What is an ocular mite in humans, what are the symptoms? - briefly
Ocular mites are microscopic Demodex parasites that colonize the eyelashes and associated glands of the eye. Infestation produces itching, redness, a gritty sensation, crusty lid margins, and occasionally blurred vision.
What is an ocular mite in humans, what are the symptoms? - in detail
Ocular mites are microscopic arthropods, primarily Demodex folliculorum and Demodex brevis, that inhabit the hair follicles and sebaceous glands of the eyelids. They feed on cellular debris and secretions, completing a life cycle of roughly two weeks. Colonization is usually asymptomatic, but overpopulation can provoke ocular surface disease.
The clinical picture of mite‑related eye involvement includes:
- Redness of the lid margin and conjunctiva, often described as blepharitis.
- Irritation or burning sensation, sometimes accompanied by foreign‑body sensation.
- Excessive tearing or dry‑eye symptoms due to disruption of the tear film.
- Crusting or scaling at the base of the eyelashes; lashes may appear frayed or broken.
- Itching of the eyelid skin, which can lead to secondary bacterial infection if scratched.
- Occasional blurred vision caused by inflammatory debris on the ocular surface.
Diagnosis relies on microscopic examination of epilated eyelashes or lid margin scrapings, revealing characteristic elongated, cigar‑shaped mites. In vivo confocal microscopy can also detect live organisms within follicles.
Management focuses on reducing mite density and controlling inflammation:
- Lid hygiene: warm compresses followed by gentle scrubbing with a diluted tea‑tree oil or commercial lid‑cleaning solution.
- Topical acaricidal agents: ivermectin 1% cream applied to the lid margin, or tea‑tree oil preparations at low concentration.
- Anti‑inflammatory therapy: short courses of topical corticosteroids or cyclosporine A to mitigate ocular surface inflammation.
- Oral ivermectin for severe cases, administered under medical supervision.
Regular follow‑up is essential to confirm eradication, typically demonstrated by negative microscopy after treatment. Persistent symptoms may indicate secondary bacterial overgrowth, requiring appropriate antimicrobial therapy.