Conjunctival Concretions: Causes
Conjunctival concretions are primarily caused by chronic conjunctival inflammation, resulting in the accumulation of cellular degeneration products—specifically phospholipids, elastin, and membranous debris—in the subepithelial space.
Pathophysiology
The underlying mechanism involves chronic inflammatory processes that lead to cellular breakdown and debris accumulation 1:
- Composition: Concretions consist of finely granular material and membranous debris composed of phospholipids and elastin, representing products of cellular degeneration rather than calcium deposits 1
- Location: These deposits accumulate in the conjunctival subepithelium, typically appearing as yellow spots in the tarsal conjunctiva 1
- Important caveat: The term "lithiasis" is misleading since calcium and phosphate are absent from these deposits 1
Primary Etiologic Factors
Chronic Inflammatory Conditions
The most common predisposing factor is chronic conjunctivitis of any etiology 1:
- Atopic keratoconjunctivitis: Strongly associated with concretion formation due to prolonged inflammation 1
- Trachomatous degeneration: Post-trachomatous changes create an environment conducive to concretion development 1
- Chronic blepharitis and meibomian gland dysfunction: Present in 30.3% of patients with conjunctival concretions 2
Age-Related Factors
- Aging conjunctiva: The most important risk factor, with concretions appearing as early as age 20 but peaking between 30-80 years 2
- Prevalence: Found in 39.6% of random outpatient populations, though only 6% are symptomatic 2
Medication-Induced Inflammation
Chronic topical medication use can trigger the inflammatory cascade leading to concretions 3:
- Glaucoma medications (particularly pilocarpine and timolol) 3
- Topical NSAIDs, antibiotics, and antivirals 3
- Preservatives in eye medications: Most problematic with multiple medications or frequent dosing 3
Contact Lens-Related Inflammation
- Mechanical irritation and chronic hypoxia from contact lens wear can precipitate chronic inflammation leading to concretion formation 3
- Risk factors: Soft contact lenses, infrequent replacement, prolonged wearing time, poor hygiene 3
Other Inflammatory Conditions
- Conjunctival chalasis: Redundant conjunctiva with chronic irritation may be associated 3
- Floppy eyelid syndrome: Chronic ocular irritation from nocturnal eyelid malposition 3
Clinical Pearls
- Most concretions are asymptomatic: Only 6% of patients with concretions experience foreign body sensation 2
- Bilateral and superficial: Superficial deposits (85.8%) are more common than deep ones, and hard deposits (79.8%) predominate over gelatinous types 2
- No laterality preference: Equal distribution between upper and lower lids, and right versus left eyes 2
Common Pitfall
Do not confuse conjunctival concretions with calcium deposits or assume they require treatment unless symptomatic—the vast majority are incidental findings related to age and prior inflammation that require no intervention 1, 2.