Which statement about pterygium is NOT true?

Which statement about pterygium is NOT true?

• A. It is most commonly caused by UV light exposure
• B. It typically induces ATR astigmatism
• C. It primarily destroys Bowmans' membrane of the cornea
• D. It can be associated with Stocker's line

Answer: (B)

A pterygium is a fibrovascular growth that starts on the bulbar conjunctiva, usually Nasally, and extends onto the cornea. It is strongly linked to UV exposure. As it encroaches toward the central cornea, it mechanically alters the corneal curvature, typically flattening the horizontal meridian. This causes the vertical meridian to become relatively steeper, producing with-the-rule astigmatism rather than against-the-rule (ATR). So the notion that pterygium typically induces ATR astigmatism isn’t consistent with the common pattern seen clinically. Stocker’s line, a pigmented iron line at the leading edge of the pterygium, is a familiar accompanying sign, and Bowman's membrane is disrupted where the tissue invades the corneal surface—both consistent with pterygium pathology. A is true because UV exposure is a major risk factor, and D is true as Stocker’s line can be present. C reflects its invasion and disruption of Bowman's layer, which fits the condition, though the key diagnostic impact here is the astigmatism direction.

A pterygium is a fibrovascular growth that starts on the bulbar conjunctiva, usually Nasally, and extends onto the cornea. It is strongly linked to UV exposure. As it encroaches toward the central cornea, it mechanically alters the corneal curvature, typically flattening the horizontal meridian. This causes the vertical meridian to become relatively steeper, producing with-the-rule astigmatism rather than against-the-rule (ATR). So the notion that pterygium typically induces ATR astigmatism isn’t consistent with the common pattern seen clinically.

Stocker’s line, a pigmented iron line at the leading edge of the pterygium, is a familiar accompanying sign, and Bowman's membrane is disrupted where the tissue invades the corneal surface—both consistent with pterygium pathology. A is true because UV exposure is a major risk factor, and D is true as Stocker’s line can be present. C reflects its invasion and disruption of Bowman's layer, which fits the condition, though the key diagnostic impact here is the astigmatism direction.