The scleral spur and scleral roll.
The scleral spur and scleral roll together form a fibrous hoop which may be detached from adjacent structures as a unit. Tensile tests of the spur-roll resemble reported data on sclera. It is proposed that the circular structure of the spur-roll prevents action of the meridional portion of the ciliary muscle on the trabecular meshwork from collapsing the canal of Schlemm.
D000368:Aged; D006801:Humans; D008875:Middle Aged; D012590:Sclera / Q000033:anatomy & histology* / Q000502:physiology; D013718:Tensile Strength