pinguecula

**Definition:** Degenerative, yellow-white, triangular or nodular thickening of the bulbar conjunctiva near the limbus, most often on the nasal side within the interpalpebral fissure.

**Pathophysiology:** Chronic actinic (UV) damage, along with wind and dust, causes elastotic (elastoid) degeneration of the substantia propria. Collagen is altered, with hyaline and elastotic deposits. Histology shows basophilic degeneration of collagen that stains with elastin stains. The epithelium may be thickened, thinned, or calcified. Fibroblast activity is not the same as the invasive neovascular fibrovascular growth of pterygium.

**Risk factors:** Age (middle-aged and older), outdoor occupations (farmers, fishermen, welders), sun exposure at low latitudes, and dry or dusty environments. Prevalence rises with age.

**Clinical features:** - Usually asymptomatic and found incidentally. - Cosmetic concerns, foreign body sensation, or dry eye symptoms can occur. - Can become inflamed (pingueculitis), causing redness, irritation, and tearing. - Rarely, it is associated with localized tear film instability and dellen formation (corneal thinning next to an elevated lesion).

**Pinguecula vs. pterygium (high-yield):** - Pinguecula: yellowish, does not cross the limbus, no corneal involvement, no astigmatism or visual loss, rarely needs surgery. - Pterygium: wing-shaped fibrovascular growth that crosses the limbus onto the cornea. It can cause induced astigmatism and visual obstruction, and it is more likely to recur after excision. A pinguecula can progress to a pterygium.

**Differential diagnosis:** Pterygium, conjunctival intraepithelial neoplasia or squamous cell carcinoma (OSSN), conjunctival nevus or melanoma, episcleritis or scleritis (for pingueculitis), and Bitot spots (vitamin A deficiency; foamy, triangular, temporal).

**Management:** - Reassurance and observation. - Lubricating eye drops. - UV-protective sunglasses and a brimmed hat. - Short course of topical NSAIDs or mild topical steroids for pingueculitis. - Surgical excision is rarely indicated (cosmesis, persistent inflammation, contact lens intolerance, or suspicion of neoplasia). Recurrence is possible.

**Boards pearl:** A yellow, nasal, perilimbal conjunctival bump in an outdoor worker that does not invade the cornea is a pinguecula. A growth that crosses onto the cornea is a pterygium.