Comment on: “Angle Kappa is Not Correlated with Patient-Reported Outcomes After Multifocal Lens Implantation” [Letter]
Bibliographic record
Abstract
We read "Angle Kappa is Not Correlated with Patient-Reported Outcomes After Multifocal Lens Implantation" by Liu et al, which analyzes the impact of angle kappa on patient-reported outcomes after multifocal intraocular lens (MIOL) implantation. 1e noted the omission of a critical source reference that significantly contributes to the understanding of this debate and topic.In the Journal of Refractive Surgery Dec. 2023, we published "Angle Kappa Influence on Multifocal IOL Outcomes".This study examines MIOL patient-reported outcomes in relation to preoperative angle kappa in a cohort of 26,470 eyes. 2 We appreciate the authors for reproducing and validating our findings by utilizing the Pentacam "chord length" instead of the Orbscan kappa displacement distance to measure angle kappa.Their study, mirroring our conclusions, confirms that angle kappa lacks significant correlation with patient-reported outcomes and cannot be used as a criterion for MIOL candidacy.We demonstrated that preoperative angle kappa did not have a predictive clinical impact on postoperative MIOL visual outcomes, refractive accuracy, subjective patient satisfaction at near, intermediate and far distance, nor with the likelihood of recommending an MIOL procedure to friends and relatives. 2Our study also noted a larger angle kappa in right vs. left eyes.Liu et al add validity to our existing findings 2 and confirms, along with several previous studies, 3-9 that angle kappa as a single variable cannot be used to determine MIOL candidacy.The novelty of the study by Liu et al lies in reaching the same conclusion with angle kappa measurements taken by Pentacam and adding photic phenomena data.The authors state "as angle kappa and chord length are used interchangeably in the refractive literature, the chord length is referred to as angle kappa in this manuscript". 1While the Pentacam chord length is a good proxy for angle kappa, this chord, and other measures of angle kappa in mm are not interchangeable, even though those terms are often wrongfully substituted.For example, the Pentacam angle kappa chord length of 0.41 mm in Liu's study is significantly shorter than the Orbscan kappa displacement distance of 0.63 mm in our study.In summary, Liu et al reproduced our large cohort study's conclusions and they bring further evidence that angle kappa, as an independent variable, cannot be used as a selection criterion for MIOL candidacy.Further discussion of key previous studies on this topic would have enhanced the depth of their analysis and improve readers' comprehension of the growing body of evidence concluding that angle kappa does not significantly impact postoperative MIOL outcomes.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".