at the operative-day collection time after the specified preoperative dosing schedule. The sample was obtained during cataract surgery, with a recorded volume of 0.150 milliliter, and concentration was measured using a validated procedure with high performance liquid-spectrometry.
A concentration measure is used to describe drug exposure at a particular sampled site and time. In general, pharmacokinetic measurements can help characterize whether and how much of a drug is present in a target fluid after dosing. They do not, by themselves, establish a clinical benefit or describe the likelihood of a clinical event. The registry record does not state a target concentration, a threshold for interpreting the measured concentration, or a link between the concentration and a clinical outcome.
The endpoint is defined as a mean, with a 95% confidence interval as the accompanying measure of uncertainty. However, neither the numerical mean nor the confidence-interval limits are reported in the registry record. The record also does not report the number of participants contributing data to this endpoint, so its numerical precision cannot be assessed from the registry entry.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states the question and the planned form of the primary result, but it does not report the measured mean aqueous-humor concentration or the limits of its 95% confidence interval. As a result, the amount of moxifloxacin measured and the precision of that estimate cannot be evaluated from the record. No conclusion about the magnitude or variability of the measured concentration can be drawn from the information recorded.
The endpoint pertains to moxifloxacin concentration in a sampled fluid on the operative day after the listed dosing schedule. It is a pharmacokinetic measure, not a direct measure of a clinical outcome. The registry record does not report a clinical endpoint, a concentration threshold, or a relationship between the concentration and a clinical effect. A concentration result, even if available, would need to be interpreted within the limits of what that measure assesses.
The single-group design also constrains interpretation. It supplies no concurrent control group for estimating how the concentration would differ under another dosing regimen or in the absence of the combination product. The record lists no allocation and no masking. Thus, the registry entry cannot establish a comparative treatment effect. It describes one intervention schedule and a planned concentration measurement in the per-protocol population.
The listed enrollment is 36, but the endpoint population is defined by protocol adherence, eligibility, surgery, and sampling. The number who satisfied those conditions and contributed an endpoint is not reported in the registry record. Enrollment therefore should not be treated as the analysis population size. The record also contains no numerical endpoint summary, statistical test, or analysis entry from which to assess an observed effect or its uncertainty.
In general, a confidence interval communicates uncertainty around an estimated quantity: a narrower interval indicates greater precision, while a wider interval indicates less precision, under the assumptions of the analysis. Here, the registry identifies a 95% confidence interval as the dispersion measure but does not give its limits. Its precision cannot therefore be judged. No statistical significance question is addressed by the available endpoint description, and there is no reported contrast on which to base such an assessment.
The adverse-event entries are separate from the concentration endpoint. They list no serious adverse events among the group at risk, and list 2 affected in the other adverse-event category. The record does not provide event terms for those other events. These entries do not supply the missing concentration result and should not be used as a substitute for it.
9. Statistical Methods Explained
The primary measure is a mean of a continuous variable. A continuous outcome can take values across a measurement scale, rather than being limited to categories such as yes or no. Here the measured quantity is moxifloxacin concentration in aqueous humor, in nanograms per milliliter. A mean describes the central level of the measured values in the analysis population. It does not describe every individual measurement, and by itself it does not show how widely measurements vary.
What does the confidence interval add?
The registry specifies a 95% confidence interval as the dispersion measure for the mean. In general, a confidence interval gives a range of plausible values for the quantity being estimated, based on the observed data and the statistical method used. It helps readers assess precision: a more concentrated range indicates greater precision than a broad range. The interval does not replace the estimate, and its interpretation depends on the sampling and analysis assumptions. The registry record does not report the mean, either confidence-interval limit, or the method used to calculate the interval. Consequently, the precision of the primary estimate cannot be assessed.
What is the analysis population?
The endpoint description defines a per-protocol population. It includes subjects who met inclusion and exclusion criteria, received all test-product doses, and underwent cataract surgery with aqueous-humor sampling. This definition identifies which subjects were intended to contribute to the primary outcome; it is not the same as the enrollment figure. The record lists enrollment as 36 but does not report how many subjects met the endpoint population definition or had a concentration result included in the analysis. The handling of subjects who did not meet the per-protocol criteria is not reported in the registry record.
What does the design permit?
