What is likely indicated by a triangular thickening of the conjunctiva encroaching on the cornea?

A triangular thickening of the conjunctiva that encroaches on the cornea is indicative of a pterygium. This condition typically presents as a fleshy growth that originates on the conjunctiva and extends onto the cornea, usually on the nasal side, and can be related to chronic exposure to wind, sunlight, and dust.

Pterygium is characterized by its triangular shape, and it can potentially cause irritation, redness, and even vision changes if it grows large enough to cover the pupil. This growth occurs due to a combination of environmental factors and may affect individuals who spend significant time outdoors.

In contrast, a pinguecula is a yellowish bump that forms on the conjunctiva but does not grow onto the cornea in a triangular shape, and corneal arcus refers to a gray or white arc at the edge of the cornea typically associated with aging or lipid disorders. A chalazion is a lump that forms in the eyelid due to a blocked gland and does not involve the conjunctiva or cornea directly.

Recognizing the distinct characteristics of these conditions is crucial for proper diagnosis and treatment.