Abstract
Abstract: :
Purpose: On gross inspection of scleral shells stored in glycerin for 9 to 19 years, we observed a brown discoloration in some specimens, and wondered whether this was due to oxidation and whether it could be reversed, or whether there was ultrastructural change preventing proper hydration. We also observed pigment on the inner surface & linear structures within some specimens that could not be detected on SEM, but wondered whether this could be identified by standard histopathology and TEM. Methods: We soaked strips of brown discolored sclera in solutions of various antioxidants (glutathione, superoxide dismutase, catalase & dimethylthiourea)including controls soaked in a commercially available balanced salt solution with glutathione, and examined portions of sclera by light microscopy after standard histochemical preparation, and with transmission electron microscopy. Results: Specimens showed some whitening after soaking in these antioxidants, but often the same as controls soaked in the commercially available solution. The external surface of sclera often whitened more than its inner (uveal) surface. Uveal pigment, uveal & retinal cells, and intrascleral nerves & vascular structures were identified on light & transmission electon microscopy. Conclusions: The current method of reconstitution of scleral shells stored in glycerin seems adequate, without the addition of other antioxidants. The brown discoloration after prolonged storage may not be totally reversed, and may be due to factors other than just oxidation.
Keywords: sclera • antioxidants • microscopy: light/fluorescence/immunohistochemistry