Effect of Corneal Preservation Time on Long-Term Graft Success Cornea Preservation Time Study (CPTS) Protocol

The CPTS is a randomized, controlled clinical trial examining the impact of preservation time on graft failure and endothelial cell density following endothelial keratoplasty EK. The study has been designed so that the surgeons and eye banks can follow and provide their usual surgical and post-operative procedures and care to study participants with the exception of assignment of donor tissue. Study eyes will be randomly assigned to receive a donor cornea from preservation date to surgery date of 8 to 14 days or a donor cornea from preservation date to surgery date of 7 or fewer days, with a comparable death to preservation time for both groups. Surgeons and study participants are masked to time from preservation to surgery. Subject participation will consist of examined at a baseline/enrollment visit, at the time of EK surgery, and at post-operative visits at 1 day, 1 week, 1 month, 6, 12, 24, and 36 months in addition to any routine care visits. Eye bank will follow their procedural routine for procurement of tissue and determining its suitability for EK, including prior LASIK or photorefractive keratectomy donors, in accordance with the Medical Standards and Procedure Manual of the EBAA(19,20). This includes standard serologic testing, specular microscopy, and slit lamp examination. OBJECTIVES: To determine if the 3-year graft failure rate following EK performed with donor corneas with a preservation time of 8 to14 days is non-inferior to the failure rate when donor corneas with a preservation time of 7 or fewer days are used. To determine if the central corneal endothelial cell density 3-years after EK is related to preservation time. To evaluate the effect of donor, operative and postoperative factors on graft failure and endothelial cell density three years following EK.