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 Single Center Exploratory Study To Evaluate The Use Of The RxSight Light Adjustable Lens (LAL) And The Light Delivery Device (LDD) To Improve Visual Outcomes (NCT04529616), a na phase not stated study. The primary outcome is Percent of Eyes With Uncorrected Distance Visual Acuity (UCDVA) of 20/20 or Better.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04529616 |
| Phase | Phase not stated |
| Condition | Aphakia, Cataract |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 79 |
| Arms in the primary outcome | n/a |
| Lead sponsor | RxSight, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns visual correction of aphakia and lists aphakia and cataract as conditions. The registry record does not report further eligibility details or a fuller description of the participants.
Intervention
The device intervention was the RxSight Light Adjustable Lens (LAL) and Light Delivery Device (LDD). The study objective was to evaluate whether visual outcomes could be improved after adjustments of the LAL using the LDD.
Comparator
The registry describes a single-group study and does not report a separate comparator group. The record therefore does not describe a randomized comparison with another treatment or a control condition.
Primary question
The listed primary outcome measure is the count of eyes with uncorrected distance visual acuity (UCDVA) of 20/20 or better at 3 months post op. The study summary says that no primary effectiveness endpoints will be identified, so the listed measure should not be treated as a declared primary effectiveness endpoint.
In statistical terms, the record describes an exploratory evaluation of a device combination in a single group, with visual acuity as a recorded outcome measure. It does not establish a comparative question about whether the device combination produces better outcomes than another intervention. Nor does the record state a prespecified threshold for what would count as an important improvement. The reported objective is to examine visual outcomes after lens adjustments; the available registry information does not establish whether an observed outcome would be attributable to the device, to the adjustment procedure, or to other factors.
3. Trial Design
The registry describes NCT04529616 as a completed, single-center exploratory study of the RxSight Light Adjustable Lens and Light Delivery Device. The study began on 2020-05-22, and the primary completion date is 2022-10-01. The recorded enrollment is 79. The intervention is classified as a device, and the study model is single group. Allocation is recorded as NA, and masking is recorded as none.
A single-group design describes outcomes in one group receiving the intervention; it does not by itself provide a concurrent control for comparison. In this record, no separate comparator arm is described. As a result, the design can describe the recorded outcomes in the study group, but cannot directly estimate how those outcomes would compare with outcomes under another intervention or under a control condition. The record does not report a before-and-after comparison plan, so one should not infer that such an analysis was conducted.
The study summary calls the investigation exploratory and says that no primary effectiveness endpoints will be identified. The registry nevertheless lists an outcome measure for the percentage of eyes with UCDVA of 20/20 or better at 3 months post op. These statements convey different things: an outcome measure is listed, but the summary does not designate a primary effectiveness endpoint. No analysis results are listed in the record, and the statistical analysis plan is not reported in the registry record.
Enrollment describes the recorded study size, not the number of eyes with an available measurement for every outcome. The outcome population and any exclusions from analysis are not reported in the registry record. The single-center setting and exploratory design also mean that the record does not establish how well results would generalize to other settings or populations.
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
| Stage | Light Adjustable Lens (LAL) and Light Delivery Device (LDD) |
|---|---|
| STARTED | 79 |
| COMPLETED | 79 |
| NOT COMPLETED | 0 |
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 | Light Adjustable Lens (LAL) and Light Delivery Device (LDD) |
|---|---|---|
| Participants analysed | 79 | |
| Age, Continuous | years | 66.6 (SD 7.2) |
| Sex: Female, Male: Female | Participants | 53 |
| Sex: Female, Male: Male | Participants | 26 |
| Race/Ethnicity, Customized: White | Participants | 59 |
| Race/Ethnicity, Customized: Black | Participants | 0 |
| Race/Ethnicity, Customized: Other | Participants | 0 |
| Race/Ethnicity, Customized: Not Reported | Participants | 20 |
| Region of Enrollment: Mexico | participants | 79 |
6. Primary Endpoint
The registry lists the primary outcome as Percent of Eyes With Uncorrected Distance Visual Acuity (UCDVA) of 20/20 or Better, measured over 3 months post op.
| Element | Registry entry |
|---|---|
| Result type | Count Of Units |
| Measure of spread | not applicable |
| Unit | Eyes |
| Endpoint classification | not reduced to a single comparison |
The listed outcome measure is the count of eyes with uncorrected distance visual acuity (UCDVA) of 20/20 or better at 3 months post op. UCDVA assesses distance vision without refractive correction. The threshold classifies an eye according to whether its measured acuity reaches 20/20 or better; the measure is therefore a count of eyes meeting a stated visual-acuity criterion, rather than a continuous summary of acuity across all eyes.
