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 Low Cylinder Toric (NCT00732030), a non-randomized phase 4 study. The primary outcome is Uncorrected Distance Visual Acuity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00732030 |
| Phase | Phase 4 |
| Condition | Cataracts |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 26 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Alcon Research |
| Results posted | Yes |
2. Clinical Question
Population
People with cataracts were enrolled in a study of eyes with predicted residual corneal astigmatism between 0.75 and 1.03 diopters. The primary outcome description says data were collected for 29 eyes in 24 patients. The registry record lists enrollment as 26, and does not explain how that figure relates to the outcome population.
Intervention
Each enrolled eye received an AcrySof Toric Model SN60T3 intraocular lens, also described as AcrySof Toric T3. The study evaluated visual outcomes and patient satisfaction after implantation.
Comparator
There was no separate comparator group. The study is listed as single group and non-randomized, so its results do not provide a randomized, like-for-like comparison with another lens, treatment, or no intervention.
Primary question
The primary outcome was uncorrected distance visual acuity at 6 months, measured in logMAR. The record identifies the outcome as a mean with standard deviation, but does not report the numerical mean or standard deviation. Consequently, the registry record does not establish the observed level of visual acuity or the precision of that estimate.
The clinical question is descriptive: what visual acuity was recorded after implantation in this group, and how did patients report their satisfaction? The listed secondary outcome is a Patient Satisfaction Survey, but its numerical findings are not reported in the registry record. With no control group, the study cannot isolate the effect of the lens from other influences on the outcome. The record therefore supports a description of the study question and its measurement plan, but not a comparative estimate of benefit or harm.
3. Trial Design
The registry identifies this as a completed phase 4, non-randomized, single-group study with no masking. Alcon Research is listed as the sponsor. The study began in 2007-06, reached primary completion in 2009-03, and has completed status. Enrollment is listed as 26.
The intervention was a device: each enrolled eye received an AcrySof Toric Model SN60T3 intraocular lens. The study summary describes an evaluation of visual outcomes and patient satisfaction after implantation. No separate treatment arm or control group is listed. Because allocation was non-randomized and the design was single group, any observed outcome is an outcome in the treated study group, not a randomized contrast against an alternative.
The primary outcome was uncorrected distance visual acuity at 6 months, expressed in logMAR and specified as a mean with standard deviation. The outcome description states that data were collected for 29 eyes in 24 patients. This differs from the enrollment figure of 26, but the registry record does not explain the distinction or provide a participant flow account. The secondary outcome listed is a Patient Satisfaction Survey. Four outcome measures are recorded overall, but the registry record does not identify the other outcome measures in the registry record for this study description.
The record lists no posted analyses. It does not report the statistical analysis plan, the handling of multiple outcomes, or the analysis populations. Nor does it report why the study size was chosen. These absences limit assessment of how the reported outcomes, if available elsewhere, would relate to a prespecified analysis. The design can be described from the registry information, but details beyond it are not reported in the registry record.
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: During the preoperative exam, subjects were examined to ensure they met the inclusion/exclusion criteria. Only subjects who signed an informed consent and qualified to be in the study by meeting all inclusion/exclusion criteria were enrolled.
Overall Study
| Stage | AcrySof Toric T3 |
|---|---|
| STARTED | 26 |
| COMPLETED | 24 |
| NOT COMPLETED | 2 |
Analysis population for the primary outcome, as defined in the registry: Data was collected for 29 eyes in 24 patients.
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.
| Characteristic | Unit | AcrySof Toric T3 |
|---|---|---|
| Participants analysed | 26 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 7 |
| Age, Categorical: >=65 years | Participants | 19 |
| Sex: Female, Male: Female | Participants | 16 |
| Sex: Female, Male: Male | Participants | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Uncorrected Distance Visual Acuity, measured over 6 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | logMAR |
| Endpoint classification | Continuous Endpoint |
Uncorrected distance visual acuity measures how clearly a person can see at a distance without using corrective lenses for that measurement. The registry specifies measurement at 6 months after the study intervention and uses logMAR, the logarithm of the minimum angle of resolution, as the unit. Visual acuity is a functional outcome that can describe the visual status recorded after lens implantation.
The endpoint is specified as a mean, with standard deviation as the accompanying measure of dispersion. A mean gives a central summary across the measured eyes or participants; the standard deviation describes how spread out individual measurements are around that mean. These summaries answer different questions: the mean describes the group’s average measured acuity, while the standard deviation describes variation within the observed group. Neither, by itself, establishes a causal treatment effect.
