Matted Eye: Common Causes
A matted eye is most commonly caused by bacterial conjunctivitis or blepharitis, both of which produce discharge that crusts and causes the eyelids to stick together, particularly upon waking. 1, 2, 3
Primary Causes
Bacterial Conjunctivitis
The hallmark feature distinguishing bacterial from other causes is mattering and adherence of the eyelids on waking 3. This occurs because:
- Bacterial infection produces purulent or mucopurulent discharge that accumulates overnight
- The discharge dries and forms crusts that glue the lids together
- Most cases are self-limiting (1-2 weeks) but topical antibiotics shorten duration 3
- Lack of itching and no history of prior conjunctivitis strongly suggest bacterial etiology 3
Staphylococcal Blepharitis
This anterior eyelid inflammation causes matted lids through 1:
- Scaling, crusting, and collarette formation at the base of eyelashes
- Chronic inflammation with acute flares
- Both Staphylococcus aureus and coagulase-negative staphylococcus play roles
- Greasy scaling may indicate seborrheic variant
Secondary Causes to Consider
Meibomian Gland Dysfunction (MGD)
- Posterior blepharitis affecting oil glands 1
- Causes altered tear film and mucoid discharge
- Often coexists with anterior blepharitis
- Can contribute to "sticky eyelid syndrome" in severe cases 4
Viral Conjunctivitis
- Most common overall cause of infectious conjunctivitis 3
- Produces watery discharge (less matting than bacterial)
- Self-limited, no treatment needed
- Variable presentation makes it harder to distinguish clinically
Allergic Conjunctivitis
- Itching is the most consistent sign 3
- Watery or mild mucous discharge
- Less likely to cause significant matting
- Bilateral presentation typical 2
Clinical Approach
Look for these distinguishing features:
- Purulent discharge + lid adherence on waking = bacterial conjunctivitis 3
- Crusting at lash base + chronic course = staphylococcal blepharitis 1
- Itching predominant = allergic cause 3
- Watery discharge + viral symptoms = viral conjunctivitis 3
Important Caveats
- Blepharitis and dry eye are the most frequent causes of conjunctival inflammation overall 2, so always examine the eyelid margins
- Multiple conditions often coexist (blepharitis + MGD + dry eye) 2
- In children, blepharoconjunctivitis can lead to serious complications including vision loss 1
- Gonococcal or chlamydial conjunctivitis requires systemic antibiotics, not just topical therapy 2, 3