The registry says values were measured using Early Treatment Diabetic Retinopathy Study (ETDRS) testing. A defined test and threshold can make an outcome easier to interpret by specifying how the measurement is obtained and what qualifies for the count. A fixed follow-up time also indicates when the outcome is intended to be assessed. These features describe the measure, but do not indicate how many eyes met the threshold or how complete the measurements were.
The record lists the outcome under primary measures, while the study summary explicitly says that no primary effectiveness endpoints will be identified. That distinction matters: the listed measure can be described as a registry outcome measure without calling it a prespecified primary effectiveness endpoint. The actual count, denominator, and any estimate of uncertainty are not reported in the registry record. The record also does not report whether the analysis unit was chosen to account for any relationship between eyes from the same participant.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an exploratory, single-group device study with recorded enrollment of 79. It lists a visual-acuity outcome defined as the count of eyes with UCDVA of 20/20 or better at 3 months post op. However, the result for this outcome is not reported in the registry record. There is therefore no posted estimate in the registry record from which to describe the observed visual-acuity distribution, its precision, or the proportion of eyes meeting the threshold.
The study summary says that no primary effectiveness endpoints will be identified. Although a primary outcome measure is listed, that measure should not be treated as a declared primary effectiveness endpoint in the face of that statement. The record also lists no analyses. It does not report an effect estimate, confidence interval, p-value, or model-based result for the visual-acuity measure. Without those results, the registry information does not support a statistical conclusion about the direction or magnitude of an outcome.
The single-group design limits what a reader could conclude even if a within-group outcome were posted. An outcome observed in the group would describe that group at the stated assessment, but, without a comparator, it would not directly quantify a difference from another treatment or a control. A single-group observation also cannot by itself separate the effects of the lens, delivery device, adjustments, and other influences on visual acuity.
General statistical context: an estimate describes the value calculated from observed data, while a confidence interval describes the uncertainty around that estimate under the assumptions of the analysis. A narrow interval generally indicates greater precision than a wide interval, but precision does not resolve limitations in the design or establish causation. No estimate or interval for the visual-acuity outcome is reported in the registry record, so those aspects of the result cannot be assessed from the record.
The safety information is also descriptive. The listed intervention group has 2 participants at risk for serious adverse events and 2 affected, and 9 at risk for other adverse events with 9 affected; deaths are recorded as 1. These counts do not establish whether events were caused by the device or procedure. The registry record does not report the relevant analysis details or a comparison group that would support a comparative safety estimate.
Any planning calculations based on an observed effect should be read as hypothetical illustrations, not as the trial's observed power or a justification for the original enrollment. The record describes such calculations as using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions do not change the fact that this study is recorded as single group and has no reported analyses.
9. Statistical Methods Explained
The record identifies a single-group study with no masking and allocation recorded as NA. It also lists no analyses. Consequently, there is no reported statistical test, model, adjustment strategy, or inferential result to explain as an analysis actually conducted in this study. The discussion below is general statistical context and should not be read as a description of methods used by the investigators.
What does a single-group design estimate?
In general, a single-group study can describe outcomes among the people or eyes observed after an intervention. A descriptive count gives the number meeting a criterion, while a proportion relates that count to the number with usable measurements. Neither description creates a comparison group. Without a concurrent comparator, a difference between the observed outcome and an external expectation is not automatically an estimate of the intervention's effect; that interpretation would depend on assumptions and design features not reported in the registry record.
For this study, the listed measure is a count of eyes meeting the UCDVA threshold at 3 months post op. The outcome population and denominator are not reported in the registry record. Although enrollment is recorded as 79, enrollment alone does not establish how many eyes had outcome data or which eyes entered an analysis. The registry also does not report whether both eyes could contribute data for a participant or how any correlation between eyes would be handled.
Why does the unit of analysis matter?
General statistical context: measurements from two eyes of one participant may be related because they belong to the same person. If the analysis treats related measurements as fully independent, uncertainty can be understated. Methods that account for clustering or within-person correlation can be appropriate when the design and data structure call for them. The registry record does not describe the eye-level data structure or an approach to this issue, so it is not possible to determine whether or how it was addressed.
What do confidence intervals and p-values convey?
General statistical context: a confidence interval expresses the precision of an estimate under the chosen method and its assumptions. It is not a guarantee that the estimate is free of bias, and it does not address the absence of a comparator. A p-value summarizes how compatible data are with a specified statistical model or null hypothesis; it is not a measure of clinical importance and does not establish causality. Neither a confidence interval nor a p-value for the listed visual-acuity measure is reported in the registry record.
How should planning calculations be read?
General statistical context: sample-size calculations estimate the amount of information a future study might need under stated assumptions about the target effect, variability, significance level, power, allocation, and analysis. The registry's stated planning illustration is based on the observed effect and is not described as the trial'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 described as a fraction of the observed effect.