The study is listed as single group, with allocation not applicable and masking none. In general, a single-group study can describe outcomes observed after a specified intervention, but it does not provide a concurrent group for estimating a difference between interventions. Without a control group, the registry entry cannot separate the observed concentration under the stated schedule from what might have been measured under another schedule or without that regimen. The record does not report a comparative analysis.
The measurement is tied to a defined setting and time: an aqueous-humor sample was obtained during cataract surgery on day 3, identified as the operative day. The recorded sample volume was 0.150 milliliter. The outcome description says concentration was measured by a validated procedure using high performance liquid-spectrometry. The record does not provide further assay performance details, such as detection limits or measurement variability, so these cannot be assessed from the registry entry.
What cannot be inferred from an unreported result?
Because the numerical mean and interval are absent, readers cannot judge the estimated concentration, its variability, or its statistical precision. No recalculation from summary statistics is possible because no numerical summary statistics for the endpoint are recorded. The registry lists zero analyses, and does not report a statistical test or model for the primary outcome. The statistical analysis plan, if any, is not reported in the registry record.
The record's sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Such an illustration is not the study's observed power and does not establish that this single-group study was designed around a particular detectable effect. The record does not report a sample-size justification for the actual study, and the two-arm assumptions do not create a comparator that is absent from the design. No planning sample-size result is needed to interpret the primary outcome, and none can compensate for the missing numerical endpoint result.
In general, statistical precision depends on the amount and variability of usable data and on the analysis method. The record does not provide the endpoint analysis count, the distribution of concentrations, or details of the confidence-interval calculation. Those omissions prevent independent evaluation of the estimate's stability or assumptions. They do not alter the endpoint definition: it remains a mean concentration measured in the specified operative-day aqueous-humor sample among the described per-protocol population.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure and zero analyses. It does not report a multiplicity adjustment, a hierarchy of outcomes, or a prespecified strategy for controlling error across multiple statistical tests. The absence of an analysis entry means the registry record does not establish how the primary endpoint was analyzed or whether any additional analyses were conducted outside the record.
The primary population is defined per protocol, with eligibility, receipt of all test-product doses, surgery, and aqueous-humor sampling as criteria. The number of participants meeting that definition is not reported in the registry record. The record also does not describe an intention-to-treat population or another analysis population.
Missing-data handling is not reported in the registry record. In particular, the entry does not describe how missing concentration measurements, incomplete dosing, or failure to undergo sampling were handled. There is no reported account of the reasons for missing endpoint data or any method for addressing them. Without the endpoint analysis count and missing-data approach, the completeness of the primary outcome cannot be assessed. These are reporting gaps, not evidence that missing observations occurred or that a particular method was used.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| VIGADEXA | 0 | 36 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| VIGADEXA | 2 of 36 |
Most frequent non-serious adverse event terms
| Event term | Organ system | VIGADEXA |
|---|---|---|
| Hypertensive Crisis | Cardiac disorders | 2 of 36 |
The registry lists 36 at risk for serious adverse events and 0 affected in that category. It lists 36 at risk in the other adverse-event category and 2 affected. These are the safety counts recorded for the VIGADEXA group. The registry does not list any top serious-event terms. The deaths field has no numerical value, so the death count is not reported in the registry record.
The serious and other adverse-event categories should be read separately. The record does not name the other events, describe their severity, or provide details about timing or attribution. The counts alone do not establish whether an event was caused by the intervention. The registry entry also does not provide additional context about event collection or follow-up. These figures describe what is recorded for this study group; they do not provide a comparative safety estimate because no control group is described.
12. What the Result Does, and Does Not, Mean
This study addresses a focused pharmacokinetic question: the mean moxifloxacin concentration measured in aqueous humor at the operative-day sampling point after a specified preoperative schedule of Vigadexa®. The registry identifies the concentration unit, the sampling setting, the assay description, and the per-protocol population definition. It also identifies a 95% confidence interval as the intended measure of uncertainty around the mean.
The numerical result is not reported in the registry record. That omission means the actual concentration and its precision cannot be described. It is not appropriate to infer a value, characterize it as high or low, or judge whether it meets a target: no estimate, interval limits, or target concentration are recorded. The listed enrollment does not resolve this gap because the number included in the per-protocol endpoint analysis is also not reported.
