Scleral spur

The scleral spur is an annular structure composed of collagen in the human eye, a protrusion of the sclera into the anterior chamber. It is the origin of the longitudinal fibres of the ciliary muscle and is attached anteriorly to the trabecular meshwork.

Open-angle glaucoma (OAG) and closed-angle glaucoma (CAG) may be treated by muscarinic receptor agonists (e.g., pilocarpine), which cause rapid miosis and contraction of the ciliary muscles, this pulls the scleral spur and results in the trabecular meshwork being stretched and separated. This opens the fluid pathways and facilitates drainage of the aqueous humour into the canal of Schlemm and ultimately decreasing intraocular pressure.

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