Residual ethanol content of donor sclera after storage in 95% ethanol and saline rinse of various durations

PURPOSE: Some surgeons are wary of using alcohol-preserved sclera for allog rafts because they fear a toxic effect on surrounding tissue after placemen t. We set out to determine the amount of ethanol remaining in scleral allog raft material after storage in 95% ethanol. METHODS: Sixty half scleras from 30 donors were pre served in 95% ethanol f or an average of 31 +/- 14 days (range, 11 to 50 days). Rehydration was per formed by soaking each half sclera in 4 ounces of balanced salt solution, H alf scleras were randomly assigned to six groups of 10 each. Assays for eth anol were performed on the following groups: no balanced salt solution soak and balanced salt solution soak for 10 minutes, 20 minutes, 30 minutes, 40 minutes, and 50 minutes. Ethanol assay was performed by Headspace Gas Spac e Chromatography at ChemaTox Laboratory, Inc, Boulder, Colorado. RESULTS: The 10 half scleras without balanced salt solution soak had a mean (+/- SD) ethanol level of 175 +/- 14.1 mg per g of sclera. After 10 minute s of balanced salt solution soak, the level decreased to 7.57 +/- 1.56 mg p er g, then 3,77 +/- 3,02 mg per g at 20 minutes, 1.59 +/- 0,61 mg per g at 30 minutes, 1.07 +/- 0.30 mg per g at 40 minutes, and 0.96 +/- 0,26 mg per g at 50 minutes. Approximately 96% of the ethanol is leeched out of the hal f sclera by 10 minutes and 98% by 20 minutes. CONCLUSIONS: For sclera preserved in 95% ethanol, soaking in balanced salt solution for 20 minutes or longer leeches approximately 98% of the ethanol from the preserved donor sclera, (Am J Ophthalmol 1999;128: 522-524. (C) 19 99 by Elsevier Science Inc. All rights reserved.).