Corneal preparation of eye bank eyes for experimental surgery

To evaluate the efficacy of dextran in balanced salt solution (BSS) as a preparation of eye bank corneas for experimental surgeries.

We used 12 eye bank eyes that were unsuitable for transplant. The corneas were removed from the globe and affixed to a Hanna artificial anterior chamber. Four concentrations of dextran-BSS (10%, 15%, 20%, and 30% [+/-0.56%]) were used to dehydrate the corneas, and corneal thickness was assessed with an ultrasonic pachymeter (+/-5 microm) at varying time-intervals over 3 hours.

The corneas were thinned to an average thickness of 477+/-54 microm, 430+/-54 microm, 406+/-61 microm, and 391+/-52 microm at average times of 75+/-0 minutes, 85+/-23 minutes, 60+/-12 minutes, and 45+/-0 minutes for the 10%, 15%, 20%, and 30% concentrations, respectively. Corneal thickness was stabilized in both a 15% and a 20% solution. The data was fit to exponential curves until a minimum value was reached, after which linear regression analysis was used to determine the slopes of the data. The slopes for the 15% and 20% concentrations were not significantly different from 0 (p = 0.5 and p = 0.4, respectively). The slopes for each set of data from the 10% and 30% concentrations were significantly different from each other (p = 0.010 and p = 0.001, respectively).

A solution of 20% dextran in BSS is effective for dehydrating eye bank corneas to a quasi-normal physiologic thickness and for maintaining the thickness for a sufficient amount of time. Both the posterior and anterior sides of the cornea should be exposed to the solution for 60 minutes.