Fluocinolone Acetonide Intravitreal Inserts in Geographic Atrophy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Fluocinolone Acetonide Intravitreal Inserts in Geographic Atrophy (NCT00695318), a randomized phase 2 study. The primary outcome is Change From Baseline in Size of Geographic Atrophy.

2. Clinical Question

The clinical question concerns the change in geographic atrophy size, recorded in mm3/year, for two active-dose groups versus sham. The registry's brief summary describes a safety and efficacy comparison of treatment in one eye with sham in the fellow eye. The primary outcome is titled “Change From Baseline in Size of Geographic Atrophy,” with a 24-month timeframe. The posted outcome values are means with standard deviations for the sham and active-treatment groups at each dose.

The study is described as randomized, and its official title calls it a fellow-eye comparison. A fellow-eye setup can account for some differences between people because each participant contributes an eye to each condition. However, the registry does not report the method used to analyze the within-participant relationship between eyes. It also lists a parallel model. These details establish the intended comparison but do not reveal the statistical model used for the outcome.

The registry record does not report an inferential treatment comparison, such as an estimated between-eye effect with a confidence interval or a hypothesis-test result. Therefore, the posted means describe the observed outcome values but do not quantify the precision of a treatment contrast or establish how compatible those data are with different possible effects.

3. Trial Design

This was a phase 2 randomized study sponsored by Alimera Sciences. The registry lists the study as quadruple-masked and assigns it a parallel model. The official title describes it as double-masked, and also identifies a randomized, fellow-eye comparison. The record thus contains different masking descriptions; the exact masking arrangements are not reported in the registry record.

The study concerned participants with bilateral geographic atrophy due to age-related macular degeneration. The brief summary describes active treatment in one eye and sham treatment in the fellow eye. Two dose groups are reported: 0.2 µg/Day and 0.5 µg/Day. The posted primary outcome includes a sham group and an active-treatment group at each dose. The registry reports enrollment of 17 participants, while the outcome entries list 8 participants for each 0.2 µg/Day arm and 6 for each 0.5 µg/Day arm. Reasons for the outcome counts and the relationship between those counts and all enrolled participants are not reported.

The recorded study start was 2008-12, and primary completion was 2013-10. Its status is terminated. The reason for termination, the timing of termination relative to follow-up, and whether all planned assessments were completed are not reported in the registry record. The registry reports one outcome measure and no posted secondary outcomes. It lists no analyses.

Although randomization and a fellow-eye comparison are described, details such as the allocation procedure, allocation ratio, randomization unit, and handling of the paired eye data are not reported. The record does not give a statistical analysis plan or a sample-size justification. The design labels and outcome summaries are therefore not enough to reconstruct the planned or performed analysis.

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:

Analysis population for the primary outcome, as defined in the registry: Patients received either a 0.2µg/Day or 0.5 µg/Day treatment in the study eye and a sham treatment in the fellow eye.

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: Patients received either the 0.2µ/day or 0.5µ /day dose as well as a sham injection in the fellow eye. The total number of subjects enrolled/analyzed was 17.

6. Primary Endpoint

The registry lists the primary outcome as Change From Baseline in Size of Geographic Atrophy, measured over 24 months.

The primary endpoint is change from baseline in the size of geographic atrophy, with the unit recorded as mm3/year and a timeframe of 24 months. Geographic atrophy is the condition being assessed in this study; tracking change in its size provides a quantitative way to describe how the measured lesion changes over follow-up. A continuous endpoint retains the scale of the measurement rather than reducing each participant's result to a category such as improved or not improved.

The registry defines the reported summary as a mean and gives a standard deviation for each arm. The mean describes the central value of the observations in an arm. The standard deviation describes how dispersed the individual observations are around that mean. Neither summary, by itself, gives the uncertainty in a between-group treatment estimate. That would require an analysis comparing the groups and an uncertainty measure such as a confidence interval.

