Validity of Pachymetric Measurements by Manipulating the Acoustic Factor of Orbscan II
Bibliographic record
Abstract
PURPOSE: To assess the validity of pachymetric measurements by examining the constancy of the acoustic factor (AF) of the Orbscan II (Orbtek, Bausch & Lomb, Rochester, NY) after overnight rigid gas-permeable (RGP) contact lens wear. METHODS: Twenty participants wore CRT (Paragon Vision Sciences, Mesa, AZ) HDS 100 contact lenses on one eye and control lenses on the contralateral eye for one night while sleeping. Another 24 participants wore CRT lenses on both eyes for one night. Central corneal thickness was measured using optical coherence tomography and Orbscan II on the night before lens use, immediately after lens removal on the following morning, and 1, 3, 6, and 12 hours later. By using optical coherence tomography as a reference, the adjusted AF was calculated by using a least squares method over time. RESULTS: The adjusted AF depended on the corneal thickness in normally hydrated corneas. The adjusted AF and the percentage change of the adjusted AF varied before and after overnight lens wear. There was a strong and significant correlation between the corneal swelling and the percentage change of the adjusted AF (all r at least 0.91, P<0.05). CONCLUSIONS: The adjusted AF is a variable, not a constant. The AF is a function of the corneal thickness and its alteration with, for example, corneal swelling. The validity of the adjusted Orbscan II pachymetric measures using a single AF is untenable.
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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 | 0.006 | 0.020 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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; a candidate call from one teacher head, not a consensus.
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".