Causes
Eye rosacea
The exact cause of ocular rosacea remains unknown, but several factors are thought to contribute:
- Genetic Predisposition: A hereditary component is suggested, as ocular rosacea often runs in families.
- Microbial Factors: Demodex mites and bacterial involvement are significant contributors. Bacterial lipases may release toxic free fatty acids, causing inflammation. Additionally, the pro-inflammatory cytokine interleukin-1 alpha (IL-1α) increases metallomatrix protein-9 (MMP-9) in the tear fluid, leading to tissue damage.
- Environmental Triggers: Factors such as sunlight, wind, extreme temperatures, spicy foods, alcohol, stress, and strenuous exercise can exacerbate symptoms.
- Immunological Factors: An overactive immune response may contribute to inflammation.
- Meibomian Gland Dysfunction: Blocked glands in the eyelids can alter the composition of the tear film, leading to dry eyes and irritation.
- Helicobacter Pylori: Some studies suggest a link between rosacea and Helicobacter pylori bacteria, known to cause gastrointestinal infections.
Clinical Signs
Eyelid and Conjunctiva: Anterior blepharitis (inflammation of the eyelid margin), posterior blepharitis (meibomian gland dysfunction), conjunctival hyperemia (redness), and loss or misdirection of eyelashes.
- Cornea: Keratitis (inflammation), corneal ulcers, pannus formation (vascular fibrous tissue), and phlyctenules (allergic corneal nodules) can occur in severe cases.
- Iris and Sclera: Rarely, inflammation can affect deeper structures such as the iris (iritis) and sclera (episcleritis, scleritis).