As general context, logMAR is a scale for expressing visual acuity; lower values correspond to better acuity. Interpretation of an actual mean would require its numerical value and a clear understanding of the measurement population. The registry record identifies the unit and summary type but does not report the mean, standard deviation, confidence interval, or other numerical result. It therefore does not allow readers to assess the recorded acuity level or the precision of the estimate.
The outcome description refers to 29 eyes in 24 patients. Where more than one eye contributes data from a patient, observations may be related rather than independent. Whether and how the study accounted for this possibility is not reported in the registry record. This matters when estimating uncertainty because analyses that treat related observations as independent can give an inaccurate impression of precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary outcome is clearly named and timed: uncorrected distance visual acuity at 6 months, measured in logMAR and summarized as a mean with standard deviation. However, the numerical outcome itself is not reported in the registry record. No mean, standard deviation, confidence interval, test statistic, or p-value for the primary outcome is available in the study details. The registry record therefore does not support a quantitative statement about the level of acuity observed or the uncertainty around it.
The study enrolled a group that received the same named toric intraocular lens, without a separate comparator group. In this setting, an observed post-implantation outcome would describe the group’s measurement at the stated time. It would not, on its own, estimate what would have happened to comparable patients under another lens or without the intervention. Other influences, including characteristics of the patients and changes over time, cannot be separated from the intervention using a single-group observation alone.
The population counts also require care. Enrollment is listed as 26, whereas the primary outcome description says data were collected for 29 eyes in 24 patients. The registry record does not explain these counts, identify how many observations contributed to a numerical estimate, or describe losses to follow-up. The eye and patient counts are not interchangeable: eyes are measured units, while patients are people, and observations from two eyes of one person may be associated.
Patient satisfaction is listed as a secondary outcome, but its results are not reported in the registry record. Four outcome measures are recorded, although only the primary outcome and the satisfaction survey are identified in the registry entries. The registry record lists zero analyses, so no inferential results are available to assess. This does not establish that no analysis occurred; it means the record does not report analyses.
Safety information lists 24 people at risk for serious adverse events and zero affected. It also lists 24 at risk for other adverse events and zero affected. These are the figures recorded for the displayed group; they do not supply event-level detail or establish that every type of harm was assessed and absent. Deaths are not reported in the registry record. Overall, the posted information identifies the design, endpoint, and safety counts, but it is not sufficient to judge the magnitude or precision of the visual acuity outcome.
9. Statistical Methods Explained
The record specifies a continuous primary outcome summarized by a mean and standard deviation. A continuous measure can take values across a scale rather than belonging to a set of categories. Reporting a mean is one way to describe the center of the observed measurements. The standard deviation describes how much individual measurements vary around that center. They are descriptive summaries; neither alone answers whether an outcome differs from a comparator or what caused the observed values.
What would a confidence interval add?
As a general statistical concept, a confidence interval expresses uncertainty about an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater precision for that estimate, while a wider interval indicates less precision. It is not a range that guarantees where every individual measurement lies. The registry record does not report a confidence interval for the primary outcome, so the precision of a mean cannot be evaluated from the posted information.
What does a single-group design allow?
A single-group study can describe outcomes in the group that received the intervention. If measurements were reported, the mean could summarize the observed acuity at the stated time. A single-group outcome does not provide a concurrent comparison that accounts for what would have happened under an alternative. Changes over time, participant characteristics, and other factors may contribute to an observed result. This is a general limitation of interpretation, not evidence that any particular factor affected this study.
The study is also listed as non-randomized and unmasked. Random allocation, when used, helps create comparable groups by chance; no such comparison is listed for this study. Masking can reduce some opportunities for expectations to influence measurement or reporting, but the registry lists no masking. The record does not describe who knew the intervention assignment or what procedures were used to standardize outcome assessment, so those details are not reported in the registry record.
How should the eye and patient counts be understood?
The outcome description states that observations were collected for 29 eyes in 24 patients, while total enrollment is listed as 26. An eye-level measurement and a patient-level count refer to different units. If multiple eyes from one patient contribute measurements, the values may be correlated. As general statistical context, treating correlated observations as wholly independent can understate uncertainty. The registry record does not say whether one or both eyes per patient were analyzed, whether within-patient dependence was addressed, or how the enrollment figure relates to the outcome population.
What can be inferred from the analysis record?
The record lists zero analyses. The numerical result for the primary endpoint is also not reported in the registry record. There is consequently no posted estimate to interpret and no reported inferential procedure to evaluate. The planned analysis, any adjustment for baseline measurements, the treatment of missing observations, and the handling of outliers are not reported in the registry record. These are distinct decisions that can affect an estimate or its uncertainty; they should not be presumed from the endpoint description alone.
