Clinical Study to Evaluate the Safety and Effectiveness of the RxSight Light Adjustable Lens (LAL) in Subjects With Prior Corneal Refractive Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Study to Evaluate the Safety and Effectiveness of the RxSight Light Adjustable Lens (LAL) in Subjects With Prior Corneal Refractive Surgery (NCT03660865), a randomized na study. The primary outcome is Magnitude of Manifest Cylinder (MRCYL) Compared Between the Two Study Groups, LAL and Control.

2. Clinical Question

This is an eye-level comparison in a study of people with prior corneal refractive surgery. The study description focuses on the safety and effectiveness of the LAL and LDD for visual correction of aphakia, with fellow eyes serving as the control. The key statistical question is whether the mean primary outcome differed between the two assigned eye groups at the specified follow-up.

The registry record calls the study randomized and controlled, and its official title describes it as prospective and multicenter. It also labels the design model as single group. Those recorded labels do not fully align with the described two-eye allocation and two intervention groups; the record does not explain the difference. The study was unmasked, so masking of participants or investigators is not reported as part of the design.

3. Trial Design

The registry record describes a prospective, randomized, controlled, multicenter clinical study of the RxSight LAL and LDD in participants with prior corneal refractive surgery. Its status is completed. The recorded start date is 2018-08-28, and the primary completion date is 2020-04-01. The phase is listed as NA, and the recorded enrollment is 105.

The described allocation is within participants’ eyes: a predetermined randomization scheme designated a primary eye to receive the LAL and a fellow eye to receive the control IOL. Both interventions are classified as devices. The LAL arm description identifies the primary eye as the LAL eye; the control arm description identifies the fellow eye as the control eye. This supports reading the comparison as involving eyes from the same participants, but the posted comparison does not state whether its statistical analysis accounted for within-participant pairing or correlation between eyes.

The registry lists masking as none. It records a single-group model even though it also describes randomized assignment between LAL and control eyes and posts results for both groups. This internal design-label tension is not explained in the registry record and should be kept in mind when interpreting the study structure.

The primary outcome is a continuous measure: mean MRCYL in diopters at Postop Month 6, with standard deviations reported for both groups. The record lists five outcome measures, including the primary measure and two secondary UCDVA outcomes. It does not report the trial’s original sample-size justification, detailed analysis plan, handling of paired observations, or analysis populations. The sponsor is RxSight, Inc.

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 Magnitude of Manifest Cylinder (MRCYL) Compared Between the Two Study Groups, LAL and Control, measured over Postop Month 6.

The primary endpoint is the mean magnitude of manifest cylinder (MRCYL), measured in diopters at Postop Month 6. Manifest cylinder is a refractive measure that describes the cylindrical component of refractive error measured through manifest refraction. In general, a group mean describes the average observed measurement, while the standard deviation describes how dispersed individual measurements are around that average.

The endpoint is relevant to the stated study objective because the registry describes evaluation of postoperative refractive error after prior corneal refractive surgery. A comparison of group means can indicate whether the average recorded cylinder measurement differed between the LAL and control eyes at the specified follow-up. It does not, by itself, describe how many individual eyes had a particular measurement or how outcomes were distributed across participants.

The posted means are -0.319 for the LAL group and -0.452 for the control group. The reported mean difference, expressed as LAL minus control, is 0.133. Because the recorded values are negative, that positive difference means the LAL group mean was less negative; it should not be translated into a claim about clinical importance without an established threshold or further clinical context. Such a threshold is not reported in the registry record.

Although the endpoint title uses the word magnitude, the posted group summaries are signed values. The registry record does not provide additional detail about how the endpoint was derived or whether any transformation or sign convention was applied. The result therefore supports a comparison of the posted means, not a broader claim about individual refractive outcomes.

7. Results Posted in the Registry

• Light Adjustable Lens (LAL) and Light Delivery Device (LDD): mean -0.32 versus -0.45 on control; difference 0.13 (95% CI 0.03 to 0.24), standardized effect d = 0.34; z-test p = 0.014.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Uncorrected Distance Visual Acuity (UCDVA)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Light Adjustable Lens (LAL) and Light Delivery Device (LDD): mean 0.00 versus 0.05 on control; difference -0.05 (95% CI -0.08 to -0.02), standardized effect d = -0.42; z-test p = 0.002.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Light Adjustable Lens (LAL) and Light Delivery Device (LDD) than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Uncorrected Distance Visual Acuity (UCDVA) for Subjects Measured With Keratometric Cylinder (Kcyl) <0.75 D in Both Eyes at the Preoperative Examination

