Differences between phoria and vergence adaptation in myopic children with esophoria
Bibliographic record
Abstract
We previously showed that myopic children with normal near phorias exhibit reduced phoria adaptation compared to emmetropes (V Sreenivasan, EL Irving, WR Bobier, 2009). Here, we report the adaptive behavior of myopic esophores when they sustain near fixation without and with +2D adds. Eleven emmetropic phoria-normals (EMM; 0–8△exo) and 8 myopic-esophores (ME; 2–8eso) between 7–14 years fixated a high-contrast near target (33 cm) with and without +2D lenses for 20 minutes. Phoria adaptation (PA) was quantified through changes in near phoria, measured using the modified Thorington technique. Tonic vergence adaptation (TVA) was determined by measuring tonic vergence (distance phoria through 0.5mm pupils) before and after the near-task. Accommodative adaptation was evaluated by measuring pre and post-task tonic accommodation using a 0.5 cpd difference of Gaussian target. No add condition: The mean baseline near phoria was 4.48 (eso) ±0.57△ in ME and −3.54 (exo) ±0.86△ in EMM. Following sustained fixation, the near phorias significantly (p<0.05) declined in both groups (EMM: Exo reduced by 1.09±0.3△; ME: Eso reduced by 2.19±0.49△). Tonic vergence showed a convergent shift (p<0.05) post-task in both groups (EMM: 1.54±0.6△; ME:1.16±0.52△). Accommodative adaptation was greater in ME compared to EMM (EMM: 0.18±0.12D; ME:0.47±0.10D). ME showed higher response-AC/A ratios than emmetropes (EMM:3.76±0.48△/D; ME:6.45±0.89△/D; p<0.01). Add condition: +2D lenses caused a divergent shift in the near phoria (EMM: 4.61±0.33△; ME:6.67±0.58△; p<0.01) in both groups. Sustained fixation significantly (p<0.001) reduced the divergent shift in both groups, but significantly less in the ME (EMM: 4.23±0.13△; ME:1.93±0.16△; p<0.01). Post-task tonic vergence showed a convergent shift in both groups (EMM: 1.10±0.30△; ME:0.54±0.60△) while tonic accommodation showed no change in EMM (0.02±0.08D) and a small increase (myopic shift) in ME (0.25±0.16D). When near fixation is prolonged with and without +2D near adds, TVA moved toward a more convergent position in both groups. However, PA shifted in the opposite direction when ME sustained fixation through their habitual correction. The shift in PA was possibly influenced by the differing accommodative parameters seen in ME. Reducing accommodative activity through near adds reduced this effect. PA can be opposite to the direction of TVA and appears to act primarily to reduce the phoria (orthophorization).
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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".