Four outcome measures are recorded, but only the primary visual acuity outcome and the Patient Satisfaction Survey are identified in the registry entries. As general context, when several outcomes or repeated tests are examined, the chance of at least one apparently unusual result can increase if no adjustment or prespecified hierarchy is used. Whether multiplicity was considered, and whether any adjustment was planned, is not reported in the registry record. No claim about adjusted or unadjusted significance can be made from the posted information.
What do planning illustrations mean?
Sample-size calculations are planning tools, not observed findings. The stated planning assumptions use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as fractions of an observed effect. Those assumptions describe an illustration rather than the design of this single-group study. The assumptions also refer to a two-arm comparison, which is not the listed trial design. Any such calculated sample sizes should not be read as observed power or as evidence that the study detected an effect. The trial’s own sample-size justification is not reported in the registry record.
For a continuous outcome, planning calculations depend on assumptions about the effect to detect and the variability of measurements. If those inputs are uncertain, the resulting planning estimate is uncertain too. Because the primary numerical result and its dispersion are not reported in the registry record, the observed outcome cannot be used to evaluate those inputs. No additional calculation or reconstruction should be treated as the sponsor’s analysis; the registry record lists no analyses.
10. Confidence Intervals for Each Arm
No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.
| Arm | Participants | Mean | Standard deviation | 95% CI for the mean |
|---|---|---|---|---|
| AcrySof Toric T3 | 24 | 0.090 | 0.140 | 0.031 to 0.149 |
R code and output
arm <- c("AcrySof Toric T3")
n <- c(24)
m <- c(0.09)
sp <- c(0.14)
sd <- sp # posted standard deviations
for (i in seq_along(n)) {
se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}
CARM AcrySof Toric T3 24 0.090 0.140 0.031 0.14911. Multiplicity, Missing Data and Analysis Populations
The registry records four outcome measures. It identifies uncorrected distance visual acuity at 6 months as the primary outcome and lists a Patient Satisfaction Survey as a secondary outcome. The other two measures are not identified in the registry record. The record does not report whether outcomes were tested in a prespecified hierarchy, whether any multiplicity adjustment was planned, or whether analyses of multiple time points or subgroups were performed. As general context, assessing many outcomes can increase the chance of an apparently noteworthy finding by chance if the analysis does not account for the number of comparisons. No conclusion about multiplicity-adjusted findings is possible from the posted information.
The registry lists zero analyses and does not report the numerical primary outcome. It also does not report an analysis plan, a definition of the analysis population, or rules for excluding observations. The primary outcome description gives data for 29 eyes in 24 patients, while enrollment is listed as 26. The relationship among these counts is not explained.
Missing-data methods and the amount or pattern of missing outcome data are not reported in the registry record. It is therefore unclear whether all enrolled participants or eyes contributed to each outcome, how incomplete measurements were handled, or whether follow-up differed across the group. The record also does not say whether the analysis accounted for possible dependence between eyes from the same patient. These are important details for interpreting both the center and precision of an estimate, but they cannot be inferred from the outcome definition.
12. 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 |
|---|---|---|---|
| AcrySof Toric T3 | 0 | 24 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| AcrySof Toric T3 | 0 of 24 |
The serious adverse event figures list 24 at risk and zero affected in the AcrySof Toric T3 group. The other adverse event figures also list 24 at risk and zero affected. These counts describe what the registry record reports for the listed group; they are not a comparison against a control group.
A zero affected count means no affected participants are recorded in those displayed figures. It does not, by itself, establish that no adverse event of any kind occurred, that all possible events were collected, or that the intervention has no risk. The serious and other adverse event categories are reported separately, and the registry record does not provide event-level descriptions for the other adverse events. No top serious event terms are listed. Deaths are not reported in the registry record.
The number at risk is a denominator for interpreting the affected count, but the record does not describe follow-up duration for safety, event ascertainment procedures, or whether all participants were assessed for the same length of time. The figures should therefore be read narrowly as registry-reported counts rather than as a complete account of safety over time. With no comparator group, they cannot show whether event occurrence differed from that under another treatment.
13. What the Result Does, and Does Not, Mean
The registry record establishes that the study was a completed, single-group evaluation of the AcrySof Toric Model SN60T3 intraocular lens in people with cataracts. Its primary outcome was uncorrected distance visual acuity at 6 months, measured in logMAR and specified as a mean with standard deviation. The record also lists a patient satisfaction survey and reports safety counts for the study group.
