PTERYGIUM

'Pterygium' usually refers to a benign growth of the conjunctiva. Alternately, it refers to any winglike triangular membrane occurring in the neck, eyelids, knees, elbows, ankles or digits (J Pediatr Orthop B 2004, 13:197-201). An example is popliteal pterygium syndrome, which affects the legs. The term comes from the Greek word ''pterygion'' meaning "wing".
When associated with the conjunctiva, a pterygium commonly grows from the nasal side of the sclera. It is associated with, and thought to be caused by ultraviolet-light exposure (e.g. sunlight), low humidity, and dust. The predominance of pterygia on the nasal side is possibly a result of the sun's rays passing laterally through the cornea where it undergoes refraction and becomes focused on the limbic area. Sunlight passes unobstructed from the lateral side of the eye, focusing on the medial limbus after passing through the cornea. On the contralateral side, however, the shadow of the nose medially reduces the intensity of sunlight focused on the lateral/temporal limbus. Pterygium as an early indicator of ultraviolet insolation: a hypothesis, , MT, Coroneo, Br J Ophthalmol,

Contents

Pathology

Treatment

See also

External links

References

Pathology

Pterygium in the conjunctiva is characterized by elastotic degeneration of collagen and fibrovascular proliferation.
It has an advancing portion called the head of the pterygium, which is connected to the main body of the pterygium by the neck. Sometimes a line of iron deposition can be seen adjacent to the head of the pterygium called ''Stocker's line''. The location of the line can give an indication of the pattern of growth. As it is a benign growth, it requires no treatment unless it grows to such an extent that it covers the pupil, obstructing vision. Some patients may also choose surgery if the growth becomes too unsightly. The exact cause is unknown, but it is associated with excessive exposure to wind, sun, or sand. Wearing protective sunglasses with side shields and/or wide brimmed hats and using artificial tears throughout the day may help prevent their formation or stop further growth.
Occasionally it is found as an incidental finding in middle aged patients who spend a lot of time in the sun.

Treatment

While patients can be symptomatically treated w/ artificial tears, no reliable medical treatment exists to reduce or even prevent pterygium progression. Definitive treatment is achieved only by surgical removal. Long term follow up is required as pterygium may recur even after complete surgical correction.

See also

★ List of eye diseases and disorders

★ Pinguecula

External links

★ Facts About the Cornea and Corneal Disease The National Eye Institute (NEI)

References