Age related changes in the non-collagenous components of the extracellularmatrix of the human lamina cribrosa

Aims-To investigate age related alterations in the non-collagenous componen ts of the human lamina cribrosa. Methods-Fibronectin, elastin; and glial fibrillary acidic protein (GFAP) st aining were assessed in young and old laminae cribrosae. An age range (7 da ys to 96 years) of human laminae cribrosae were analysed for lipid content (n=9), cellularity (n=28), total sulphated glycosaminoglycans (n=28), elast in content (n=9), and waiter content (n=56), using chloroform-methanol extr action, fluorimetry, the dimethylmethylene blue assay, and ion exchange chr omatography, respectively. Results-Qualitatively, an increase in elastin and a decrease in fibronectin and GFAP were demonstrated when young tissue was compared with the elderly . Biochemical analysis of the ageing human lamina cribrosa demonstrated tha t elastin content increased from 8% to 28% dry tissue weight, total sulphat ed glycosaminoglycans decreased, and lipid content decreased from 45% to 25 %. There were no significant changes in total cellularity or water content. Conclusion-These alterations in composition may be indicative of the metabo lic state of the lamina cribrosa as it ages, and may contribute to changes in mechanical integrity. Such changes may be implicated in the susceptibili ty of the elderly lamina cribrosa and also its response to glaucomatous opt ic neuropathy.