The outcome's unit is reported as mm3/year. The registry does not further describe the measurement method, the sign convention for change, or how the annualized unit was derived from assessments over the 24-month timeframe. Those details are not reported in the registry record. Accordingly, the posted values can be described as the recorded means and standard deviations, but their clinical interpretation is limited by the absence of measurement and analysis details.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The posted endpoint is continuous and summarized by arm using a mean and standard deviation. The registry does not report the inferential method used for the primary outcome; in fact, it lists no analyses. The explanations below describe general statistical concepts relevant to interpreting this type of endpoint and this study design, not methods confirmed as used by the investigators.

What do the mean and standard deviation describe?

In general, the mean is the arithmetic average of observed measurements in a group. It gives a compact description of the group's center, but it does not show whether individual observations are close to that center or widely dispersed. The standard deviation describes the spread of observations around the mean. A larger standard deviation indicates greater variability among the recorded measurements, not necessarily greater uncertainty in the mean itself.

The standard deviation is not a confidence interval and is not a direct estimate of the treatment effect. It describes variation among observations, whereas a confidence interval describes uncertainty around an estimated quantity, such as a mean or a contrast between treatment groups. A confidence interval for a treatment contrast would require a specified analysis and information about the data structure. No such interval is posted for this endpoint.

Why is the fellow-eye structure important?

In general, when two eyes from the same participant are compared, the measurements may be related because they share characteristics of that person. A paired analysis uses the within-participant relationship rather than treating each eye as if it came from a different, unrelated person. Accounting for pairing can affect the estimated uncertainty of a contrast. The registry describes treatment in one eye and sham in the fellow eye, but does not report the paired outcomes, their correlation, or the analysis approach. The arm means and standard deviations alone cannot reconstruct the paired comparison.

The registry also labels the model as parallel. The record does not explain how that label relates to the fellow-eye description or how the allocation and analysis were implemented. It is therefore not appropriate to infer the statistical model from the design description alone.

What would an inferential comparison add?

In general, an inferential analysis would estimate a contrast between active treatment and sham and quantify uncertainty in that contrast. A confidence interval can show a range of effect values reasonably compatible with the data under the analysis assumptions. A hypothesis test can assess the compatibility of the data with a specified null hypothesis, but a p-value does not measure the size or clinical importance of an effect. Neither an estimate, a confidence interval, nor a p-value is reported for the primary endpoint in the registry record.

The registry's sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. These are assumptions for a planning illustration, not evidence of the trial's original design rationale or an observed measure of power. The record does not report a trial-specific sample-size justification. No calculated planning values are stated in the primary results, and such illustrations should not be read as proof that the study was adequately powered.

Why can variability and small groups matter?

In general, an estimate based on a small number of observations can be sensitive to individual measurements. The standard deviations in the posted arms describe the observed spread, while the limited arm counts constrain how precisely a group mean or treatment contrast can be estimated. A small sample does not make a result automatically invalid, but it makes transparent uncertainty reporting particularly important. Here, the absence of a reported contrast and confidence interval prevents direct assessment of that uncertainty.

Over-dispersion is a general concern when data vary more than a model assumes. If a statistical model understates variability, its uncertainty estimates can be too narrow and its tests can be misleading. The registry does not report a model or evidence about over-dispersion for this outcome, so no claim can be made about whether it was present or how it was handled. The endpoint is described as continuous, and no distributional diagnostics or transformations are reported.

What is not documented?

The analysis method, handling of paired observations, covariate adjustment, missing-data method, and analysis population are not reported in the registry record. There is also no posted interim analysis information or statistical analysis plan. These omissions mean that the observed summaries cannot be connected to a documented inferential procedure, and the risk of bias from missing outcome data cannot be evaluated from the record. General statistical principles explain what would be relevant to an analysis, but they do not establish which procedures this trial used.

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.

