Biomechanical and histological evaluation of glycerol-preserved human sclerae.

PURPOSE To determine the histological and biomechanical characteristics of glycerol-preserved human sclera. METHODS A total of 114 paired human sclerae were cleaned and preserved with 98% glycerol under refrigeration at 4 to 8 degrees C. The samples were divided into a control group with no preservation and 5 groups of 19 sclerae in 7, 15, 30, 90 and 180 days of preservation. Each specimen was submitted to histological examination and tested for traction distensibility functions. RESULTS Preservation in glycerol did not cause alterations in the histological architecture of the scleral tissue. The mean load required to break the scleral tissue increased according to preservation time as a sigmoid function. A significant increase in mechanical resistance and decrease in distension of scleral tissue occurred after 90 days of preservation. CONCLUSIONS Scleral preservation in glycerol keeps tissue integrity. The preserved material is less distensible after 90 days. Surgeons who use sclera in ophthalmic procedures should be aware of the mechanical characteristics of glycerol-preserved sclera and take into account tissue preservation time.