Pinguecula

Definition

Pathophysiology

• Chronic UV light exposure - the primary trigger
• Chronic wind, dust, and environmental irritation
• More prevalent in individuals from equatorial regions (higher UV index)

Epidemiology

• Very common, especially in sunny or dusty climates
• More frequent in people living near the equator
• Associated with outdoor occupations and prolonged sun exposure
• Can occur at any age but more common in middle-aged and older adults

Symptoms

• Irritation and foreign body sensation
• Redness (especially when inflamed - "pingueculitis")
• Dryness and tearing
• Cosmetic concern
• Rarely, decreased vision (vision loss is not typical unless a delle forms or it progresses to pterygium)

Signs

• Yellow-white, flat or slightly elevated conjunctival lesion
• Located in the interpalpebral fissure, usually at the 3-o'clock or 9-o'clock perilimbal position (nasal side more commonly)
• Does NOT involve the cornea (this distinguishes it from pterygium)
• May be highly vascularized and injected when inflamed
• May be associated with superficial punctate keratitis (SPK)
• A delle (localized corneal thinning adjacent to the lesion, due to drying) may be present

Relationship to Pterygium

Differential Diagnosis

• Conjunctival intraepithelial neoplasia (CIN): Papillomatous, jelly-like, velvety or leukoplakic mass - may not follow the typical 3/9-o'clock pattern
• Limbal dermoid: Congenital rounded white lesion, usually inferotemporal
• Pseudopterygium: Conjunctival tissue adherent to peripheral cornea after prior trauma or surgery - associated with corneal thinning
• Pannus: Blood vessels growing into cornea (without a raised lesion); associated with contact lens use, blepharitis, trachoma
• Peripheral hypertrophic subepithelial corneal degeneration: Bilateral, mostly in Caucasian women, elevated subepithelial opacities
• Sclerokeratitis: Associated with scleritis
• Conjunctival squamous cell carcinoma: Particularly in older Caucasian patients - new growths should be referred for specialist workup

Workup

• Slit lamp examination is the key diagnostic tool
  • Evaluate the adjacent corneal integrity and thickness
  • Assess for corneal astigmatism (often irregular, but may be with-the-rule)
• No laboratory workup is routinely needed
• Biopsy is warranted if the lesion appears atypical or if CIN cannot be excluded

Management

1. Prevention / General Measures

• UV-protective sunglasses (wraparound style preferred)
• Protective goggles in dusty or windy environments

2. Lubrication

• Preservative-free artificial tears, 4-8 times per day - the first-line symptomatic treatment

3. Inflamed Pinguecula (Pingueculitis)

• Mild: Artificial tears QID
• Moderate to severe:
  • Topical mild corticosteroid (e.g., fluorometholone 0.1%, loteprednol 0.2%-0.5% QID)
  • Topical NSAID (e.g., ketorolac 0.4%-0.5% QID)
  • Topical antihistamine ± mast cell stabilizer (e.g., bepotastine, ketotifen, olopatadine)

4. Delle (adjacent corneal thinning)

• Artificial tear ointment every 2 hours

5. Surgical Removal

• Excessive irritation not relieved by medical treatment
• Interfering with contact lens wear
• Cosmetic concerns are significant
• Pre-operative preparation before cataract or refractive surgery

Note: Surgical excision with conjunctival autograft or amniotic membrane graft reduces recurrence. Intraoperative mitomycin C (antimetabolite) is typically reserved for recurrent cases, as it carries a risk of corneoscleral thinning or necrosis.

Follow-Up

• Asymptomatic, stable pinguecula: Can be reviewed every 1-2 years
• If treated with topical steroids: recheck after a few weeks to monitor inflammation and intraocular pressure (IOP); taper and discontinue steroid once inflammation has resolved

• Goldman-Cecil Medicine (International Edition, 2-volume set), Section on Pinguecula and Pterygium
• The Wills Eye Manual - Office and Emergency Room Diagnosis and Treatment of Eye Disease, Section 4.9
• Rosen's Emergency Medicine: Concepts and Clinical Practice, Chapter 57