Such an illustration is a planning exercise, not observed power. Observed power is not a substitute for reporting an estimate and its uncertainty, and a calculation based on an observed effect can be sensitive to that effect's uncertainty. The record's study model is single group, whereas the planning assumptions describe equal allocation between two arms. That difference means the planning exercise should not be mistaken for the design that was conducted. No numerical planning results are reported in the registry record of the registry record.
Why can over-dispersion matter?
General statistical context: count outcomes are sometimes analyzed with models that assume a particular relationship between the average count and its variability. Over-dispersion occurs when observed variability is greater than that assumption allows. If it is ignored, standard errors and confidence intervals may be too small, and tests can appear more conclusive than the data warrant. Whether this issue is relevant depends on the outcome structure and analysis. The record does not report a count model or enough outcome detail to assess over-dispersion for this study.
Overall, the registry record supports describing the design, the listed outcome definition, and the available safety counts. It does not provide the analysis methods or visual-acuity results needed for an inferential interpretation. Statistical methods are general explanations, not claims about methods used in this trial.
10. Multiplicity, Missing Data and Analysis Populations
The study summary states that no primary effectiveness endpoints will be identified, while the registry lists a primary outcome measure for eyes with UCDVA of 20/20 or better at 3 months post op. This leaves an important distinction between a listed measure and a declared primary effectiveness endpoint. The record does not report a hierarchy of outcomes or a plan specifying which result would be considered confirmatory.
Multiplicity arises when multiple outcomes, time points, subgroups, or analyses are examined. In general, making many statistical comparisons can increase the chance of finding an apparently notable result by chance. Methods to manage this may include prespecifying a primary endpoint, adjusting inference, or treating results as exploratory. The registry record does not report a multiplicity strategy, and it lists no analyses, so it is not possible to determine whether any adjustment was used or needed in the investigators' analyses.
Missing-data details are also not reported in the registry record. The record does not describe the amount or reasons for missing visual-acuity measurements, how missing values were handled, or whether a sensitivity analysis was planned. These details matter because analyses based only on observed measurements can be affected if availability of an outcome is related to the outcome itself or to participant characteristics.
The analysis population is not reported in the registry record. Enrollment of 79 does not establish the denominator for the eye-based outcome, and no outcome result or analysis denominator is reported. The record also does not state whether all enrolled participants, all treated participants, or a different group would be included in each analysis. These omissions limit assessment of the outcome's completeness and the reproducibility of any analysis.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Light Adjustable Lens (LAL) and Light Delivery Device (LDD) | 2 | 79 | 2.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Light Adjustable Lens (LAL) and Light Delivery Device (LDD) | 1 of 79 |
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 |
|---|---|
| Light Adjustable Lens (LAL) and Light Delivery Device (LDD) | 9 of 79 |
Most frequent serious adverse event terms
| Event term | Organ system | Light Adjustable Lens (LAL) and Light Delivery Device (LDD) |
|---|---|---|
| Cardiogenic Shock | Cardiac disorders | 1 of 79 |
| Blood clots secondary to head trauma from a fall | Vascular disorders | 1 of 79 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Light Adjustable Lens (LAL) and Light Delivery Device (LDD) |
|---|---|---|
| Epiretinal membrane | Eye disorders | 3 of 79 |
| Drusen | Eye disorders | 2 of 79 |
| Intraretinal microhemorrhage secondary to diabetes and hypertension | Eye disorders | 1 of 79 |
| Microaneurism, intraretinal hemorrhage dots secondary to history of diabetes | Eye disorders | 1 of 79 |
| Corneal epithelium: epithelialized with SPK | Eye disorders | 1 of 79 |
| Granular deposits over IOL | Eye disorders | 1 of 79 |
| Pigmentary changes | Eye disorders | 1 of 79 |
| Optic nerve edema secondary to head trauma | Nervous system disorders | 1 of 79 |
| Posterior capsular opacity | Eye disorders | 1 of 79 |
Serious events with the highest arm-level rate: cardiogenic shock (1.3%), blood clots secondary to head trauma from a fall (1.3%).
The registry lists one intervention group, Light Adjustable Lens (LAL) and Light Delivery Device (LDD). For serious adverse events, 2 are recorded as affected among 79 at risk. For other adverse events, 9 are recorded as affected among 79 at risk. The death count is 1. These are separate registry entries; they should not be added together or interpreted as a count of distinct participants.
The serious adverse event terms listed are “Cardiogenic Shock” and “Blood clots secondary to head trauma from a fall,” each displayed with 1.3%. The registry record does not provide further details about the events, their timing, or whether investigators considered them related to the device or procedure. The recorded death count does not, on its own, establish cause or relationship to the intervention.
General statistical context: adverse-event counts describe what was recorded in a group. In the absence of a comparator, they do not provide a relative-risk estimate or show whether event occurrence differs from what would have happened under another condition. The record does not report a comparative safety analysis or additional methods for interpreting these entries.
