Irritation, foreign-body sensation, tearing, redness, and photophobia.

Critical

Misdirected eyelashes rubbing against the globe.

Other

Conjunctival injection; SPK; corneal epithelial defect, infiltrate, or scarring.

• Entropion: Inward turning of eyelid pushing normal lashes onto the cornea. See 6.3, Entropion.

• Epiblepharon: Congenital or familial condition in which redundant lower eyelid anterior lamella redirects lashes into a vertical position, where they may contact the globe. Most common in Asian individuals, especially children.

• Distichiasis: An aberrant second row of lashes arising from meibomian gland orifices. Most commonly acquired in the setting of trauma or chronic inflammation (e.g., blepharitis, mucous membrane pemphigoid). Congenital distichiasis is a rare, sometimes hereditary, condition in which the meibomian glands are replaced by an extra row of eyelashes.

• Idiopathic.

• Chronic blepharitis: Inflamed eyelid margin. See 5.8, Blepharitis/Meibomitis.

• Cicatricial: Eyelid scarring from trauma, surgery, mucous membrane pemphigoid (see 5.10, Mucous Membrane Pemphigoid [Ocular Cicatricial Pemphigoid]), herpes zoster ophthalmicus (see 4.17, Herpes Zoster Ophthalmicus/Varicella Zoster Virus), trachoma, Stevens–Johnson syndrome, chemical and thermal burns, medications, and others.

• Medication-induced: Systemic and topical (e.g., prostaglandin analogs).

• Malignancy: Some cases of malignancy causing margin distortion or metaplasia may lead to focal trichiasis. See 6.8 Malignant Tumors of the Eyelid.

1. History: Recurrent episodes? Prior severe systemic illness or allergic reaction? Prior facial trauma or surgery?

2. Slit-lamp examination: Evert the eyelids and inspect the palpebral conjunctiva for scarring and symblepharon. Assess eyelid position for inward rotation statically and dynamically. Check the cornea for epithelial defects, infiltrates, and scarring.

1. Remove the misdirected lashes.

   • A few misdirected lashes: Perform epilation/removal at the slit lamp with fine forceps. Recurrence is common without follicular destruction.

   • Diffuse, severe, or recurrent trichiasis: Definitive therapy usually requires electrolysis, cryotherapy, radiofrequency epilation, argon laser, or eyelid surgery.

2. Treat SPK with antibiotic ointment (e.g., erythromycin or bacitracin b.i.d. to q.i.d.).

3. Treat any underlying blepharitis. See 5.8, Blepharitis/Meibomitis.

4. Address eyelid malposition if present. See 6.3, Entropion.

As needed based on symptom severity and corneal integrity. Closer follow-up is needed if there is evidence of SPK or corneal epithelial defect.