[New osmotic additives to culture media for corneal preservation]

We investigated the effect of hyaluronic acid, molecular weight 250,000 and 500,000 as an osmotic additive to corneal preservation media. Porcine corneal specimens were incubated in organ culture for 8 days, followed by endothelial cell count and ultrasonic pachymetry. The preservation medium MEM-Earle with 2% FCS contained either no additives, 6% dextrane, MW 500,000 2% chondroitin sulfate, 1% hyaluronic acid MW 250,000, or 1% hyaluronic acid, MW 500,000. Whereas corneal thickness was estimated to be about 4 mm in the group without osmotic additives, all other media kept the corneas thin between 700 and 760 microns. The endothelial cell counts after preservation were similar in all groups. As hyaluronic acid is a physiological substance of the eye, it may offer some advantages for corneal perservation.