No Drop Post-Op Cataract Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for No Drop Post-Op Cataract Surgery (NCT03864133), a na phase 4 study. The primary outcome is Best Corrected Visual Acuity (BCVA) (Pre-op).

2. Clinical Question

This distinction matters when interpreting the clinical question. The study description frames intraoperative infusion as an approach used instead of topical NSAID drops around surgery, but the design does not provide a like-for-like comparison between those approaches. With one listed treatment group, the registry can describe measurements among participants receiving the infusion; it cannot, on its own, separate changes associated with the intervention from changes that might occur over time or for other reasons.

The record is marked completed, and its enrollment is 94. Those details describe the registered study, not the amount of evidence available for the primary clinical question: the numerical baseline measure and comparative postoperative results are not reported in the registry record.

3. Trial Design

This is a Phase 4, single-group study recorded as completed. The registry lists enrollment of 94 and gives Wake Forest University Health Sciences as the sponsor. The recorded study start is 2019-07-08, and the primary completion date is 2021-06-30. These dates describe the registry record; they do not supply the timing or completeness of individual participants’ follow-up.

The intervention is Omidria, described as phenylephrine/ketorolac at 1%/0.3%, administered to all enrolled participants during cataract surgery. The brief study description says participants receive the infusion instead of topical NSAID drops before and after surgery. But no separate group receiving topical drops, placebo, or another treatment is listed. The allocation field is recorded as NA, the model is single group, and masking is none. The record therefore does not describe a randomized, masked, like-for-like comparison.

The study title refers to retinal thickness and macular edema. The listed primary outcome, however, is best corrected visual acuity before surgery, at baseline, recorded as a mean with standard deviation in LogMar. The record also notes that best vision is tested with lens correction using Snellen Charts. The registry lists 7 outcome measures but no analyses. Specific postoperative endpoint values, follow-up timepoints, and analytic populations are not reported in the registry record.

A single-group design may describe what was measured in people receiving the intervention, but it has no concurrent control group in this record to serve as a comparison for treatment effects. Consequently, the design cannot by itself establish whether a change after surgery differs from what would have occurred without the intervention. The registry does not report a protocol rationale for this design, a sample-size justification for the trial, or a statistical analysis plan.

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

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Best Corrected Visual Acuity (BCVA) (Pre-op), measured over Baseline.

Best corrected visual acuity (BCVA) is a measure of how well a person can see when the test uses lens correction. The registry describes testing with Snellen Charts and records the primary measure in LogMar. In general, LogMar expresses visual acuity on a logarithmic scale; lower values generally correspond to better acuity. That general interpretation does not substitute for a trial result, and the record does not give a BCVA value.

The listed timeframe is baseline, identified as preoperative. A baseline assessment can describe participants’ starting status and can be useful for interpreting later measurements if those measurements and an appropriate analysis are available. It is not, by itself, evidence of a postoperative effect. The registry’s primary outcome listing therefore does not directly report the study title’s retinal-thickness or macular-edema question, nor does it provide a post-surgery BCVA comparison.

Visual acuity is clinically interpretable because it measures vision with correction, but an endpoint’s relevance depends on when it is measured and how it is analyzed. A baseline mean and standard deviation, if reported, would describe the group’s starting distribution; neither is included in the registry record. Postoperative BCVA results, the measurement schedule, and any planned method for comparing follow-up with baseline are also not reported in the registry record. No treatment-effect estimate or precision interval for this endpoint can therefore be interpreted from the recorded information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

In general, a single-group study records outcomes among participants who receive the same intervention. It can describe the participants’ observed measurements, including how those measurements vary. If measurements are collected at different times, an analysis can describe change over time. But a within-group change is not equivalent to a treatment-versus-control effect. Without a concurrent comparison group, the observed course cannot be cleanly distinguished from changes that might have occurred without the intervention.

That distinction applies to this record because the model is single group, the arm description says all enrolled participants receive Omidria, and no comparator arm is listed. The study summary mentions topical NSAID drops as the alternative to the infusion, but no group receiving those drops is recorded. A direct contrast between the two approaches is therefore not available from the registered design. The allocation entry is NA; it does not provide evidence of random allocation. Masking is recorded as none, so the record does not describe masked assessment or treatment.

What does a mean and standard deviation describe?

The primary measure is continuous and is specified as a mean with standard deviation. In general, the mean describes the center of a set of measurements, while the standard deviation describes their spread around that center. Together they can convey a group’s typical measured level and variability, subject to the distribution and measurement context. They do not alone show a treatment effect. A comparison, an estimate of uncertainty, and an appropriate analysis are needed to answer a comparative question.

The listed BCVA assessment is preoperative and at baseline. The registry gives no numerical mean or standard deviation for it. It also does not report a postoperative BCVA estimate or a statistical comparison. The registry entries that the outcome is continuous and that a mean and standard deviation are the intended summary do not permit those values to be reconstructed.