12. What the Result Does, and Does Not, Mean
The registry record identifies an exploratory evaluation of the RxSight Light Adjustable Lens and Light Delivery Device for visual correction of aphakia. It lists UCDVA of 20/20 or better at 3 months post op as an outcome measure and specifies ETDRS testing. Those details tell readers what the measure concerns and when it was intended to be assessed. The record does not report the outcome result, so it cannot establish how many eyes met the criterion or how precisely any result was estimated.
The study summary says that no primary effectiveness endpoints will be identified. Thus, the listed visual-acuity measure should not be presented as a declared primary effectiveness endpoint. The record also lists no analyses. It does not report an estimate, confidence interval, p-value, or analysis population for visual acuity. This prevents interpretation of the magnitude, precision, or statistical evidence associated with that outcome.
The single-group design can describe observations in the intervention group, but it does not provide a direct comparison with another treatment or a control. Even a favorable observed outcome would not, by itself, establish that the device combination caused the outcome. The registry information does not separate the contribution of the lens, delivery device, adjustment procedure, or other factors.
The safety entries are likewise descriptive and do not establish causation. The record lists serious and other adverse-event counts and a death count, but does not report further event context or comparative analyses. These entries should be read as recorded events in the group, not as proof that an event was or was not caused by the intervention.
Overall, the record documents the study objective, design, outcome definition, and selected safety counts. It does not report the effectiveness results needed to characterize visual outcomes or make a comparative claim.
13. Why This Trial Matters Statistically
This trial is statistically notable for the distinction between an outcome measure listed in the registry and the study summary's statement that no primary effectiveness endpoints will be identified. A measure can be defined and recorded without serving as a prespecified primary endpoint. Keeping that distinction clear helps prevent exploratory outcome descriptions from being interpreted as confirmatory evidence.
The single-group design also illustrates the difference between describing outcomes and estimating comparative effects. A group-level result can be informative about what was observed in that setting, but a comparator is ordinarily needed to estimate how outcomes differ under an alternative condition. The registry describes no separate comparator group, so it does not support a direct treatment contrast.
The outcome is eye-based, while enrollment is recorded for the study. That makes the analysis unit and denominator important: enrollment does not itself establish the number of eyes assessed or how measurements from two eyes belonging to one participant were handled. Those analysis details are not reported in the registry record.
Finally, an endpoint definition and an exploratory objective do not replace reporting the observed estimate and its uncertainty. The registry identifies a threshold, assessment time, and measurement method, but does not report the visual-acuity outcome result or an analysis. The record therefore offers a useful example of why design, endpoint status, analysis methods, and results must be read separately when interpreting a clinical study.
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 registry record does not report the visual-acuity result, its denominator, or an estimate of uncertainty. It also lists no analyses. Accordingly, the outcome's magnitude, precision, and statistical treatment cannot be evaluated from the registry information.
The record describes a single-group study and does not report a separate comparator. This limits direct interpretation of outcomes as differences attributable to the intervention. The study summary characterizes the work as exploratory and says that no primary effectiveness endpoints will be identified, while a primary outcome measure is listed. The record does not explain this distinction further.
Important design and analysis details are not reported in the registry record, including eligibility criteria, the analysis population, the number of eyes with available measurements, handling of missing outcomes, and how potential dependence between eyes from one participant was addressed. The statistical analysis plan, multiplicity strategy, and any sensitivity analyses are also not reported. These gaps limit reproducibility and assessment of possible sources of bias.
The safety information is limited to recorded counts and listed serious-event terms. The record does not report event timing, investigator assessments of relatedness, or comparative safety analyses. The registry's planning-illustration assumptions do not describe the single-group design actually recorded, and the trial's original sample-size justification is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Single Center Exploratory Study To Evaluate The Use Of The RxSight Light Adjustable Lens (LAL) And The Light Delivery Device (LDD) To Improve Visual Outcomes — NCT04529616.
- Registry record last updated 2025-02-10; status last verified 2025-02.
- Results first posted 2025-02-10.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT04529616 is recorded as a completed, single-center exploratory device study of the RxSight Light Adjustable Lens and Light Delivery Device. Enrollment is 79. The study began on 2020-05-22, with primary completion on 2022-10-01. The record lists aphakia and cataract as conditions and describes a single-group design with allocation recorded as NA and no masking.
The listed outcome measure is the count of eyes with UCDVA of 20/20 or better at 3 months post op, measured using ETDRS testing. The study summary states that no primary effectiveness endpoints will be identified. The visual-acuity result and analysis methods are not reported in the registry record.
The safety record lists 2 affected among 79 at risk for serious adverse events, 9 affected among 79 at risk for other adverse events, and 1 death. The listed serious-event terms are Cardiogenic Shock and Blood clots secondary to head trauma from a fall, each displayed as 1.3%.