Long-term outcomes following primary versus secondary Boston keratoprosthesis type 1 implantation
Bibliographic record
Abstract
BACKGROUND/AIMS: To compare long-term outcomes of primary versus secondary (postgraft failure) Boston keratoprosthesis type 1 (KPro) implantation. METHODS: Medical records of patients at the Centre hospitalier de l'Université de Montréal having undergone KPro implantation between 2008 and 2017 were reviewed and included if they had a preoperative Snellen best-corrected visual acuity (BCVA) of 20/100 or worse and a minimum of 5 years of follow-up. Eighty-two eyes were separated into two cohorts (40 primary, 42 secondary KPro) and BCVA, complications and device retention were evaluated between groups. RESULTS: BCVA improved from baseline in both groups at each year; this was significant at all five postoperative years in the primary group and the first 3 years in the secondary group (p<0.05). Mean BCVA was similar between groups at 5 years (logarithm of minimal angle resolution 1.3±0.8 in the primary group vs 1.5±0.8 p<0.05). Idiopathic vitritis, choroidal detachment and new glaucoma occurred more after primary KPro (n=7, 17.5% vs n=1, 2.4%; n=11, 27.5% vs n=3, 7.14% and n=14, 35% vs n=6, 14%, respectively; p<0.05). Primary KPro had lower retention (n=28, 70% vs n=38, 91%, p<0.05) at final follow-up. There was more aniridia in the primary group (n=19, 48% vs n=6, 14%, p<0.01). Within each group, 50% of removals occurred in aniridic eyes. CONCLUSION: Primary KPro yielded favourable long-term visual outcomes but had more complications and lower retention rates than secondary KPro, likely explained by preoperative indications. Primary device implantation represents a favourable option for patients for whom grafts are likely to fail.
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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 | 0.000 |
| 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 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".