R code and output

arm <- c("A, 2, I Sham", "A, 2, I 0.2 µg/Day", "A, 2, II Sham", "A, 2, II 0.5 µg/Day")
n   <- c(8, 8, 6, 6)
m   <- c(2.513, 2.758, 2.599, 2.562)
sp  <- c(1.5318, 1.783, 2.4005, 1.9685)
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  A, 2, I Sham  8  2.513  1.532  1.232  3.794
CARM  A, 2, I 0.2 µg/Day  8  2.758  1.783  1.267  4.249
CARM  A, 2, II Sham  6  2.599  2.401  0.080  5.118
CARM  A, 2, II 0.5 µg/Day  6  2.562  1.968  0.496  4.628

11. Multiplicity, Missing Data and Analysis Populations

The registry reports one primary outcome measure and no posted secondary outcomes. It lists no analyses. A multiplicity plan, including whether or how the two dose comparisons were handled together, is not reported in the registry record. In general, when more than one comparison is assessed, the chance of a false-positive finding across the set can depend on the testing strategy. Without a reported analysis plan or inferential results, the impact of multiplicity cannot be assessed.

The registry does not describe missing-data handling, reasons for missing outcome measurements, or whether any participants were excluded from the primary analysis. Enrollment was 17, while the posted primary-outcome arms list 8 participants per arm at 0.2 µg/Day and 6 per arm at 0.5 µg/Day. The relationship between these counts and the enrolled population is not explained. These counts alone do not establish why observations are absent or whether the missingness could affect the results.

The record does not identify an intention-to-treat, per-protocol, or other analysis population. It also does not report sensitivity analyses that might assess how assumptions about missing observations affect estimates. Such methods are general tools for evaluating robustness; they cannot be presumed to have been used. Details of interim analyses, stopping criteria, and a prespecified statistical analysis plan are not reported in the registry record.

Because analysis populations and missing-data methods are undocumented, the arm summaries should be read as posted descriptive results rather than as a complete account of every enrolled participant's outcome. The absence of reported secondary outcomes or analyses also limits assessment of selective reporting.

12. 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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cataract operation (30.0%), anaemia (14.3%), myocardial infarction (14.3%), oesophageal achalasia (14.3%), sepsis (14.3%).

The registry reports serious adverse event counts for several exposure groups. For the sham injection group, 3 of 17 participants at risk were affected. For the 0.2 ug/Day group, 3 of 10 at risk were affected; for the 0.5 ug/Day group, 2 of 7 were affected. It also reports combined groups: 3 of 10 affected among those listed for 0.2 ug/Day plus sham injection, and 5 of 7 affected among those listed for 0.5 ug/Day plus sham injection. These are the record's group-specific counts; the record does not explain how the groups relate to one another or whether participants appear in more than one category.

The listed serious adverse event terms include Cataract operation at 30.0%, and Anaemia, Myocardial infarction, Oesophageal achalasia, Sepsis, and Dehydration at 14.3% each. The denominator and counting method for these listed percentages are not reported in the registry record. The record does not provide enough detail to attribute events to a treatment or compare event risk between treatment conditions. Death counts are not reported in the registry record.

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

The primary results establish what the registry reports descriptively: arm-level means and standard deviations for change from baseline in geographic atrophy size at 24 months. They show the observed values for sham and active treatment at each dose. They do not supply a statistical estimate of either treatment contrast, a confidence interval, or a hypothesis-test result. The record therefore does not show the precision of an active-versus-sham comparison.

The study's fellow-eye description means that the eyes belong to the same participants, making paired analysis an important consideration in general. Yet the registry does not document whether the posted summaries arise from a paired analysis or another method. The results also do not describe missing outcome data or the analysis population. These omissions limit what can be inferred from the reported arm summaries.

The study is listed as terminated, but the reason and consequences for follow-up are not reported. The record does not say whether termination resulted from a planned decision, operational circumstances, or another reason; no explanation should be inferred. Likewise, a phase 2 label and an enrollment of 17 do not by themselves establish the study's intended precision or the evidential weight of its results.

These data should not be taken as proof that active treatment is better, worse, or equivalent to sham. Establishing equivalence or lack of a meaningful difference requires an appropriate design and a prespecified margin, as well as an analysis whose uncertainty is reported. Such information is not reported in the registry record. The posted values support a limited descriptive reading, not a definitive treatment conclusion.

