Glaucoma is a common disease that leads to loss of peripheral vision and, if left untreated, ultimately to
blindness. While the exact cause(s) of
glaucoma is still unknown, two leading risk factors are age and elevated intraocular pressure. Several studies suggest a possible link between
glaucoma and
inflammation in humans and animal models. In particular, our lab recently identified a T104M mutation in
IL-20 receptor-B (IL-20RB) in
primary open angle glaucoma patients from a large pedigree. Several of the
interleukin- (IL-) 20 family of
cytokines and receptors are expressed in ocular tissues including the trabecular meshwork, optic nerve head, and retinal ganglion cells. The DBA/2J mouse develops high intraocular pressures with age and has characteristic optic nerve defects that make it a useful
glaucoma model. IL-24 expression is significantly upregulated in the retina of these mice, while IL-20RA expression in the optic nerve is downregulated following pressure-induced damage. The identification of a mutation in the IL-20RB gene in a
glaucoma pedigree and changes in expression levels of
IL-20 family members in the DBA/2J mouse suggest that disruption of normal
IL-20 signaling in the eye may contribute to degenerative processes associated with
glaucoma.