What is the most likely diagnosis for a patient with a triangular growth on the conjunctiva?

A triangular growth on the conjunctiva is most commonly indicative of a pterygium. This benign ocular condition typically appears as a fleshy, triangular-shaped growth that extends from the conjunctiva onto the cornea, often as a result of prolonged exposure to ultraviolet light, wind, dust, and environmental factors.

The development of a pterygium is associated with irritation and inflammation, and it can potentially impair vision if it grows significantly, obstructing the visual axis. Management may include observation for asymptomatic cases, but more advanced cases or those causing significant symptoms may require surgical intervention.

Understanding the differentiation from other conditions is important. A pingueculum, for example, is a yellowish, raised lesion that is located on the conjunctiva but does not extend onto the cornea and is not typically triangular in shape. A chalazion presents as a localized swelling in the eyelid it is a blocked oil gland, and a hordeolum, or stye, is an acute infection of the eyelid margin. Neither of these conditions involves growth on the conjunctiva itself nor resembles the triangular shape characteristic of a pterygium.