KERATAN SULFATE IN THE TRABECULAR MESHWORK AND CORNEA

Purpose. A study was made of the distribution of keratan sulphate in t he human anterior chamber. Methods. The monoclonal antibody, 5-D-4, wa s used in immuno-electron microscopy to visualise keratan sulphate dis tribution in the anterior chamber of 16 normal eyes, 7 Fuchs' dystroph y corneas, and a macular dystrophy cornea. Results. Keratan sulphate w as detected in normal human aqueous humour and also on the surface of trabecular cells in the uveal meshwork. Normal corneal stroma showed a n increase in keratan sulphate labelling from anterior to posterior, w ith marked labelling in the posterior region of Descemet's membrane. T he apical surface of the corneal endothelium labelled positively, but showed considerable variation in the level of labelling from cell to c ell. The macular dystrophy cornea had the classic histopathological fe atures of a type I case, including a highly abnormal Descemet's membra ne. No keratan sulphate was detected in the macular dystrophy patient' s corneal stroma or serum. The Fuchs' endothelial dystrophy corneas sh owed a normal distribution of keratan sulphate labelling in the stroma . The Fuchs' endothelial cells labelled for keratan sulphate but were highly abnormal in appearance, often exhibiting long filopodia and app earing to be actively migrating. Conclusions. This work has shown that keratan sulphate has a much wider distribution than was previously be lieved. The detection of keratan sulphate on the trabecular and endoth elial cell surfaces also suggests a possible role for this molecule in cell adhesion and/or migration.