The Relationship Between Eyebrow and Eyelid Position in Patients With Ptosis, Dermatochalasis and Controls
Bibliographic record
Abstract
PURPOSE: The purpose of this study is to explore mechanical and co-innervational factors involved in both voluntary and involuntary brow elevation among people affected by ptosis and dermatochalasis. METHODS: In this prospective cohort study of normal controls and eyelids with ptosis or dermatochalasis, marginal reflex distance (MRD1) and brow height were measured under the following conditions: neutral position, involuntary mechanical brow elevation, voluntary brow elevation, and maximal eyelid opening. The primary outcome measure was change in MRD1. Secondary outcome measures included brow height and coupling (mm brow height change per mm MRD1 change). Analysis of variance and t tests were performed for intra- and intercondition comparisons, respectively. RESULTS: Mechanical (involuntary) brow elevation significantly raised MRD1 in control eyelids and eyelids with dermatochalasis, but not in eyelids with ptosis. Voluntary brow elevation produced significantly greater brow height than maximal eyelid opening in controls and eyelids with dermatochalasis, but not in eyelids with ptosis. Maximal eyelid opening increased MRD1 greater than voluntary brow elevation significantly in control eyelids, but not in eyelids with dermatochalasis or ptosis. Coupling of the brow and eyelid margin during maximal eyelid opening was significantly greater in eyelids with ptosis relative to controls. CONCLUSIONS: In eyelids with ptosis, mechanical brow elevation does not change eyelid position; however, voluntary brow elevation raises eyelid position to a similar position as maximal eyelid opening. These results argue against the contention that the brow is elevated to mechanically lift the eyelid in ptosis and instead suggest that the brow elevation is driven by efforts to raise the eyelid, possibly via co-innervation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".