What is a scleral spur?

• A. Protrusion of the sclera into the anterior chamber; marks the posterior border of the trabecular meshwork; point of attachment of the ciliary body; termination of most iris processes
• B. A fold in the iris
• C. A nerve fiber in the retina
• D. The boundary between cornea and sclera

Answer: (A)

The scleral spur is a small projection of the sclera that bulges into the anterior chamber at the angle. It serves as a key architectural landmark: it marks the posterior border of the trabecular meshwork, providing the boundary that defines where the meshwork ends. It also acts as an anchor point for the ciliary body and related structures, helping to stabilize the angle region. The iris processes commonly terminate near this area, tying the iris to the ciliary/scleral structures around the spur.

Other descriptions don’t fit because they refer to different structures: a fold in the iris is not the scleral spur; a nerve fiber in the retina pertains to the retinal nerve fiber layer; and the boundary between the cornea and sclera is the limbus.