Elastosis of the lamina cribrosa in glaucomatous optic neuropathy

The purpose of this study was to determine whether elastotic degeneration of the elastin component of the lamina cribrosa occurs in optic neuropathy associated with different types of glaucoma. Human optic nerve heads with primary open-angle, neovascular, chronic angle closure and pseudoexfoliation glaucoma, and with varying duration of disease were compared with age-matched normal eyes, using electron microscopy and immunogold labeling of elastin. The percent area occupied by immunogold labeled elastin material was determined using a digital image analysis system. In all eyes with a history of glaucoma, elastosis was found in the lamina cribrosa and there was a significantly greater percentage of area occupied by elastin compared with age-matched control eyes (P < 0.0001). Among the glaucomatous eyes, pseudoexfoliation glaucoma had the largest area of elastosis, followed by primary open-angle and secondary glaucoma (neovascular and chronic angle closure). In all glaucoma samples, large, confluent elastin aggregates of irregular and varied shapes (elastosis) were observed in the lamina cribrosa and insertion region. These results demonstrate that glaucomatous optic neuropathy is associated with elastosis of the lamina cribrosa, which may contribute to the changes in compliance of the optic nerve heads of glaucomatous eyes.