Optical Microscopy Study of Human Sclera Stored in Different Media

Purpose To describe microscopic changes in the structure of human sclera immediately after enucleation (negative control group) and to compare them after being stored for three months in four different media: pure glycerin, absolute alcohol, benzalkonium chloride diluted in absolute alcohol (1:5000), and benzalkonium chloride diluted in balanced salt solution (1:5000). The comparison took into consideration their final state of conservation. Design Experimental study, laboratory investigation. Methods Optical microscopy was used to study the specimens after they had been in storage for one, two, and three months. The scleral fragments were prepared in thin plates, dyed, and then submitted to histologic analysis by two masked specialists. Unpreserved scleral fragments obtained right after enucleation were assessed and served as negative controls. Results The collagen fibers of scleras stored in glycerin presented with a more regular pattern, closer in appearance to the negative control group. Scleras stored in the other three media presented contorted collagen fibers. Conclusions Our findings suggest that glycerin is close to being the ideal storage medium for sclera, because it maintains the structural characteristics of the collagen fibers. Research is ongoing to determine how to increase the bactericidal and antiviral properties of glycerin storage.