The study's design is single group, with no comparator and no masking. Accordingly, the registry record does not estimate a difference between the listed regimen and another treatment or no treatment. It also does not establish that a measured concentration would lead to a particular clinical outcome. Concentration in aqueous humor is a pharmacokinetic measure; it is not itself evidence of clinical benefit or harm.
The safety entries describe 0 affected in the serious adverse-event category and 2 in the other adverse-event category, with 36 at risk in each category. The record does not give the other-event terms or a numerical death count. These observations are descriptive and do not establish comparative safety in the absence of a control group.
Overall, the registry record documents the study question and design but does not report the main numerical result needed to answer that question. Interpretation must remain limited to the planned measurement and the information recorded about the study group.
13. Why This Trial Matters Statistically
This study illustrates the distinction between a clinical outcome and a pharmacokinetic endpoint. The primary question concerns the mean concentration of moxifloxacin in aqueous humor at a specified time after dosing. Such a measurement can characterize drug exposure in a sampled fluid, while leaving separate the question of whether a clinical outcome changes. Keeping those questions distinct prevents a concentration measurement from being treated as a direct measure of patient benefit.
The record also shows why a clearly defined analysis population matters. The endpoint applies to subjects meeting eligibility and dosing criteria who underwent surgery with sampling, whereas the enrollment figure describes the study's registered enrollment. Without the number contributing to the endpoint, readers cannot determine how the analysis population relates to enrollment or assess the precision of the mean.
A confidence interval is useful for judging the precision of a mean, but only when its limits and the estimate are available. The registry identifies a 95% interval without reporting its numerical limits. This leaves the primary result uninterpretable quantitatively and demonstrates that an endpoint definition is not a substitute for reporting its estimate and uncertainty.
Finally, the single-group design makes the scope of inference important. It can describe the measurement associated with the stated schedule, but it does not provide a concurrent comparison. The registry record therefore supports a description of the intended investigation, not a comparative treatment conclusion. Together, these features underscore the importance of complete outcome reporting and design-aware interpretation in clinical research.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The central limitation for interpreting this record is that the primary numerical result is absent. The mean aqueous-humor concentration and its 95% confidence-interval limits are not reported in the registry record. The number of subjects included in that endpoint analysis is also not reported, so the precision and completeness of the primary result cannot be judged.
The single-group design provides no concurrent comparator, and masking is listed as none. The record cannot support a comparative estimate of concentration under a different regimen or a causal contrast between treatment strategies. The registry entry does not describe an analysis model, statistical test, confidence-interval calculation method, or a statistical analysis plan.
The endpoint is tied to the stated operative-day sampling point and does not describe a concentration profile across multiple time points. The registry does not report a target concentration or clinical outcome linked to the measured concentration. Further assay characteristics and the handling of missing measurements are not reported in the registry record.
The per-protocol definition is stated, but the number meeting it and the reasons any enrolled subjects might not have contributed are not reported. Safety information is also limited: the record does not list terms for the other adverse events, details of event timing or attribution, or a numerical death count. These reporting limitations restrict interpretation without establishing that any particular problem occurred.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Pharmacokinetic Evaluation of Moxifloxacin in Vigadexa® in Aqueous Humor Samples Following Preoperative Antibiotic/Steroid Dosing in Cataract Surgery Patients — NCT01859702.
- Registry record last updated 2013-08-07; status last verified 2013-06.
- Results first posted 2013-08-07.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01859702 is a completed Phase 4, single-group study sponsored by Alcon Research, with enrollment listed as 36 and cataract listed as the condition. It evaluated moxifloxacin 0.5%/dexamethasone 0.1% ophthalmic solution, identified as Vigadexa®, using the recorded preoperative study-eye dosing schedule.
The primary outcome was mean moxifloxacin concentration in aqueous humor on the operative day, with a 95% confidence interval specified. The outcome description records a 0.150 milliliter sample obtained during cataract surgery and measurement by high performance liquid-spectrometry. The numerical mean, confidence-interval limits, and number analyzed are not reported in the registry record.
The safety entry lists 0 serious adverse events and 2 affected in the other adverse-event category, with 36 at risk in each. No comparator is described.