Age related changes in the non-collagenous components of the extracellular matrix of the human lamina cribrosa
- aDepartment of Optometry and Vision Science, Cardiff University, bDepartment of Ophthalmology, Leicester Royal Infirmary, Leicester, cDepartment of Ophthalmology, Bristol Eye Hospital, Bristol, dCollagen Research Group, University of Bristol, Langford, Bristol, eSchool of Biosciences, Cardiff University
- Dr Julie Albon, Department of Optometry and Vision Science, Cardiff University, Redwood Building, King Edward VII Avenue, PO Box 905, Cardiff CF1 3XS
- Accepted 1 October 1999
Abstract
AIMS To investigate age related alterations in the non-collagenous components of the human lamina cribrosa.
METHODS Fibronectin, elastin, and glial fibrillary acidic protein (GFAP) staining were assessed in young and old laminae cribrosae. An age range (7 days to 96 years) of human laminae cribrosae were analysed for lipid content (n=9), cellularity (n=28), total sulphated glycosaminoglycans (n=28), elastin content (n=9), and water content (n=56), using chloroform-methanol extraction, fluorimetry, the dimethylmethylene blue assay, and ion exchange chromatography, 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 that elastin content increased from 8% to 28% dry tissue weight, total sulphated 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 metabolic state of the lamina cribrosa as it ages, and may contribute to changes in mechanical integrity. Such changes may be implicated in the susceptibility of the elderly lamina cribrosa and also its response to glaucomatous optic neuropathy.