It does not report the numerical primary outcome, its standard deviation, a confidence interval, or an analysis result. As a result, readers cannot determine the observed mean acuity or how precisely it was estimated from the registry record. Satisfaction results are likewise not reported. The listed zero affected counts for serious and other adverse events are descriptive registry figures, not proof that no risks exist or that all events were captured.
The design does not include a separate comparator group, and it is listed as non-randomized and unmasked. Any observed measurement in this group would not, by itself, establish that the intervention caused that outcome or show how it compares with another lens. The record does not report the analysis methods needed to assess uncertainty, possible dependence between eyes, missing observations, or multiplicity across outcomes.
These limits do not erase the value of a clearly specified outcome or the descriptive information in the record. They define what can be concluded from it. The available information describes the intended clinical question and study structure, but it does not provide enough numerical outcome evidence for an estimate of visual acuity or a comparative treatment effect. The study’s results should not be characterized as showing that the lens works or does not work on the basis of the information reported in the registry record.
14. Why This Trial Matters Statistically
This study illustrates why the design and the unit of analysis matter when interpreting clinical measurements. The primary outcome is measured in eyes, while enrollment and patient counts refer to people. The record says data were collected for 29 eyes in 24 patients and lists total enrollment as 26, but does not explain the relationship among these counts. If two eyes from one person contribute, their measurements may be related. A valid uncertainty estimate should account for the analysis unit and any relevant dependence; whether this was done is not reported in the registry record.
The study also makes the difference between a descriptive outcome and a treatment comparison clear. A single-group study can describe a measurement after intervention, but it cannot provide the same kind of evidence as a randomized comparison. The lack of a comparator limits causal interpretation regardless of whether an observed value appears favorable or unfavorable. Here, even the numerical primary result is not reported in the registry record, so the descriptive outcome cannot be assessed quantitatively.
Finally, the record distinguishes outcome specification from statistical reporting. It identifies the endpoint, unit, summary type, and timeframe, but does not report the result, analysis plan, missing-data approach, or multiplicity handling. Such details are needed to understand not only the direction and magnitude of an estimate, but also its precision and robustness. The record is therefore useful for identifying what was studied while also showing the limits of conclusions possible from the posted statistical information.
15. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation for interpreting this trial record is the absence of numerical results for the primary endpoint. Although the outcome is specified as mean uncorrected distance visual acuity in logMAR at 6 months, the mean and standard deviation are not reported in the registry record. No confidence interval or test result is listed, so neither the size nor precision of the observed outcome can be assessed.
The study has no listed comparator group and is described as non-randomized and unmasked. Consequently, it cannot provide a randomized comparative estimate, and observed outcomes cannot be attributed to the intervention alone. The record does not describe how visual acuity was assessed or whether outcome assessment procedures were standardized.
The participant and measurement counts are not reconciled: enrollment is listed as 26, while the primary outcome description refers to 29 eyes in 24 patients. Follow-up completeness, the number of observations included in analysis, and the handling of any missing measurements are not reported in the registry record. Nor is it reported whether both eyes could contribute from a participant or how any within-patient correlation was handled.
Four outcome measures are recorded, but only the primary endpoint and satisfaction survey are identified in the registry entries. Multiplicity procedures, analysis populations, and the statistical analysis plan are not reported. The safety figures give counts but do not describe event ascertainment or follow-up duration; deaths are not reported in the registry record. These limitations restrict interpretation to the study structure and the specific registry figures, rather than supporting a broad assessment of efficacy, comparative safety, or precision.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Low Cylinder Toric — NCT00732030.
- Registry record last updated 2010-04-07; status last verified 2010-03.
- Results first posted 2010-04-07.
- 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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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
NCT00732030 is a completed phase 4, non-randomized, unmasked, single-group study sponsored by Alcon Research. The study evaluated the AcrySof Toric Model SN60T3 intraocular lens in people with cataracts. Enrollment is listed as 26; the study began in 2007-06 and reached primary completion in 2009-03.
The primary outcome was uncorrected distance visual acuity at 6 months, measured in logMAR and specified as a mean with standard deviation. The outcome description refers to 29 eyes in 24 patients. The numerical primary result and the Patient Satisfaction Survey findings are not reported in the registry record. Four outcome measures are recorded, and zero analyses are listed.
The record reports zero affected for serious adverse events among 24 at risk and zero affected for other adverse events among 24 at risk. Deaths are not reported in the registry record. The single-group design offers no randomized comparator, and the registry information does not report the analysis plan, missing-data methods, or numerical outcome estimates.