Prelamellar dissection donor corneal thickness is associated with Descemet stripping automated endothelial keratoplasty operative complications in the cornea preservation time study

Purpose: To identify donor and recipient factors, including eye bank tissue observations, predictive of operative complications in the Cornea Preservation Time Study. Methods: One thousand three hundred thirty study eyes undergoing Descemet stripping automated endothelial keratoplasty for Fuchs dystrophy or pseudophakic/aphakic corneal edema were randomized to receive a donor cornea with preservation time (PT) of 0 to 7 days (N = 675) or 8 to 14 days (N = 655). Donor factors included demographics, prelamellar corneal and postlamellar lenticule dissection thickness, central endothelial cell density, and tissue processing time. Recipient factors included demographics, intraocular pressure, and glaucoma medications or surgery (trabeculectomy, laser trabeculoplasty). Eye bank observations included donor tissue folds, pleomorphism/polymegethism, and endothelial cell abnormalities. Possible tissue-related operative complications were recorded including difficult donor lenticule unfolding and positioning. Multivariable logistic regression with backward selection was used to identify statistically significant (P, 0.01) associations between factors and operative complications. Results: The only factor predictive of operative complications [58 (4.4%) of 1330 surgeries] was prelamellar dissection donor corneal thickness (P = 0.002). For every 50 mm of donor corneal thickness prior to lamellar dissection, operative complication odds increased by 40% (odds ratio [99% confidence interval (CI)]: 1.40 [1.06-1.83]) adjusting for PT and whether the epithelium was on or off. The estimated mean prelamellar dissection donor corneal thickness for PT 0 to 7 days was 537 mm (99% CI: 516 mm-558 mm) compared with 567 mm (99% CI: 546 mm-588 mm) for PT 8 to 14 days (P, 0.001). Conclusions: Thicker donor tissue (prelamellar dissection) is associated with operative complications and should be considered in tissue selection for Descemet stripping automated endothelial keratoplasty lenticule preparation.