Methods to measure the biomechanical properties of the cornea are discussed in Chapter 2.

Dawson DG, Ubels JL, Edelahauser HF. Cornea and sclera. In: Kaufman PL, Alm A, eds. Adler’s Physiology of the Eye. 11th ed. New York: Saunders/Elsevier; 2011.

Sclera

The sclera is composed primarily of type I collagen and proteoglycans (decorin, biglycan, and aggrecan). Other components include elastin and glycoproteins such as fibronectin. Fibroblasts lie along collagen bundles. The long posterior ciliary nerves supply the anterior sclera.

Normally a densely white tissue, sclera becomes more translucent when thinning occurs or the water content changes, falling below 40% or rising above 80%. For example, senile scleral plaques are areas of calcium phosphate deposits just anterior to the insertions of the medial and lateral rectus muscles that become dehydrated and reveal the blue color of the underlying uvea.

Nishido T. Cornea and sclera. In: Krachmer JH, Mannis MJ, Holland EJ, eds. Cornea. 3rd ed. Vol 1. Philadelphia: Elsevier/Mosby; 2011:3–24.