What causes pterygium

What is a Pterygium?

A pterygium (pronounced 'tuh-RIJ-ee-um') is a fleshy, triangular growth of tissue that starts on the conjunctiva (the clear membrane covering the white part of the eye) and extends onto the cornea (the clear front surface of the eye). While often referred to as 'surfer's eye' due to its common occurrence in individuals who spend a lot of time in the sun, sea, and wind, it can affect anyone exposed to prolonged environmental irritants.

Causes of Pterygium

The primary and most significant cause of pterygium is prolonged and repeated exposure to ultraviolet (UV) radiation, predominantly from sunlight. The sun's UV rays are believed to damage the cells of the conjunctiva, leading to abnormal growth. This is why pterygia are far more common in sunny climates and among populations with significant outdoor occupational or recreational exposure.

Beyond UV exposure, several other environmental factors can contribute to or exacerbate the development of pterygium:

• Dry Environments: Living in arid or low-humidity regions can lead to chronic dryness of the eye surface. This dryness can irritate the conjunctiva, making it more susceptible to UV damage and abnormal growth.
• Wind Exposure: Constant exposure to wind can dry out the eyes and carry irritants like dust and sand, further contributing to conjunctival irritation.
• Dust and Sand: Working or living in environments with significant amounts of airborne dust or sand can cause chronic physical irritation to the eye's surface.
• Allergens: While not a direct cause, chronic allergic conjunctivitis (inflammation of the conjunctiva due to allergies) might play a role in making the eye more susceptible to other irritants.

Who is at Risk?

Individuals most at risk for developing pterygium include:

• People who live in or spend a lot of time in sunny, windy, and dusty regions.
• Occupational groups such as farmers, sailors, construction workers, and anyone whose work requires extensive time outdoors.
• Recreational enthusiasts like surfers, skiers, and fishermen.
• People with lighter skin and eye color, who may be more sensitive to UV damage.
• Individuals who have had previous eye surgery, although this is less common.

Symptoms of Pterygium

In many cases, a small pterygium may cause no symptoms. However, as it grows, it can lead to:

• Redness and inflammation.
• A feeling of grittiness or a foreign body in the eye.
• Dryness and irritation.
• Blurred vision, especially if the pterygium grows over the pupil and distorts the cornea's shape or interferes with the tear film.
• Discomfort or itching.

Prevention and Management

Preventing pterygium largely involves protecting the eyes from its primary cause: UV radiation. This can be achieved by:

• Wearing sunglasses that offer 100% UV protection, especially wide-brimmed styles that shield the sides.
• Wearing a hat with a brim to further block sunlight.
• Using artificial tears to keep the eyes lubricated, particularly in dry or windy conditions.
• Wearing protective eyewear, such as goggles, when exposed to dusty or windy environments.

If a pterygium develops and causes symptoms or affects vision, treatment options may include lubricating eye drops, steroid eye drops to reduce inflammation, or surgical removal if the growth is significant or impacts vision.