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Light Adjustable Lens (LAL) and Light Delivery Device (LDD): mean -0.00 versus 0.06 on control; difference -0.06 (95% CI -0.12 to -0.01), standardized effect d = -0.51; z-test p = 0.021.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Light Adjustable Lens (LAL) and Light Delivery Device (LDD) than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes both concern uncorrected distance visual acuity at Postop Month 6, measured on the logMAR scale. Across the overall comparison and the restricted preoperative keratometric-cylinder subset, the posted LAL-minus-control differences are negative. That common numerical direction means the LAL group means are lower on the recorded scale in both comparisons. These are related findings, but their outcomes and analysis populations differ from the primary MRCYL comparison.

The primary result concerns mean manifest cylinder, while the secondary outcomes concern UCDVA. A similar statistical direction across outcomes can provide context, but measurements on different scales are not directly interchangeable. The secondary comparisons do not independently validate the primary endpoint, and the restricted subset addresses only participants meeting the recorded preoperative criterion.

Each secondary comparison has an unadjusted p-value and interval. The registry record does not report a multiplicity adjustment or a hierarchy specifying how secondary results should be interpreted. When multiple outcomes are tested, treating each unadjusted result as confirmatory can overstate the strength of evidence. The findings are therefore useful as supporting descriptive information, but should carry less inferential weight than a prespecified primary analysis with a documented testing strategy.

The record lists no reported analyses for the secondary outcomes. It does not say whether the subset analysis was prespecified, whether exclusions were applied, or whether the same statistical assumptions were used across the two comparisons. Those omissions make it difficult to distinguish planned secondary questions from exploratory analyses. The overall pattern can be noted without treating the secondary findings as proof of a broader or consistent effect.

Because the secondary results are not adjusted for multiplicity and their analysis details are unreported, their role is contextual: they show how the posted acuity summaries compare, while leaving substantial questions about analysis planning and interpretation unanswered.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Uncorrected Distance Visual Acuity (UCDVA)
• Uncorrected Distance Visual Acuity (UCDVA) for Subjects Measured With Keratometric Cylinder (Kcyl) <0.75 D in Both Eyes at the Preoperative Examination

9. Statistical Interpretation

10. Statistical Methods Explained

The posted outcomes are continuous measurements, and the registry identifies the primary parameter as a mean with standard deviation. A mean is the arithmetic average of the measurements in a group. A standard deviation describes the spread of observations around that group mean; it is not the uncertainty of the mean itself. In general, individual observations can vary considerably even when a group mean is estimated with reasonable precision.

What does the mean difference represent?

The primary mean difference is calculated as the LAL group mean minus the control group mean. The posted means are -0.319 and -0.452, respectively, and the resulting difference is 0.133. A difference of zero would mean equal group means on the recorded scale. A positive difference means the LAL mean is higher numerically than the control mean; given the negative means, it is less negative. That numerical direction does not by itself determine clinical importance.

The mean difference is an unadjusted recalculation from the posted summary statistics. It summarizes the observed separation between the group means without accounting for other variables or design features unless those are incorporated into the calculation. No adjusted primary estimate or detailed sponsor analysis is reported in the registry record. The calculation should not be mistaken for an analysis that accounts for the fact that the comparison is described as involving primary and fellow eyes from the same participants.

What does a confidence interval tell us?

In general, a confidence interval expresses the uncertainty around an estimated quantity under a statistical model and its assumptions. For a difference in means, an interval that includes zero is compatible with equal means at the interval’s associated confidence level; an interval that excludes zero indicates that zero is outside the range of estimates supported by that calculation at that level. The primary interval reported for the recalculated difference is 0.027 to 0.239 and excludes zero.

An interval does not show the range of individual eye outcomes, nor does it guarantee that the true value lies within its endpoints. Its width depends on the observed variability, the amount of information, and the calculation’s assumptions. The posted result does not state whether the interval calculation accounts for within-participant correlation. Because each participant’s primary and fellow eyes are assigned to the two groups, that omission is relevant to how precisely the comparison should be interpreted.

How should the p-value be read?

In general, a p-value describes how compatible the observed data, or more extreme data, are with a specified null model. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical value of a difference. The primary unadjusted recalculation reports p = 0.014. That value accompanies the estimated difference and interval; it does not address potential bias, missing data, multiplicity, or whether the assumptions used in the calculation match the study design.

