What disease is caused by an eye mite? - briefly
The eye mite Demodex causes ocular demodicosis, commonly manifested as chronic blepharitis. This infestation leads to inflammation of the eyelid margins and irritation of the ocular surface.
What disease is caused by an eye mite? - in detail
The ocular condition produced by a microscopic mite inhabiting the eyelash follicles and sebaceous glands is commonly identified as Demodex‑induced blepharitis. Two species, Demodex folliculorum and Demodex brevis, colonize the skin and eyelid margins; their presence in the eye region triggers inflammation and dysfunction of the lid margin.
Clinical presentation includes:
- Redness and swelling of the eyelid edges
- Crusting or scaling at the base of lashes
- Irritation, burning, or foreign‑body sensation
- Excessive tearing or dry‑eye symptoms
- Visible cylindrical debris (cylindrical dandruff) at the base of lashes
- Occasionally, loss of eyelashes (madarosis) in severe cases
Diagnosis relies on direct microscopic examination of epilated eyelashes. A sample of several lashes is placed on a slide with a drop of saline, covered with a coverslip, and examined at 40×–100× magnification. The detection of more than three mites per lash, or a density exceeding 0.5 mites per follicle, confirms infestation. Additional techniques such as in‑vivo confocal microscopy can visualize mites without removal of lashes.
Therapeutic management focuses on eradicating the mite population and reducing inflammatory response. Effective measures include:
- Topical acaricidal agents – tea‑tree oil‑based ointments (5 % concentration) applied to the lid margin twice daily for 4–6 weeks.
- Prescription medications – ivermectin 1 % cream or oral ivermectin (200 µg/kg) administered as a single dose, followed by repeat dosing if necessary.
- Lid hygiene – warm compresses combined with gentle lid scrubs using diluted hypochlorous acid or commercial lid‑cleaning solutions.
- Adjunctive anti‑inflammatory therapy – low‑dose topical corticosteroids or cyclosporine eye drops for severe inflammation.
Preventive recommendations involve regular lid cleaning, avoidance of oily cosmetics, and monitoring for recurrence, as Demodex populations can re‑establish within weeks after treatment cessation. Epidemiological data show higher prevalence in individuals over 60 years, immunocompromised patients, and those with rosacea or chronic dry‑eye disease.
Complications of untreated infestation may progress to chronic meibomian gland dysfunction, corneal epithelial defects, or secondary bacterial keratitis, highlighting the necessity of prompt identification and targeted therapy.