Sclera MCQs

The sclera is the white outer coating of the eye. It is tough, fibrous tissue that extends from the cornea(the clear front section of the eye) to the optic nerve at the back of the eye. The sclera gives the eyeball its white color. Reference: Parson 22/e, Pg: 67.

The sclera proper, also known as the scleral stroma, is also called the substantia propria. Ultrasructurally, sclera is composed of: Collagen bundles Elastic fibers Fibroblasts Ground substances These components are responsible for its non-transparent nature. The ground substances consist of proteoglycans and glycoproteins. The collagen bundles in the sclera vary in size and are irregularly arranged, which is why the sclera is not transparent like the cornea. These variations in scleral collagen fibers are more pronounced in the mid-sclera, where the diameter of the fibers ranges from 50 to 400 nm. Reference: Parson 22/e, Pg: 45.

RA is the most commonly associated with scleritis, which is an inflammation of the sclera characterized by vasodilation of the superficial and deep episcleral vessels. Occasionally, scleritis may present before the onset of joint symptoms in the RA patient. It may also occur as a manifestation of systemic vasculitis. However, The most common eye-related symptom of rheumatoid arthritis is dryness. Reference: parson's 22/e section II chapter 16 diseases of the sclera. Pg 228.