The secondary p-values are also unadjusted. When multiple outcomes or comparisons are examined, the chance of finding at least one apparently unusual result can increase. General statistical practice may address this through a prespecified multiplicity strategy, but such a strategy is not reported in the registry record. As a result, secondary p-values should be interpreted cautiously and in the context of the full set of outcomes.

Why does the eye-level allocation matter?

General statistical methods often assume that observations being compared are independent. Measurements from two eyes of the same participant may be correlated because the eyes share participant-level characteristics. If outcomes are paired or otherwise correlated, an analysis that treats them as independent can estimate uncertainty differently from an analysis that models the relationship between eyes. The registry describes assignment of the primary and fellow eyes but does not report whether the posted comparisons used a paired method, an independent-groups method, or another approach.

The group summaries list 105.0 observations in each group for the primary endpoint. Those counts alone do not reveal how the comparison handled the relationship between eyes. The record also gives no information about exclusions, missing observations, or whether all randomized eyes contributed to the endpoint. These details affect how the summaries relate to the original allocation.

What do the secondary outcomes add?

The secondary measures use mean UCDVA on the logMAR scale at Postop Month 6. The comparison for all measured subjects and the comparison restricted to subjects with keratometric cylinder below 0.75 D in both eyes at the preoperative examination are distinct estimands because the latter applies to a selected subset. The posted subgroup has 42.0 observations in each group. The registry does not report whether that subset was prespecified or how its analysis was planned.

In general, a subgroup result may differ from an overall result because it concerns a narrower population, has less information, or reflects chance variation. A subgroup comparison does not establish that effects differ between subgroups unless an interaction or direct between-subgroup comparison is reported. No such analysis is reported in the registry record. The secondary outcomes are therefore best read as additional descriptive comparisons rather than proof of a distinct subgroup pattern.

Finally, the record’s absence of reported analyses means that details such as covariate adjustment, missing-data handling, protocol deviations, and analysis population cannot be evaluated. The statistical summaries permit a basic comparison of posted means, but not a full audit of the trial’s analytic conduct.

11. Confidence Intervals and Precision

The primary difference in mean MRCYL is 0.133 for LAL minus control, with an interval from 0.027 to 0.239. The interval excludes zero and is entirely positive. This indicates that the recalculated difference is estimated with enough precision to distinguish it from zero under the calculation’s assumptions, while still leaving uncertainty about the exact size of the group-mean separation.

Precision concerns uncertainty in an estimated group difference, not the spread of individual outcomes. The primary standard deviations are 0.319 for LAL and 0.456 for control. These describe variation among recorded observations; the interval describes uncertainty around the mean difference. They answer different questions. Neither alone shows the range of outcomes experienced by individual participants.

The interval’s interpretation depends on the statistical model used to construct it. The registry does not report whether the calculation accounted for paired eyes or other features of the design, so the interval should be treated as an unadjusted recalculation from the posted summaries. The record does not state a clinically important difference threshold, meaning the interval cannot establish whether the estimated range is clinically meaningful.

The secondary UCDVA intervals are also reported as unadjusted comparisons. Both exclude zero, but their precision pertains to their own outcomes and populations; the restricted subset has fewer observations than the full posted comparison. These intervals do not correct for examining multiple outcomes, and their individual precision does not remove the uncertainty associated with an unreported analysis plan.

Overall, the primary estimate has a direction and interval that can be described statistically, but precise interpretation is limited by the unreported analysis details and clinical threshold. The intervals quantify only part of the uncertainty surrounding the results.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size display gives planning illustrations, not the trial’s original design calculation. For continuous outcomes, its values are participants per arm. The assumptions listed are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set to the stated fraction of the observed effect. The trial’s own original sample-size assumptions and justification are not reported in the registry record.

Rows describe planning for 100%, 75%, or 50% of the observed effect. Within each row, the 80% power column gives the participants per arm for 80% power under those assumptions; the 90% column gives the participants per arm for 90% power. In general, power is the probability that a study designed under the stated assumptions will detect an effect of the specified size using the stated testing approach, if that effect is present. Higher planned power generally requires more participants.

The displayed values are hypothetical planning quantities derived from the observed effect, rather than evidence that the completed study had a particular probability of detecting its result. They are not observed power. A smaller effect is harder to distinguish from random variation at a given level of precision, so planning for a smaller fraction of the observed effect requires more participants per arm. The figures should be understood as illustrations conditional on the stated assumptions, not as a reconstruction of the actual trial design.

