Trichiasis is a disorder of structure or function in a human, animal, or plant, especially one that produces specific symptoms or that affects a specific location and is not simply a direct result of physical injury.

What is Trichiasis ?

Trichiasis is an acquired condition characterised by posterior misdirection of previously normal eye lashes. The misdirected lashes may be diffuse involving the entire lid (diffuse trichiasis) or may involve a small segment of it (simple trichiasis). Simple trichiasis is relatively more common as compared to diffuse trichiasis.

Trichiasis is differentiated from pseudotrichiasis which occurs secondary to entropion (inward turning of eyelid). Both these conditions lead to irritation of cornea and may lead to punctate epitheliopathy. Trichiasis may lead to infectious keratitis, pannus formation or even corneal ulceration.

Trichiasis may be associated with conditions like trachoma or severe chronic staphylococcal blepharitis.

Trichiasis Symptoms

  • Patient may present with symptoms like:

    - Irritation of eyes.

    - Foreign body sensation in eye.

    - Redness of eyes.

    - Watering.

    - Eye discharge.

    - Pain in eyes.

    - Increased sensitivity to light.

    - Corneal abrasion.

    - Corneal ulceration.

    - Symblepharon (adhesion of eyelids to the eyeball).

    - Loss of normal eyelid margin structures e.g. madarosis (absence or loss of eye lashes).

    - Dryness of eyes due to keratinisation.

Trichiasis Causes

There are various causes of trichiasis:-

Infectious causes:

- Trachoma.

- Herpes zoster.

Autoimmune:

- Ocular cicatricial pemphigoid.

Inflammatory:

- Stevens-Johnson syndrome

- Vernal keratoconjunctivitis.

- Chronic staphylococcal blepharitis.

Chemical:

- Alkali burns.

- Use of glaucoma eye drops.

Trauma:

- Repair of orbital floor fracture.

- Blepharoplasty (eyelid surgery).

- Repair of ectropion.

- Following enucleation.

Trichiasis Diagnosis


Diagnosis is based on history and clinical examination.

History:

History of following conditions may be elaborated for the diagnosis:-

- Eye infections like trachoma or herpes zoster.

- Trauma or surgery of the lids.

- Chemical or thermal burns.

- Use of glaucoma eye drops.

- Inflammatory conditions like Stevens-Johnson syndrome or chronic blepharitis.

- Ocular cicatricial pemphigoid.

Clinical features:

Clinical examination helps in finding the cause of trichiasis.

Examination may require slit-lamp examination by a qualified eye-specialist.

- Trachoma: Trachoma may cause posterior lamellar (tarsus and conjunctiva) scarring. Scarring causes difficulty in eversion of eyelid.

- Stevens-Johnson syndrome and ocular cicatricial pemphigoid: These conditions lead to symblepharon formation and fornix (junction of eyelid and eyeball conjunctiva) scars.

- Involutional entropion with horizontal lid laxity: Horizontal lid laxity may be tested by snap back test. Examiner pulls lower lid down and observes the lid returning to its original position without allowing patient to blink. Normally, lid returns back quickly without blinking, but in increased laxity, blink may be needed for its return to normal position. The examiner can also pull the lower lid anteriorly away from the globe. In involutional entropion, lid may be pulled away by 6-15mm from the globe, as compared to 2-3mm only in normal lid.

Trichiasis should be differentiated from conditions like:-

- Congenital distichiasis: In congenital distichiasis, there is partial or complete second row of eye lashes growing out of or slightly behind the meibomian gland orifices. Eye lashes in this condition are thinner, shorter and less pigmented than normal cilia (eye lashes).

- Acquired metaplastic eye lashes: Acquired metaplastic eye lashes may occur in late stages of Stevens-Johnson syndrome, trachoma and chemical burns. In this, eye lashes exit near the meibomian gland orifices and are associated with other changes such as keratinisation of the conjunctiva.

- Congenital epiblepharon: Congenital epiblepharon shows an extra horizontal fold of skin which stretches across the lid margin. The eye lashes may be turned upward, particularly medially. These may touch the cornea but they rarely cause discomfort in the eye. In epiblepharon, on pulling the lid down, the lashes turn out and the normal position of lid margin becomes visible.

- Entropion: Entropion causes inversion of eyelid margin and pseudotrichiasis. Eyelash produces irritation to the exposed surface of the eyeball. In congenital entropion, on pulling the lid down, the entire eyelid is pulled away from the eyeball, unlike congenital epiblepharon.

Diagnosis is based on history and clinical examination.

History:

History of following conditions may be elaborated for the diagnosis:-

- Eye infections like trachoma or herpes zoster.

- Trauma or surgery of the lids.

- Chemical or thermal burns.

- Use of glaucoma eye drops.

- Inflammatory conditions like Stevens-Johnson syndrome or chronic blepharitis.

- Ocular cicatricial pemphigoid.

Clinical features:

Clinical examination helps in finding the cause of trichiasis.

Examination may require slit-lamp examination by a qualified eye-specialist.

- Trachoma: Trachoma may cause posterior lamellar (tarsus and conjunctiva) scarring. Scarring causes difficulty in eversion of eyelid.

- Stevens-Johnson syndrome and ocular cicatricial pemphigoid: These conditions lead to symblepharon formation and fornix (junction of eyelid and eyeball conjunctiva) scars.

- Involutional entropion with horizontal lid laxity: Horizontal lid laxity may be tested by snap back test. Examiner pulls lower lid down and observes the lid returning to its original position without allowing patient to blink. Normally, lid returns back quickly without blinking, but in increased laxity, blink may be needed for its return to normal position. The examiner can also pull the lower lid anteriorly away from the globe. In involutional entropion, lid may be pulled away by 6-15mm from the globe, as compared to 2-3mm only in normal lid.

Trichiasis should be differentiated from conditions like:-

- Congenital distichiasis: In congenital distichiasis, there is partial or complete second row of eye lashes growing out of or slightly behind the meibomian gland orifices. Eye lashes in this condition are thinner, shorter and less pigmented than normal cilia (eye lashes).

- Acquired metaplastic eye lashes: Acquired metaplastic eye lashes may occur in late stages of Stevens-Johnson syndrome, trachoma and chemical burns. In this, eye lashes exit near the meibomian gland orifices and are associated with other changes such as keratinisation of the conjunctiva.

- Congenital epiblepharon: Congenital epiblepharon shows an extra horizontal fold of skin which stretches across the lid margin. The eye lashes may be turned upward, particularly medially. These may touch the cornea but they rarely cause discomfort in the eye. In epiblepharon, on pulling the lid down, the lashes turn out and the normal position of lid margin becomes visible.

- Entropion: Entropion causes inversion of eyelid margin and pseudotrichiasis. Eyelash produces irritation to the exposed surface of the eyeball. In congenital entropion, on pulling the lid down, the entire eyelid is pulled away from the eyeball, unlike congenital epiblepharon.