The Cornea Preservation Time Study (CPTS) was a nationwide study with 40 participating clinical sites, including over 70 corneal surgeons, and 23 participating eye banks.  It was the first of its kind to study whether endothelial keratoplasty (a corneal transplant surgery) using donor corneas preserved beyond 8 days may be as successful as a surgery using donor corneas preserved less than 8 days.

CPTS was scientifically reviewed and approved by many expert groups and was funded by the National Eye Institute, a Division of the National Institutes of Health of the U.S. Department of Health and Human Services, a part of the federal government.   1,330 study eyes were  enrolled in the study and underwent surgery.   Dr. Jonathan Lass was the study chair for the CPTS and is a professor at Case Western Reserve University (CWRU) in Cleveland, Ohio.  Allison Ayala, MS was the Principal Investigator of the Data Management and Analysis Center located at the Jaeb Center for Health Research in Tampa, Florida. CWRU and the Jaeb Center worked jointly to run this study.


Click the link below to hear an episode of "As Seen from Here," a podcast from ASCRS, featuring Study Chair Jonathan H. Lass, MD

Program #418: Endothelial Cell Density and DSAEK


Click on the link below to watch a video introduction from the Study Chair

CPTS Video Introduction from Study Chair

Click the link below to view CPTS Eye World Article

CPTS Eye World Article

Click the link below to hear a JAMA Ophthalmology interview with the Study Chair, Jonathan H. Lass, MD

Donor, Recipient, and Operative Factors Associated with Increased Endothelial Cell Loss in the CPTS

Click the link below to view an AAO interview with the Study Chair, Jonathan H. Lass, MD 

CPTS: Factors Affecting Graft Success