Topcon 3D OCT-1000 Optical Coherence Tomography System: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Topcon 3D OCT-1000 Optical Coherence Tomography System (NCT00792259), a registered phase not stated study. The primary outcome is Precision and Agreement Between the Topcon 3D OCT 1000 and the Identified Predicate Device.

2. Clinical Question

This is a measurement-performance question, not a question about whether a treatment changes a patient’s health. The intended focus is the precision and agreement of thickness measurements, expressed in micrometers. The registry identifies the primary measure as a mean with standard deviation and gives a timeframe of 30 Minutes. It does not report the numerical means, standard deviations, agreement estimates, or precision estimates needed to judge the magnitude of measurement differences.

The record describes three participant categories in its arm descriptions: patients with retinal disease, patients without retinal disease, and normal subjects. It does not state that these categories were randomized or allocated as a like-for-like control comparison. The allocation method is not stated. Accordingly, the central question is whether device measurements correspond, not whether the participant groups differ in a causal treatment comparison.

3. Trial Design

The study is titled Topcon 3D OCT-1000 Optical Coherence Tomography System. Its official title describes a precision and agreement study of retinal and retinal nerve fiber layer thickness measurements. The sponsor is Topcon Medical Systems, Inc. The registry lists the study as completed, with a start of 2008-10 and primary completion of 2008-11. Enrollment is recorded as 48.

The brief description says the protocol compares retinal and retinal nerve fiber layer thickness measurements between the Topcon 3D-1000 and an identified predicate device. It also describes a comparison involving Zeiss Stratus OCT images: images collected and analyzed with the Zeiss Stratus OCT are compared with images collected with that system and imported into the Topcon 3D OCT-1000 StratusViewer for analysis. The record does not identify the predicate device by name or provide enough detail to reconstruct the measurement workflow.

Arm descriptions identify patients with retinal disease, patients without retinal disease, and normal subjects. The registry’s safety listings instead include Retinal Disease Eyes, Normal Subjects, and Glaucoma Subjects. The record does not explain this difference in labels or establish how these groups map to the listed arms. Allocation is not stated, and this is not described as a randomized comparison. The groups should therefore not be interpreted as randomized treatment and control groups.

The registry lists one outcome measure and 0 analyses. It does not report a statistical analysis plan, the number of measurements collected per participant, the handling of repeated measurements, or the exact comparison procedures. These omissions matter because measurements from the same person or eye may not be statistically independent. The posted record supports describing the intended design and its measurement goal, but not reconstructing the analysis that would be needed to quantify agreement.

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.

Overall Study

Reasons for not completing this period:

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: 20 Normal Subjects 15 Retinal Disease subjects 13 Glaucoma Subjects

6. Primary Endpoint

The registry lists the primary outcome as Precision and Agreement Between the Topcon 3D OCT 1000 and the Identified Predicate Device, measured over 30 Minutes.

The primary endpoint is described as precision and agreement between the Topcon 3D OCT-1000 and the identified predicate device. It concerns the thickness of the retinal nerve fiber layer and the full retina, with values expressed in µm. The registry identifies the parameter as a mean and the dispersion as a standard deviation, with a timeframe of 30 Minutes.

Thickness measurements are continuous quantities. Comparing devices can help assess whether they produce similar readings for the same anatomical feature. Precision concerns the consistency of measurements; agreement concerns how close measurements from different devices are. These are related but not interchangeable properties. A device can produce consistent readings yet differ systematically from another device, so a mean alone would not fully describe agreement.

The endpoint is relevant to evaluating measurement performance because it focuses on the device readings themselves rather than on a clinical outcome. The record does not state how precision or agreement was calculated, whether measurements were paired, or what summary statistics beyond mean and standard deviation were used. It also does not provide the actual endpoint values. The registry therefore defines the measurement target and units, but does not permit a quantitative conclusion about the observed agreement or precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean describe?

For a continuous measurement such as thickness in µm, a mean describes the average value in the observations included in an analysis. It can provide a compact description of measurements, but it does not show the full distribution of individual readings. The registry identifies the primary parameter as a mean. It does not report the numerical mean for either device or for any comparison.

When two devices measure the same feature, the mean measurement from each device is not necessarily the most informative comparison. If the same image or eye is assessed by both devices, the paired difference between readings can directly describe how far apart the devices are on those observations. If readings are not paired, a comparison of group means may be affected by differences in the observations being measured. The registry does not state whether or how device readings were paired. This is a general explanation of measurement-comparison methods, not a description of an analysis confirmed in the record.

What does a standard deviation describe?

A standard deviation describes the spread of observations around their mean. A smaller spread indicates that values are more tightly clustered in the analyzed data; a larger spread indicates greater variation. It does not, by itself, quantify agreement between devices. The record names standard deviation as the dispersion measure but gives no values. It also does not say whether the standard deviation describes readings from one device, differences between devices, or another set of measurements.

