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Abstract #8190 Published in IGR 4-3
Ageing of Schlemm's canal in nonglaucomatous subjects
Boldea RC; Roy S; Mermoud AInternational Ophthalmology 2002; 24: 67-77
AIM: To study age-related Schlemm's canal endothelial changes and evaluate the consequences on filtration function. MATERIAL AND METHODS: The inner wall endothelium of Schlemm's canal was examined in nine non-glaucomatous subjects aged between 32 and 75 years, by a combined technique of light and electron microscopy (scanning and transmission). Quantitative analysis included counts of bulges, pores, nuclei, giant vacuoles, and other protruding structures, as well as measures of pores, giant vacuoles and Schlemm's canal size parameters (diameter and inner wall width). Outflow facility calculations were realized using a modified previously-described mathematical model. RESULTS: The main structures affected by aging in Schlemm's canal appeared to be giant vacuoles. Their density but also their size is significantly reduced with increasing age. The intracellular pore population is also found to diminish with age and is correlated to that of giant vacuoles, suggesting that these pores are luminal openings of vacuoles. Outflow facility calculations revealed a global decrease of endothelial outflow facility of about 60% between the third and seventh decades. The study also showed a different age-related pattern for the two subtypes of endothelial pores. CONCLUSIONS: This study demonstrated that Schlemm's canal filtration function is significantly influenced by age, as the endothelial inner wall outflow facility is found to be widely reduced. This is partly the result of an age-related reduction in counts of giant vacuoles and intracellular pores. The second pore population (border or intercellular) does not follow the same evolution, but may have a more significant regulator role in transendothelial permeability.
A. Mermoud, MD, Glaucoma Unit, Hôpital Ophtalmique Jules Gonin, Avenue France 15, 1004 Lausanne, Switzerland
Classification:
2.5 Meshwork (Part of: 2 Anatomical structures in glaucoma)
3.2 Electron microscopy (Part of: 3 Laboratory methods)
