The Effects of Epithelium-off Corneal Collagen Cross-linking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus
Bibliographic record
Abstract
ABSTRACT Purpose To utilize Scheimpflug imaging to describe corneal changes in keratoconic patients undergoing collagen cross- linking. Study type Case series. Study design Retrospective chart review at two sites: Calgary, Alberta and Brandon, Manitoba, Canada. All patients were diagnosed with keratoconus and had undergone corneal collagen crosslinking. All patients had pre- and post-procedure imaging done with Oculus Pentacam. Results Sixty-one eyes of 48 patients with 6 months follow- up and 36 eyes of 27 patients with one year follow-up were included. Average age was 27 ± 12 years (15-48 years). Fifty- one males and 10 females were studied. At 1 year follow-up, all Pentacam indices were found to improve: ISV −4.44 ± 18.6 (p = 0.16), IVA −0.07 ± 0.27 (p = 0.12), KI −0.009 ± 0.082 (p = 0.49), CKI −0.012 ± 0.027 (p = 0.01), IHA −3.87 ± 23.3 (p = 0.33) and IDH −0.062 ± 0.308 (p = 0.24). Keratometry measurements were flatter at the pupil centre by 0.87 ± 2.53 D (p = 0.05). Kmax and Kmin were flatter by 0.58 ± 1.37 D (p = 0.02) and 0.33 ± 1.70 D (p = 0.25) respectively. Pupil center pachymetry was thinner by 12.9 ± 21.1 µm (p = 0.0006) at 6 months, as were the corneal apex and thinnest local by 12.9 ± 22.3 µm (p = 0.001) and 21.8 ± 54.6 µm (p = 0.05) respectively. However, all central pachymetry readings were not statistically different from baseline at the one year measurements. Peripheral corneal measurements at 6 mm diameter were no different from baseline at 6 months, however, were significantly thicker at the 1 year follow-up. Conclusion The data, in this study, points to a more uniform cornea post corneal collagen crosslinking. The inferior cornea becomes flatter and superior cornea steeper with less variation when comparing the corneal curvatures. The peripheral cornea becomes thicker at 1 year post-procedure. Collagen cross- linking stabilizes the cornea. How to cite this article Penner V, Muzychuk A, Al-Ghoul A, Rocha G. The Effects of Epithelium-off Corneal Collagen Crosslinking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus. Int J Kerat Ect Cor Dis 2014;3(3):113-117.
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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 | 0.002 |
| 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) | 0.001 | 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".