Entropion

Entropion is inward turning of the eyelid margin so that lashes and keratinised skin rub against the cornea and conjunctiva. It involves the lower lid in most cases, and chronic irritation can lead to keratopathy, corneal ulceration, and scarring.

• Types:
  • Involutional (the commonest): horizontal lid laxity from stretching of the canthal tendons and tarsus, dehiscence or disinsertion of the lower lid retractors, and override of the preseptal orbicularis over the pretarsal orbicularis. Affects older adults.
  • Cicatricial: shortening of the posterior lamella from scarring due to trachoma, chemical injury, ocular cicatricial pemphigoid, Stevens-Johnson syndrome, herpes zoster, or previous surgery.
  • Acute spastic: orbicularis spasm after ocular irritation or surgery in an eye with underlying laxity.
  • Congenital: rare, caused by tarsal kink or retractor dysgenesis; epiblepharon (a skin and orbicularis fold pushing lashes inward) is a distinct condition in Asian children, mostly harmless.
• Prevalence rises with age; recurrent irritation causes epiphora, secondary infection, and in untreated cases visual loss from scarring.

• Foreign body sensation, tearing, redness, photophobia, and mucous discharge; vision may be blurred by surface disease.
• The lid margin rolls inward, with lashes touching the cornea; the lid may appear normal in the primary position and roll in with forced closure or downgaze.
• Punctate epithelial erosions of the inferior cornea, corneal ulceration, vascularisation, and scarring in prolonged cases.
• Cicatricial: shortened posterior lamella, symblepharon, keratinised lid margin, trichiasis, and conjunctival scarring.
• Acute spastic: sudden onset after surgery or inflammation.

• Clinical examination of the lid in primary gaze, on blinking, and with forced closure; look for the lid margin position and the lashes' contact with the globe.
• Tests for involutional entropion: snap back test (the lid returns slowly or only after blinking when pulled from the globe, indicating laxity), distraction test (a lid that can be pulled more than 6 mm from the globe indicates horizontal laxity), medial and lateral canthal tendon laxity, and examination of the lower lid retractor (the lower lid crease height and reduced lid excursion on downgaze).
• Fluorescein staining of the cornea; slit lamp assessment for trichiasis and conjunctival scarring.
• For cicatricial disease: conjunctival biopsy and direct immunofluorescence (pemphigoid), and evaluation for trachoma and drug causes.
• Exclude epiblepharon (in children, no tarsal inversion) and lid margin lesions.

• Temporary measures while awaiting surgery: preservative free lubricating drops four to six times daily and ointment at night, taping the lower lid down (skin tape from the lid margin to the cheek), and a soft bandage contact lens.
• Botulinum toxin type A: 2.5 to 5 units injected into the pretarsal orbicularis of the lower lid gives 3 to 4 months of relief and is useful for acute spastic entropion or in patients unfit for surgery.
• Everting (Quickert) sutures: three double armed 4-0 absorbable or silk sutures passed from the inferior fornix to the skin below the lashes and tied over a bolster, creating scarring that holds the lid out; effect lasts for months to years; used as a temporary or definitive measure in frail patients.
• Surgery for involutional entropion (definitive):
  • Lateral tarsal strip to tighten the horizontal laxity, combined with plication or reattachment of the lower lid retractors to the tarsus (the retractor reinsertion), with removal of excess orbicularis if override is present. Success exceeds 90 percent.
  • The Wies procedure (a full thickness horizontal blepharotomy with eversion sutures) for mild cases.
• Cicatricial entropion: posterior lamella lengthening with a hard palate or buccal mucous membrane graft, tarsal fracture (transverse tarsotomy) with margin rotation, or lid margin splitting for mild disease. Treat the underlying disease (trachoma with azithromycin, pemphigoid with immunosuppression).
• Congenital entropion or epiblepharon: observation (most resolve), lubricants, and surgical correction (Hotz procedure or excision of skin and muscle fold) if persistent corneal symptoms.
• Follow up after surgery at 1 week and 1 to 3 months for recurrence (about 10 to 20 percent for involutional disease); sutures are removed at 1 to 2 weeks.
• Complications: recurrence, overcorrection to ectropion, lid margin notching, and infection.