Factors associated with thickness of eye bank-prepared DSAEK graft tissue

Purpose: To identify factors associated with corneal thickness of eye bank-prepared lamellar tissue for endothelial keratoplasty. Methods: Data from all corneal tissues processed for DSAEK (Descemet stripping automated endothelial keratoplasty) at a single eye bank from 2008-2012 were included. Multivariable linear regression models were used to identify factors contributing to DSAEK graft thickness. Results: Eye bank-prepared DSAEK grafts have become thinner over time, on average 48 microns thinner in 2012 than in 2008. Decreased pre-processing corneal thickness and higher pre-processing endothelial cell density were associated with thinner lamellar grafts (p<0.0001). Older donor age was associated with thinner grafts (p<0.0001). There was no significant interaction between donor age and endothelial cell density in relation to graft thickness (p=0.16). Grafts processed during the “workday” (8a-5p, n=5,397) were on average 3.8 microns thinner than those processed “after-hours” (5p-8a, n=1,897; p<0.0001). Death-to-procurement time and death-to-processing time were not associated with graft thickness (p=0.94 and p=0.93). In comparing technician experience, no significant difference was found between number of tissues processed and DSAEK graft thickness. Conclusions: Eye bank-prepared DSAEK graft thickness has decreased during the five year study period, likely reflecting surgeon preference. Thinner grafts were associated with thinner initial corneal tissue thickness, higher endothelial cell density, increased donor age, and daytime tissue preparation. There was no association between graft thickness and death-to-procurement time, death-to-processing time, or technician experience. While the identified associations show statistical significance, no individual association conveys substantial clinical significance.