Rapid warming protocol cuts down on evaluation times for donor corneal tissue

Investigators retrospectively assessed the effect of a rapid tissue warming protocol on tissue evaluation times and specular image quality.

Study design

Donor corneas at a single eye bank were collected and stored in Optisol-GS. The analysis compared tissue samples before and after the facility implemented a rapid tissue warming protocol. Each group included 247 different corneas.

Prior to implementing the rapid protocol, corneas were thawed at room temperature. With the rapid warming protocol, technicians removed samples from cold storage and placed the grafts in an incubator for 1.25 to 1.5 hours.

Outcomes

Implementing the rapid warming protocol reduced both the average specular image acquisition time (3:1 hours vs. 1:5 hours; P<0.01) and total evaluation time (4:1 hours vs. 3:1 hours; P<0.01). There was also a 20% decrease in the number of corneas exposed to more than 1 warming cycle (97% vs. 73%).

Specular image quality was also rated higher in the rapid warming group (P<0.01) despite similar donor characteristics. There were no fungal infections reported in either group.

Limitations

Despite a reduced tissue evaluation time, almost two-thirds of corneas were exposed to more than 1 warming cycle. Since the Eye Bank Association of America does not require time tracking between cold storage to evaluation, the control group’s times were estimated based on arrival time to the eye bank and that office’s standard operating procedure. Warming times may also be overestimated because time in cold storage prior to evaluation was not considered.

Clinical significance

Rapid tissue warming protocols may reduce tissue evaluation time, number of warming cycles, and improve the quality of specular images. It may also optimize technician work-flow, as well as minimize unfavorable storage temperatures and tissue handling. It is unclear, however, if controlled tissue warming times will affect postoperative fungal infections.