Precision is often assessed by examining repeated measurements and their variability. The interpretation depends on what was repeated: an image, a scan, an eye, an operator’s reading, or a measurement session. The registry does not report whether repeat measurements were obtained, or how precision was defined operationally. No precision estimate can be reconstructed from the endpoint description alone.

How is agreement different from association?

Agreement asks whether two methods give sufficiently similar values for the same measurement target. Association asks whether values tend to move together. Two methods can be strongly associated while differing systematically; for example, one could consistently read higher than the other. Therefore, a correlation by itself would not establish close agreement. This is a general statistical distinction. The registry does not identify a correlation analysis or any other specific agreement method.

Agreement analyses can summarize the average difference and the spread of individual differences. Confidence intervals can express uncertainty around an estimated quantity: a narrower interval indicates greater precision under the assumptions of the method, while a wider interval indicates more uncertainty. The registry record does not report confidence intervals or identify an interval-estimation procedure. It also does not state what degree of difference would be considered acceptable for this device comparison. Without a prespecified acceptable range, even a numerical estimate would need context to judge its practical importance.

What information is missing about the analysis?

The record lists 0 analyses and does not report a statistical analysis plan. In particular, it does not say how repeated readings or measurements from both eyes, if collected, would be handled. Observations from the same participant can be related rather than independent. Treating related observations as independent can make uncertainty appear smaller than it is. This is a general issue in study design, not evidence that the analysis in this study used an inappropriate method.

The record also does not describe adjustment for participant characteristics, how measurement failures or unusable images were handled, or whether any data transformations were used. It does not report whether the primary comparison was tested against a formal null hypothesis. A p-value, even if available, would not by itself show whether agreement was good enough for a particular use; the estimated difference and its uncertainty would also matter.

How should planning illustrations be understood?

Planning illustrations use the assumptions stated for them: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects defined as a stated fraction of the observed effect. They are planning calculations, not observed power. They do not establish what the study’s original sample-size justification was; that justification is not reported in the registry record. The record describes this study with three participant categories and does not state an allocation method, so the assumptions used for a planning illustration should not be mistaken for the actual study design.

Any calculation based on an observed effect depends on that estimated effect and on the stated assumptions. It should not be read as evidence that the study was designed around that effect, that the effect is unbiased, or that the study had a particular probability of detecting a finding. The record does not report an original sample-size calculation or a statistical plan that would resolve those questions.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure, described as precision and agreement for retinal nerve fiber layer and full retinal thickness. That single listing includes more than one anatomical measurement target, but the record does not explain whether each target was analyzed separately, whether there were additional device comparisons, or which result would be considered primary if multiple estimates were produced. It does not report a multiplicity adjustment or a strategy for controlling false-positive findings across analyses. Because the registry lists 0 analyses, the approach used cannot be established.

Multiplicity is a general concern when many outcomes, time points, subgroups, or comparisons are examined. The more results considered, the more important it can be to distinguish prespecified primary analyses from exploratory ones. The record does not report whether the measurement targets, subgroups, or comparisons were prespecified in a detailed analysis plan. No conclusion about the presence or absence of multiplicity adjustments can be drawn beyond noting that they are not reported in the registry record.

Missing-data handling is also not reported. The record does not state whether any participants lacked usable images or measurements, whether incomplete device pairs occurred, or how missing observations would be handled. It does not identify the analysis population used for the primary endpoint. Enrollment is recorded as 48, but the number contributing to an endpoint analysis is not stated. General statistical practice distinguishes enrolled participants from those included in a particular analysis; the record does not provide enough information to make that distinction for this study.

These omissions affect interpretation of both estimates and uncertainty. Without analysis-population definitions, missing-data procedures, and a prespecified analysis plan, readers cannot determine how much the reported population, if any, differs from the enrolled group or how sensitive results might be to exclusions. Since numerical endpoint results are not reported, those questions cannot be evaluated empirically from the registry record.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The safety listings report 0 serious adverse events and 0 other adverse events for Retinal Disease Eyes, Normal Subjects, and Glaucoma Subjects. The associated at-risk counts are 15, 20, and 13, respectively. These are the figures recorded for the listed safety groups; the record does not explain how the group labels correspond to the arm descriptions.

Zero reported events in a group means that the registry lists no events of that type for that group. It does not prove that the underlying risk is absent, and it does not establish that every possible event was detected or recorded. A zero count also does not indicate whether safety monitoring was complete or how events were defined. The registry does not report those details.

Deaths are listed as null, so deaths are not reported in the registry record; they should not be interpreted as a reported count of zero. The record gives no additional safety narrative or serious-event terms. These safety entries do not address the measurement-agreement question, and they should not be used to infer a clinical benefit or harm beyond the recorded event figures.