The sample-size curve should be read in the same way as the rows: it represents hypothetical participant requirements as the effect being targeted changes. The primary and secondary outcomes have different observed effects and variability, so their planning figures differ. The record does not report whether the original study was planned using these outcomes, assumptions, or calculations.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 0.133; pooled standard deviation σ = 0.394.
2. n = 2 × (1.96 + 0.842)² × 0.394² / 0.133² = 137.4, rounded up to 138 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 0.133                      # observed difference in means
sigma <- 0.393507941470055                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(3660865)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 138 (80% power), 184 (90% power)
 75% of observed effect: n per arm = 245 (80% power), 328 (90% power)
 50% of observed effect: n per arm = 550 (80% power), 736 (90% power)
power.t.test: 138.4 
Simulated power at n = 138 per arm: 0.799 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary endpoint and secondary outcomes, but it does not report a multiplicity plan. Multiplicity arises when several outcomes, comparisons, subgroups, or analysis choices are examined. In general, repeated testing can increase the chance that at least one result appears statistically notable by chance. A prespecified strategy can define which result is primary and how other results will be treated, but such details are not reported.

The primary comparison is an unadjusted recalculation from the posted group summaries. The secondary comparisons are also unadjusted, and the registry record lists no reported analyses for them. The available information therefore does not establish whether the investigators used a hierarchy of outcomes, adjusted inferential thresholds, or considered the secondary analyses exploratory. Their p-values should not be interpreted as multiplicity-adjusted evidence.

Missing-data handling is not reported in the registry record. The posted group sizes indicate the observations summarized for each outcome, but the record does not explain whether all assigned eyes were measured, whether any observations were excluded, or why the endpoint counts may differ across outcomes. No imputation method, missingness assumption, or sensitivity analysis is reported. Without those details, it is not possible to assess how missing outcomes may have influenced the estimates.

The analysis population is also not reported. The registry does not specify whether results use all randomized participants or eyes, only those with available measurements, or another defined set. Nor does it report how protocol deviations were handled. These omissions matter because analysis populations can affect both the estimate and its uncertainty.

Finally, the registry describes randomized assignment of primary and fellow eyes but does not report the statistical method used to account for the within-participant relationship. It also labels the model as single group while describing two eye groups. No information resolves that discrepancy in design description. As a result, the posted summaries support descriptive comparisons, but a complete appraisal of multiplicity, missingness, and analysis populations is not possible.

15. 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: secondary surgical intervention (excluding posterior capsulotomy) (1.0%), clinically significant cystoid macular edema (0.0%).

The registry reports serious adverse events among 105 at risk in each group. The LAL and LDD group has 1 serious adverse event reported, while the control IOL group has 0. Deaths are recorded as 0 in both groups. The record lists secondary surgical intervention excluding posterior capsulotomy at 1.0% and clinically significant cystoid macular edema at 0.0% among the top serious-event terms.

Other adverse events are reported for 48 at risk in the LAL group and 38 at risk in the control group, with 105 at risk in each. These are posted counts, not evidence by themselves that the interventions caused the events. The registry record does not provide further detail on event definitions, severity breakdowns beyond the serious-event classification, timing, duration, or attribution.

Rare-event counts can be imprecise, and a zero count does not establish that an event cannot occur. The figures describe the events recorded in this study population and follow-up, not the full range of possible safety outcomes. They should be read alongside the limited detail in the registry record rather than as a comparative safety conclusion.

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

The posted primary outcome shows a difference in mean MRCYL at Postop Month 6 between the LAL and control eye groups. The LAL mean is -0.319 and the control mean is -0.452, with an unadjusted recalculated mean difference of 0.133. The associated interval excludes zero and the unadjusted p-value is 0.014. These figures describe the observed group summaries and the uncertainty from the recalculation.

They do not, on their own, establish that the difference is clinically important. The registry record does not report a threshold for a meaningful change in MRCYL, nor does it explain the endpoint’s sign convention beyond its title. Statistical evidence against equal means is not equivalent to evidence of a meaningful change for an individual eye or participant.

The two secondary UCDVA comparisons have negative LAL-minus-control mean differences, but they measure visual acuity rather than cylinder and include a restricted subset as well as the overall comparison. Their unadjusted nature and the absence of a reported multiplicity plan limit how strongly they can support a broad interpretation. The primary and secondary measures should be considered as distinct outcomes rather than combined into a single conclusion.

