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Describe entropion, ectropion and trichiasis with their management.

Ophthalmology · 3rd Professional

Entropion

Entropion is inward turning of the lid margin, so that the lashes and keratinised skin rub against the cornea.
It is sight-threatening, because the constant abrasion causes epithelial breakdown, ulceration and scarring.

Type	Mechanism and features
Involutional (senile)	The commonest, affecting the lower lid of the elderly. Three age changes combine: horizontal lid laxity (of the canthal tendons and tarsus); disinsertion of the lower lid retractors.
Cicatricial	Scarring and contracture of the posterior lamella pulls the margin in. Affects either lid. Causes: trachoma (much the commonest worldwide and historically in India), stevens-johnson syndrome, ocular cicatricial pemphigoid, chemical burns, trauma and previous surgery
Congenital	True congenital entropion is rare and results from tarsal maldevelopment; it has to be told apart from epiblepharon
Spastic (acute)	Sustained orbicularis spasm from ocular irritation, classically after surgery or with blepharospasm; it resolves when the irritation settles, and may be held temporarily with tape or botulinum toxin

Epiblepharon has to be told apart from congenital entropion, and is far commoner: an extra horizontal fold of skin and orbicularis near the lid margin, especially of the lower lid in ASIAN children.

Ectropion

Ectropion is outward turning of the lid margin away from the globe.
It causes epiphora (because the punctum no longer contacts the tear lake), exposure keratopathy and keratinisation of the exposed conjunctiva.

Type	Mechanism and treatment
Involutional	The commonest; horizontal laxity of the lower lid and canthal tendons in the elderly. Treated by horizontal shortening — a lateral tarsal strip, with a medial spindle or medial canthal tendon plication where the punctum is everted
Cicatricial	Shortage of the anterior lamella, from burns, trauma, chronic sun damage, skin disease or excessive skin excision at blepharoplasty. Treated by lengthening the anterior lamella with a full-thickness skin graft (from the upper lid, postauricular or supraclavicular skin) or a local flap
Paralytic	Facial nerve palsy, with orbicularis weakness. Managed with intensive lubrication and taping while recovery is awaited; then lid tightening, a medial canthoplasty, and a gold or platinum weight in the upper lid to restore closure
Mechanical	A lid or orbital tumour, oedema or a large chalazion pulling the lid outward; treat the cause
Congenital	Rare; associated with blepharophimosis syndrome and with ichthyosis

Medial ectropion with a visible everted punctum is a common and easily missed cause of a watering eye, and is corrected by a medial spindle (Lazy-T) procedure

Trichiasis and Related Disorders

Trichiasis is misdirection of lashes from a normally positioned lid margin — which distinguishes it from entropion, in which the whole margin is turned in. The two frequently coexist, and the distinction matters because the treatments differ
Causes — trachoma above all; chronic blepharitis; Stevens-Johnson syndrome and pemphigoid; trauma and burns; and previous lid surgery
Treatment depends on the number of lashes: epilation for a few lashes gives relief for only 4 to 6 weeks and the regrowing lash is stubbier and more abrasive, so it is a temporising measure only; electrolysis for a few scattered lashes; cryotherapy or argon laser ablation for localised segments; and surgery — lid split with cryotherapy, or bilamellar tarsal rotation — for diffuse trichiasis.
Distichiasis — an accessory row of lashes emerging from the meibomian gland orifices, arising from metaplasia of those glands. It may be congenital (dominant, associated with lymphoedema-distichiasis syndrome) or acquired after cicatrising disease
Madarosis is loss of lashes — from chronic blepharitis, burns, trichotillomania, and systemic disease including leprosy (with loss of the lateral eyebrow, madarosis superciliaris), hypothyroidism, alopecia areata and syphilis
Poliosis is whitening of the lashes — in chronic blepharitis, VOGT-koyanagi-HARADA disease, sympathetic ophthalmitis, Waardenburg syndrome and vitiligo
Lagophthalmos — failure of complete lid closure, causing exposure keratopathy of the inferior third. From facial palsy, proptosis, cicatricial lid shortening, nocturnal lagophthalmos and after over-correction of ptosis. Managed with lubricants, ointment and taping at night, a moisture chamber, botulinum-induced ptosis, a gold weight and tarsorrhaphy

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