The same caution applies to safety. The record gives affected-participant counts and listed serious-event terms, but does not provide a causal assessment or enough detail to make direct treatment-risk comparisons. The counts are a description of reported events, not a determination that the treatment caused them.

14. Why This Trial Matters Statistically

This trial is statistically notable because its registry description combines a fellow-eye comparison with a model classified as parallel. A fellow-eye design generally creates paired observations, since each participant contributes an eye to active treatment and an eye to sham. Analyses of paired measurements need to account for the dependence between those eyes. The record does not report whether or how that dependence was handled, so the design description cannot be translated into a verified analysis.

The trial also illustrates why descriptive summaries and inferential results answer different questions. Means and standard deviations provide information about observed arm-level outcomes and variability. They do not by themselves estimate the uncertainty of the within-participant treatment contrast. Without a reported contrast and confidence interval, readers cannot assess the precision of the primary comparison using the registry record.

Small outcome counts heighten the importance of clear reporting. The primary-outcome arms list 8 participants for each arm at 0.2 µg/Day and 6 for each arm at 0.5 µg/Day, while enrollment is 17. The record does not explain the difference. Reporting the analysis population, missingness, and paired-data method would help readers understand how the observations contribute to the result.

Finally, the study is marked terminated, but no reason is recorded. Combined with the absence of posted inferential analyses and a documented statistical plan, this leaves key questions about completeness and interpretation unanswered. These are reporting limitations, not evidence of a particular outcome or motive. The trial's posted results are useful as a record of descriptive findings, while demonstrating why treatment estimates, uncertainty, analysis methods, and participant flow are needed for statistical interpretation.

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 primary-outcome results are limited to group means and standard deviations. No inferential analyses are listed, and the registry does not report treatment contrasts, confidence intervals, p-values, or a statistical model. The description of treatment in one eye and sham in the fellow eye makes the paired relationship important, but the paired differences and within-participant correlation are not reported.

The posted arm counts are smaller than the enrollment count, and the reasons are not given. The analysis population, completeness of follow-up, missing-data mechanisms, and missing-data methods are not reported in the registry record. It is therefore unclear how representative the analyzed observations are of all enrolled participants.

The record identifies the study as terminated but does not give a reason or state whether planned follow-up was completed. It reports no secondary outcomes and no analyses. A statistical analysis plan, sample-size justification, multiplicity approach, interim-analysis details, and stopping rules are not reported. The registry's general planning assumptions do not establish the trial's original design rationale.

There is also a difference in the record's masking descriptions: the structured design information says quadruple masking, while the official title says double-masked. The registry does not explain the discrepancy or specify who was masked. The model is listed as parallel even though the study description emphasizes a fellow-eye comparison. These record details are not enough to resolve how the trial was implemented.

For safety, the registry gives serious-event counts and terms but does not report attribution, event timing, or the denominator for the listed percentages. Death counts are not reported in the registry record. Together, these limitations constrain interpretation of both the efficacy summaries and safety information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Fluocinolone Acetonide Intravitreal Inserts in Geographic Atrophy — NCT00695318.
• Registry record last updated 2015-05-29; status last verified 2015-05.
• Results first posted 2015-05-29.
• 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.

19. Record Summary

NCT00695318 is a phase 2 randomized study sponsored by Alimera Sciences of fluocinolone acetonide inserts for geographic atrophy due to age-related macular degeneration. The record describes active treatment in one eye and sham in the fellow eye, with 0.2 µg/Day and 0.5 µg/Day dose groups. It lists quadruple masking and a parallel model, while the official title says double-masked and describes a fellow-eye comparison.

The study enrolled 17 participants, began in 2008-12, had primary completion in 2013-10, and is listed as terminated. Its primary outcome was change from baseline in geographic atrophy size, measured in mm3/year over 24 months. The registry posts means and standard deviations for sham and active-treatment arms at both doses, but lists no analyses. The reason for termination, inferential results, analysis methods, and missing-data handling are not reported in the registry record.