How should LogMar and BCVA be understood?

As a general measurement concept, LogMar represents visual acuity on a logarithmic scale. Lower values generally indicate better acuity. BCVA assesses vision with corrective lenses; the registry says the test uses lens correction with Snellen Charts. A scale’s direction and units matter when interpreting an estimate, but no estimate is reported in the registry record. The description of the measure should not be mistaken for an observed result.

What can a confidence interval or p-value add?

In general, a confidence interval communicates uncertainty around an estimated quantity under the statistical model and sampling assumptions. A narrow interval indicates greater precision than a wider interval for the same type of estimate, though precision does not establish that the estimate is unbiased or clinically important. A p-value addresses compatibility of the data with a specified null model; it is not the probability that a treatment works, nor does it measure the size or importance of an effect.

No confidence interval, p-value, or effect estimate for the primary outcome is reported in the registry record. The registry records 0 analyses. It is not possible to assess statistical significance, precision, or the stability of an estimate from the listed design details alone.

What do the planning assumptions mean?

The registry’s sample-size assumptions describe a planning illustration based on the observed effect, rather than the study’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The record also distinguishes how planning quantities are expressed: time-to-event calculations refer to total events, while other calculations refer to participants per arm.

These assumptions describe an illustration for planning a hypothetical comparison, not observed power for this single-group study. The registered study has no listed two-arm comparison, and the actual trial’s sample-size justification is not reported in the registry record. No numerical planning values or observed effect estimates are included in the registry record for interpretation. In general, sample-size illustrations depend on assumptions about the effect, variability, allocation, and analysis; they do not demonstrate that a completed study had a particular probability of detecting an effect.

Why do analysis choices matter?

General statistical practice requires specifying which participants contribute to each endpoint, how missing observations are handled, and what model or test will be used. For repeated measurements, the method should account for the way observations from the same participant are related. For multiple outcomes or repeated tests, a plan may also address the chance of false-positive findings across analyses. These are general considerations, not methods identified for this study.

The registry does not report the statistical analysis plan, missing-data methods, or analysis populations. It lists 7 outcome measures and 0 analyses. As a result, the method used to estimate outcomes, handle incomplete observations, or address multiplicity cannot be evaluated from the registry record.

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("Omidria")
n   <- c(94)
m   <- c(0.28)
sp  <- c(0.2)
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  Omidria  94  0.280  0.200  0.239  0.321

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 7 outcome measures and 0 analyses. It identifies preoperative BCVA as the primary measure, but the record does not report numerical results or explain how the other outcomes relate to the primary question. Statistical analysis methods, prespecified outcome hierarchy, and any approach to multiplicity are not reported in the registry record.

In general, testing several outcomes or several contrasts can increase the chance of finding at least one apparently unusual result even when there is no true effect. A prespecified hierarchy, adjustment, or other strategy can help interpret results across multiple tests. Whether such a strategy was used for this study is not reported, and no results are available to evaluate how multiplicity might affect interpretation.

Missing-data procedures and analysis populations are also not reported in the registry record. The enrollment entry is 94, but the record does not state how many participants contributed data to each measure, whether outcome data were incomplete, or how any missing observations were handled. It does not describe an intention-to-treat, per-protocol, or other analysis population. These omissions matter because outcome estimates depend on which observations are included and how missingness is addressed.

The registry’s planning assumptions concern an illustration based on an observed effect and a hypothetical two-arm comparison. They do not constitute the analysis plan for this single-group study, and the record does not provide the trial’s own sample-size justification. Consequently, the record does not support an assessment of planned statistical power, multiplicity control, or the consequences of missing data.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: blindness (1.1%).

The registry records 94 participants at risk for serious adverse events and 1 affected by a serious adverse event in the Omidria group. It lists 0 deaths. The serious-event term shown is Blindness, with a reported value of 1.1%. The record does not describe the event’s timing, clinical circumstances, relationship to the intervention, or outcome.

The record also lists 94 participants at risk for other adverse events and 94 affected. These entries are counts as recorded; they do not specify the nature, severity, duration, or number of separate events. They should not be treated as evidence that every event was caused by the intervention. A registry adverse-event listing is a safety report, not a causal analysis.

In general, “at risk” identifies the group used for the reported safety count, while “affected” records participants meeting the reported event category. Interpretation depends on the category definitions, collection methods, follow-up, and attribution rules. Those details are not reported in the registry record. The serious adverse event and the listed serious-event term should therefore be read as reported safety information, not as proof of causation or as a complete account of comparative safety. No control group is listed for a comparative safety assessment.

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

The registry record establishes that a completed, single-group study evaluated intraoperative phenylephrine/ketorolac infusion in cataract surgery. The intervention description specifies Omidria at 1%/0.3%, administered to all enrolled participants. The record identifies cataract as the condition and gives enrollment as 94. It also lists preoperative BCVA as the primary outcome, measured at baseline in LogMar.