The study description and eye allocation make the comparison relevant to a randomized fellow-eye design, but the analysis method for within-participant correlation is not reported. The registry also does not report missing-data handling, analysis populations, or a detailed statistical plan. Thus, the posted comparisons cannot resolve whether uncertainty estimates fully reflect the design or whether all assigned eyes contributed.

The results are limited to the recorded measures and Postop Month 6. They do not establish longer-term outcomes, results for populations beyond those enrolled, or a causal explanation for the observed differences. Safety counts likewise describe the events recorded, without proving attribution or excluding uncommon events. The findings are best understood as registry-posted descriptive and recalculated statistical comparisons, with important clinical and methodological questions left open.

17. Why This Trial Matters Statistically

This trial illustrates a design in which the primary and fellow eyes of participants were assigned to different lens groups. Such a structure can make within-participant comparisons informative because the eyes share some participant characteristics. It also creates a statistical issue: measurements from the same person may be correlated. A sound analysis needs to reflect that relationship when estimating uncertainty, yet the registry record does not report how it was handled.

The record also illustrates why design labels and detailed methods matter. It describes randomized controlled allocation between LAL and control eyes, while the recorded model is single group. Without an explanation, readers cannot fully reconcile these labels. In addition, the record does not report the original sample-size justification, analysis populations, missing-data approach, or multiplicity strategy. These are not minor administrative details: they affect how confidently a reader can interpret estimates, intervals, and p-values.

Another statistical lesson is that a statistically distinguishable mean difference is not automatically clinically important. The primary comparison has an interval excluding zero, but the record supplies no clinical threshold for MRCYL. The secondary outcomes add perspective, yet unadjusted testing across outcomes and limited analysis details reduce their confirmatory weight.

Finally, the planning illustrations are derived from observed effects and stated hypothetical assumptions, not from the study’s original design plan. They can show how targeted effect size and planned power relate to participant requirements, but they do not retrospectively reveal the trial’s actual power. Taken together, the record is useful for examining the distinction between observed group summaries, uncertainty, statistical design, and clinical interpretation.

18. 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.

Several limitations are specific to the information recorded for this study. First, the design description is internally difficult to reconcile: the registry calls the study randomized and controlled and describes LAL and control eye groups, but also labels its model as single group. The record does not explain this inconsistency.

Second, the comparison is described as assigning each participant’s primary and fellow eyes to different groups, but the statistical analysis method is not reported. In general, two eyes from the same participant may have correlated measurements. Without a stated method, the reader cannot determine whether the posted uncertainty accounts for that feature.

Third, the registry does not report the original sample-size rationale, a complete statistical analysis plan, analysis populations, missing-data handling, or protocol-deviation procedures. It lists no reported analyses for the secondary outcomes. Multiplicity handling and whether the restricted UCDVA analysis was prespecified are also not reported. These gaps limit assessment of how the posted outcomes were selected and analyzed.

Fourth, the endpoint title refers to magnitude of manifest cylinder, while posted means are negative and no sign convention is explained. The record also provides no threshold for clinical importance. Consequently, the numerical difference can be described, but its clinical interpretation is less clear.

Finally, the primary and secondary outcomes are reported at Postop Month 6. Longer-term results are not included in the posted endpoint information. The record does not provide enough detail to assess the generalizability of the findings beyond the study population or the completeness of follow-up.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Clinical Study to Evaluate the Safety and Effectiveness of the RxSight Light Adjustable Lens (LAL) in Subjects With Prior Corneal Refractive Surgery — NCT03660865.
• Registry record last updated 2021-12-23; status last verified 2021-11.
• Results first posted 2021-11-22.
• 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.

22. Record Summary

NCT03660865 is a completed, randomized, controlled study of the RxSight Light Adjustable Lens and Light Delivery Device in subjects with prior corneal refractive surgery. The record describes random assignment of each participant’s primary eye to LAL and fellow eye to a control IOL, while also listing a single-group model and no masking. Enrollment is 105; the study start date is 2018-08-28 and primary completion date is 2020-04-01.

The primary outcome is mean MRCYL in diopters at Postop Month 6. The posted LAL and control means are -0.319 and -0.452, respectively; the unadjusted recalculated difference is 0.133, with p = 0.014. Secondary outcomes are UCDVA comparisons at the same follow-up. The registry record does not report the analysis plan, paired-eye handling, missing-data approach, analysis populations, multiplicity strategy, or original sample-size justification. Those omissions constrain interpretation of the posted statistical results.