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

The study record matters as a description of a device-measurement question: whether the Topcon 3D OCT-1000 produces precise measurements and agrees with an identified predicate device for retinal nerve fiber layer and full retinal thickness. It also describes an image-analysis comparison involving Zeiss Stratus OCT and the Topcon StratusViewer. Those objectives concern measurement properties, not the effect of a treatment on a health outcome.

The record does not report numerical primary-endpoint findings. It therefore does not show the size or direction of differences between devices, the variability of those differences, or the uncertainty around an estimate. It cannot establish from the posted information whether agreement was close or whether measurements were sufficiently precise for any particular purpose. No threshold for acceptable agreement is reported.

Even a complete set of measurement estimates would need to be interpreted in light of how images and readings were collected, whether measurements were paired, how repeated observations were handled, and which analysis population was used. Those details are not reported. The record also does not provide the original sample-size justification or a statistical analysis plan. The planning assumptions described for illustrative calculations are not a substitute for those missing design details and are not observed power.

The enrollment of 48 and the listed group counts do not supply the missing endpoint results. Nor do the adverse-event listings answer the device-agreement question. The record indicates that the study was completed, but completion status alone does not establish a result. The appropriate conclusion is limited: the registry documents the intended comparison and some design and safety information, while the numerical evidence needed to assess measurement performance is not reported in the registry record.

13. Why This Trial Matters Statistically

Device measurement studies raise a statistical question that differs from the usual question in a treatment trial. The aim is to understand whether a measurement method gives sufficiently consistent and comparable readings, not whether one assigned treatment improves an outcome. For that reason, agreement and precision require summaries that describe differences and variability, rather than relying only on averages or association.

This study’s stated focus on retinal nerve fiber layer and full retinal thickness makes the distinction important. A device can produce repeatable readings yet have a systematic offset relative to another device. Conversely, average readings may appear similar while individual differences vary substantially. Clear reporting of the comparison method, paired observations, uncertainty, and clinically acceptable differences is needed to interpret measurement performance. These are general statistical considerations; the registry does not report the methods or results needed to apply them to this study.

The record also illustrates why a completed status and a defined primary question should not be mistaken for a reported answer. Although enrollment and the intended outcome are documented, the registry lists 0 analyses and no numerical primary-outcome estimates. Without those estimates, readers cannot assess the magnitude or precision of agreement. The study remains relevant as a protocol-level example of a measurement-comparison objective, but the registry record does not support a quantitative conclusion about the devices’ performance.

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 main limitation is that the registry record does not report numerical primary-outcome results. No means, standard deviations, agreement estimates, precision estimates, confidence intervals, or hypothesis-test results are available in the record. It therefore does not permit an empirical assessment of the stated primary objective.

Key design and analysis details are also absent. The predicate device is not named. The record does not state whether device readings were paired, whether measurements were repeated, how images were selected, or how readings from the same participant or eye were handled. It does not describe a statistical analysis plan, analysis populations, missing-data procedures, or the treatment of multiple measurement targets. These omissions prevent a detailed evaluation of how the intended comparisons were carried out.

The arm descriptions and safety-group labels differ: the arm descriptions include patients without retinal disease, while the safety listings include Glaucoma Subjects. The record does not explain the mapping between these descriptions. Allocation is not stated, and the groups are not described as a randomized comparison. This limits interpretation of between-group contrasts and makes it inappropriate to treat the listed categories as equivalent control groups.

Enrollment is recorded as 48, but the number of participants, images, or paired measurements contributing to each endpoint is not reported. The safety listing records no serious or other adverse events in the listed groups, but does not provide event definitions, monitoring details, or a reported death count. These limitations are specific to the available registry information and do not establish whether fuller study documentation contains additional detail.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Topcon 3D OCT-1000 Optical Coherence Tomography System — NCT00792259.
• Registry record last updated 2022-06-28; status last verified 2022-06.
• Results first posted 2015-06-17.
• 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.

18. Record Summary

The registry record identifies a completed precision and agreement study of the Topcon 3D OCT-1000 Optical Coherence Tomography System, sponsored by Topcon Medical Systems, Inc. It lists enrollment of 48, a start of 2008-10, and primary completion of 2008-11. The study’s stated objective is to compare retinal nerve fiber layer and full retinal thickness measurements with an identified predicate device. The protocol description also includes a comparison involving Zeiss Stratus OCT images analyzed in the Topcon StratusViewer.

The primary measure is described as a mean with standard deviation, in µm, at 30 Minutes. The registry lists 0 analyses and does not report numerical primary-outcome results, the predicate device’s name, the analysis plan, or missing-data procedures. Safety listings report 0 serious and 0 other adverse events for the stated groups; deaths are not reported in the registry record. The record documents the measurement question, but does not provide the numerical evidence needed to judge agreement or precision.