Those details do not establish the effect of the infusion. No numerical result for the primary measure, postoperative BCVA result, or result for retinal thickness or macular edema is reported in the registry record. Without an outcome estimate and its uncertainty, the magnitude and precision of any change cannot be assessed. Completion status and enrollment are not substitutes for outcome data.

The single-group design also does not provide a concurrent control for distinguishing intervention-associated change from other changes over time. The study summary refers to topical NSAID drops as the alternative approach, but the record lists no such comparison arm. It therefore does not support a direct efficacy or safety comparison between infusion and topical drops.

In general, a treatment effect is a comparison between outcomes under different treatment conditions, interpreted in light of study design and uncertainty. A baseline measure describes starting status, not what happened after treatment. Even if a within-group follow-up change were reported, it would not by itself establish what would have happened to the same population without the intervention. This is why design, outcome timing, analysis, and uncertainty all matter.

The record does report adverse-event entries, including a serious adverse event and a serious-event term. Those entries describe what was registered, but they do not establish that the intervention caused the event, and no comparator is available for a comparative safety judgment. The cautious conclusion is that the registry identifies the study’s intervention, design, and intended questions but does not report the results needed to determine treatment effects.

14. Why This Trial Matters Statistically

This study illustrates a basic alignment question in clinical research: does the outcome listed as primary directly answer the question emphasized by the study title? The title concerns retinal thickness and macular edema, whereas the listed primary measure is preoperative BCVA at baseline. A clear distinction between the stated topic and the registered primary measure is essential because the endpoint determines what a study can directly quantify.

It also illustrates why a treatment description is not the same as a comparative design. The summary frames infusion as an alternative to topical NSAID drops around surgery, yet the record lists a single group receiving the infusion and no topical-drop control. Readers should distinguish the clinical rationale from the comparison actually recorded. Without a concurrent comparator, changes among treated participants cannot isolate the intervention’s contribution.

The record further shows why completion and enrollment should not be confused with a report of results. Although the registry marks the study completed and lists enrollment of 94, it provides no analyses and no numerical primary outcome result. A study can have a defined intervention and a completed status while leaving the key effect estimate and its uncertainty unavailable in the record.

Finally, the contrast between the study design and the stated planning illustration is instructive. The planning assumptions refer to a hypothetical two-arm comparison, while the registered study is single group. Planning illustrations can help explore future study requirements, but they are not evidence of observed power or a substitute for a prespecified analysis of the completed study. Taken together, these features make the record useful for understanding what was intended and how it was registered, while also showing why design, endpoint alignment, and complete reporting are central to 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 registry’s primary outcome is preoperative BCVA at baseline, while the title emphasizes retinal thickness and macular edema. The registry record does not report numerical results for the listed primary measure or results for the retinal outcomes named in the title. This limits the ability to assess whether the recorded outcomes address the stated clinical focus.

The study is single group, with no concurrent control listed. The summary describes the infusion as an alternative to topical NSAID drops before and after surgery, but the record does not list a topical-drop comparison arm. This prevents a direct comparative interpretation from the registered design. Allocation is recorded as NA and masking as none; further details about assignment or outcome assessment are not reported in the registry record.

The record lists 7 outcome measures and 0 analyses. It does not describe the statistical analysis plan, outcome-specific denominators, analysis populations, missing-data handling, or multiplicity strategy. It also does not report the trial’s sample-size justification. The planning assumptions describe an illustration for a hypothetical two-arm comparison, not the actual single-group study’s analysis.

Safety entries are limited in their interpretability because event definitions, timing, follow-up, and attribution are not reported. The listed serious event and other adverse-event counts therefore cannot establish causation or provide a controlled safety comparison. More broadly, the registry record does not include the outcome estimates and uncertainty needed to assess effect size or precision. These limitations concern the information available in the registry record and do not establish what may or may not have been collected outside it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: No Drop Post-Op Cataract Surgery — NCT03864133.
• Registry record last updated 2023-11-30; status last verified 2021-06.
• Results first posted 2023-11-30.
• 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

NCT03864133 is a completed Phase 4, single-group study sponsored by Wake Forest University Health Sciences. The record lists enrollment of 94, with a start date of 2019-07-08 and primary completion date of 2021-06-30. Participants were to receive Omidria, described as phenylephrine/ketorolac at 1%/0.3%, during cataract surgery.

The study title concerns retinal thickness and macular edema. Its listed primary measure is preoperative BCVA at baseline, summarized as a mean with standard deviation in LogMar. The registry lists 7 outcome measures and 0 analyses. Numerical results for the primary endpoint and postoperative retinal outcomes are not reported in the registry record. No concurrent comparator is listed, and the record does not report analysis populations, missing-data methods, or a statistical analysis plan.

Safety entries include 1 serious adverse event, a serious-event term of Blindness at 1.1%, and 0 deaths; causal attribution is not reported.