[Organ culture for preservation of the cornea: human umbilical cord serum versus fetal bovine serum].

Objective: To evaluate the changes of porcine corneal endothelium, the morphology, histology, ultrastructure, enzymes activity and metabolism of the cornea induced by organ culture with two different media containing fetal bovine serum (FBS) or human umbilical cord serum (HCS).
Methods: Fifty pairs of porcine corneas were preserved at 31 degrees C for 7, 14, 21, 28 days. One cornea of each pair was cultivated in medium I containing 10% FBS (group 1); the other one was stored in medium II containing 10% HCS (group 2). Thirteen fresh porcine corneas served as controls. All stored corneas were dehydrated for 24 hours. Twelve corneas from each group were evaluated each week, including the morphology, histology and enzyme histochemical staining of the cornea. Scanning electron microscopy was performed on one cornea from each group at 14 and 28 days and compared with the fresh cornea. pH value, glucose and lactate concentration of the culture media before and after culture were examined. Microbiological evaluation was also performed.
Results: Endothelium evaluation did not differ statistically between the two groups of porcine corneas. The morphological endothelium study showed some alterations such as pleomorphism. After 28 days of cultivation, the mean cell losses of endothelium were 10.98% and 10.85% in medium I and medium II stored corneas, respectively. There were no statistical differences of the histology, ultrastructure and enzymes activity of corneas between the two groups. The histological study showed corneal swelling and epithelial sloughing after preservation. Scanning electron microscopy showed an intact endothelial layer in all corneas. Enzyme histochemical staining showed vigorous enzyme activity in the corneal epithelium and endothelium. Enzyme activity in stroma decreased with preservation time. Corneas showed good glucose metabolism. Incidence of contamination was 6% for storage medium.
Conclusions: The corneal endothelium can maintain a good viability for 4 weeks in these two organ culture media. HCS can replace FBS in the organ culture medium.