Influence of processing-to-transplantation interval on DSAEK graft survival: a 3.5-year retrospective analysis at King Abdulaziz Medical City

Descemet stripping automated endothelial keratoplasty (DSAEK) outcomes are highly contingent on donor endothelial viability. For international tertiary centers, reliance on imported pre-cut donor tissue introduces unavoidable logistical delays. This study investigates the impact of the processing-to-transplantation time (PTT) on long-term DSAEK graft survival within an international procurement model. This retrospective cohort study evaluated 92 consecutive patients who underwent DSAEK at a tertiary care center in Saudi Arabia over a 3.5-year period (January 2022–July 2025), representing the patient enrollment window rather than individual follow-up duration. All pre-cut donor tissues were sourced from a single international eye bank (USA) via cold-chain transport. The primary outcome was graft survival. Survival probabilities were estimated using Kaplan–Meier analysis. A Cox proportional hazards model was utilized to identify independent predictors of graft failure, evaluating PTT, death-to-preservation (DTP) time, recipient age, baseline endothelial cell density, and recipient glaucoma status. Kaplan–Meier analysis demonstrated numerically reduced survival with increasing PTT, with restricted mean survival times of 909.2 days for PTT ≤ 3 days, 841.3 days for 4–5 days, and 765.3 days for ≥ 6 days; however, the difference was not statistically significant ( p = 0.777). In multivariable Cox regression, PTT was not an independent predictor of graft failure (HR 1.10 per day; 95% CI 0.82–1.48; p = 0.51). Glaucoma was also not significantly associated with failure (HR 1.60; 95% CI 0.62–4.14; p = 0.33). ROC analysis showed limited discriminatory ability of PTT (AUC = 0.611), with an optimal cutoff of ≥ 4.5 days demonstrating high specificity but limited sensitivity. Prolonged PTT was not independently associated with an increased risk of graft failure within the observed range. Recipient glaucoma status was also not independently associated with graft failure. In international settings, these findings suggest that graft survival may be maintained across the PTT range achievable under current cold-chain procurement conditions. Larger prospective studies are warranted to confirm these findings.