Which statement best describes the scleral spur?

Which statement best describes the scleral spur?

• A. A region of circularly oriented collagen bundles that extends from the inner aspect of the sclera
• B. A vascular channel within the sclera
• C. A circular ring around the cornea
• D. A region of circularly oriented collagen bundles that extends from the inner aspect of the sclera

Answer: (D)

The key idea is the structure and location of the scleral spur. It is a thickening of the sclera formed by circularly oriented collagen bundles that extend inward from the inner aspect of the sclera, creating a prominent landmark at the iridocorneal angle and helping define the boundary for the trabecular meshwork and Schlemm’s canal. This description best matches the option describing circularly oriented collagen bundles extending from the inner scleral surface. The other statements refer to different structures—vascular channels within the sclera or a circular ring around the cornea—and do not describe the scleral spur.

The key idea is the structure and location of the scleral spur. It is a thickening of the sclera formed by circularly oriented collagen bundles that extend inward from the inner aspect of the sclera, creating a prominent landmark at the iridocorneal angle and helping define the boundary for the trabecular meshwork and Schlemm’s canal. This description best matches the option describing circularly oriented collagen bundles extending from the inner scleral surface. The other statements refer to different structures—vascular channels within the sclera or a circular ring around the cornea—and do not describe the scleral spur.