Pre-Cut DSAEK Tissue: How Much Swelling Occurs in Storage and Does it Matter?

Abstract

Purpose: : To compare DSAEK donor tissue pachymetry values measured immediately after microkeratome preparation by Ocular Systems, Inc (OSI) to pachymetry measurements of the same tissue 24 hours later in the operating room, and to compare the donor dislocation rates of pre-cut tissue with surgeon cut tissue.

Methods: : A retrospective review of DSAEK cases performed by a single surgeon (NBG) using a standard technique from June 2006 to October 2007 was performed. Fifty-eight donor corneas were prepared by OSI using a Moria CB microkeratome and Moria artificial anterior chamber. Immediately after dissection, pachymetry measurements of the posterior lamellar tissue were taken using a single ultrasound pachymeter. The entire donor specimen was deposited in Optisol GS^TM for transfer to the operating room. All tissue was used within 24 hours of preparation. Pachymetry values were repeated in the operating room by a single surgeon (NBG) just before use with the tissue mounted on the same Moria chamber. The two pachymetry values were then compared to evaluate the amount of posterior lamellar tissue swelling that occurred during storage. The dislocation rate in this pre-cut group was determined and compared to the dislocation rate of 83 cases using surgeon-cut tissue performed during the same time frame with the same technique.

Results: : The average posterior lamellar tissue thickness was 123 microns just after tissue preparation in the eye bank. The average thickness once this tissue reached the operating room was 163 microns, representing an average increase in graft thickness of 33%. The graft dislocation rate in this group was 15.5% and the graft failure rate was 5%. The dislocation rate of the 83 DSEK cases using surgeon cut tissue was 5% with a 4% graft failure rate. The difference in dislocation rates was statistically significant.

Conclusions: : Tissue swelling occurs when precut DSAEK donor tissue is stored in Optisol transport solution for <=24 hours. This swelling may contribute to the observed increase in donor dislocation rate observed in pre-cut tissue compared to surgeon cut tissue.

Keywords: transplantation • cornea: storage • clinical (human) or epidemiologic studies: systems/equipment/techniques