Pterygium

What is Pterygium?

A pterygium (pronounced ter-IJ-ee-um) is a benign, wedge-shaped growth of thickened conjunctival tissue that extends from the white of the eye (sclera) onto the clear cornea. It is most common in people who have spent significant time outdoors in sunny, dusty, or windy environments — UV light is the primary driver. A pterygium may remain stable for years, or it may slowly grow towards the pupil, threatening vision. Surgical removal is curative, though recurrence is possible.

Symptoms

• A visible pink or reddish fleshy growth on the white of the eye, usually on the nasal side
• Redness, irritation or a gritty sensation
• Blurred vision if the growth encroaches on the cornea
• Induced astigmatism as the growth distorts the corneal surface
• Dry eye symptoms

Causes

• Chronic UV light exposure — the dominant risk factor
• Wind, dust and low humidity — occupational and environmental exposure
• Genetic susceptibility

Diagnosis

Slit-lamp examination. Corneal topography is useful to quantify the degree of astigmatism induced by the pterygium and to guide timing of surgery.

Treatment

Lubricating eye drops and UV-protective sunglasses manage mild symptoms. Surgical excision is recommended when the pterygium threatens the visual axis, causes significant astigmatism or cosmetic concern, or symptoms are poorly controlled. Conjunctival autografting (taking tissue from under the upper eyelid to cover the excision site) reduces recurrence rates to under 5%.