Hypothesis
Adding partial endothelial trepanation to anterior lamellar keratoplasty would be at least as safe as big-bubble deep anterior lamellar keratoplasty, with fewer conversions to a full-thickness corneal graft.
What failed
Only 14 eyes of 14 patients were enrolled. Conversion to full thickness happened in 5 of 13 surgeries (3 DALK, 2 PET; p = .592), and no secondary outcome differed between groups. The trial was terminated for low inclusion and lack of equipoise, leaving the primary outcome underpowered.
Broken assumption
Partial endothelial trepanation makes anterior lamellar keratoplasty safer against full-thickness conversion.
Why
The authors state no conclusions can be drawn on the primary outcome from this underpowered trial, but that the PET technique was not as safe as expected; they report the results as an ethical obligation.
From the published paper: Wisse et al. Journal of Trial and Error, 2025. ↗CC BY