Ectropion is an abnormal eversion (outward turning) of the eyelid margin away from globe. Primarily, it involves lower eye lid but upper lid eversion may occur in Floppy eyelid syndrome. Ectropion produces symptoms due to ocular (pertaining to eye) exposure and inadequate lubrication of eyeball. It may cause epiphora, chronic conjunctivitis, conjunctival hypertrophy, exposure keratopathy or even visual loss.
Ectropion may be of following types:-
Mechanical ectropion may occur by displacement of lower eye lid margin by a tumour.
Symptoms are due to irritation of anterior ocular surface, being produced by outward turning of eyelid margin, thereby resulting in exposure of eyeball.
Patient may present with:-
– Lid deformity.
– Foreign body sensation in eye.
– Redness of eyes.
– Tearing/ watering of eyes.
– Eye discharge.
– Pain in eyes.
– Photophobia (intolerance) to light.
– Corneal abrasion.
– Corneal ulceration.
– Dryness of eyes due to keratinisation.
Causes vary according to the type of ectropion:
Involutional or senile ectropion is a common form of ectropion. It has many features similar to involutional entropion like it affects the lower lid of elderly patients and the ageing changes for both are similar. Following age related changes contribute to involutional ectropion.
– Horizontal lid laxity leads to excessive eyelid length.
– Tarsoligamentous sling which support the eyelid by attachment to the orbital rim via canthal tendons (both medial and lateral) is lax. Medial and lateral canthal tendons are also known as medial and lateral palpebral ligaments respectively. (http://emedicine.medscape.com/article/834932-overview#a6)
– Weakness of pre-tarsal orbicularis oculi.
Chronic pressure of ocular prosthesis in anophthalmic (absence of eyeball) socket may produce involutional ectropion.
Cicatricial ectropion is caused due to scarring or contracture of skin and underlying tissues. Anterior lamella comprising of skin and orbicularis oculi muscle is shortened. This leads to pulling away of the eyelid from the globe.
Important causes include:-
– Facial burns
– Excessive skin excision or laser burn in blepharoplasty (eyelid surgery).
Paralytic ectropion may occur with palsy of seventh cranial nerve. Paralytic ectropion is caused by decreased tone of orbicularis oculi muscle due to its involvement in seventh cranial nerve palsy.
Important causes of seventh cranial nerve palsy are:-
– Bell palsy.
– Parotid gland infiltration or tumour.
– Cerebellopontine angle mass.
– Herpes zoster oticus.
Congenital ectropion is a rare bilateral condition. Often the cause is vertical deficiency of anterior lamella.
Congenital ectropion may occur in isolation or may be associated with other conditions such as:-
– Blepharophimosis syndrome.
– Buphthalmos (Enlarged eyeball due to congenital glaucoma).
– Microphthalmos (small eyeball).
– Orbital cyst.
– Down syndrome.
Mechanical ectropion may occur with lid tumours such as neurofibromas.
Risk factors for Ectropion:
Certain factors contribute in development of ectropion such as:-
– Frequent rubbing of eyelids.
– Repeated pulling of eyelids (e.g. as in contact lens wearer).
– Loss of lid elasticity with ageing.
– Skin conditions involving eyelids.
– Prior eyelid surgery.
– Long term use of eye drops such as dorzolamide and brimodine.
– Inflammatory skin conditions involving eyelids.
– Midfacial hypoplasia.
Diagnosis depends upon elucidation of causative factors and clinical examination.
Examination may show features like:-
– Signs of skin scarring, irritation or infection.
– In hypoplastic midface, inferior orbital margin is located posteriorly relative to the globe.
– Eversion of eyelid.
– Examination of lid margin structures may show madarosis (absence or loss of eye lashes), chronic blepharitis, ulceration or infiltration.
– In punctal ectropion, punctum may rotate away with medial laxity and no longer make contact with ocular surface.
– Conjunctival examination may show dry eye features due to keratinisation induced by chronic irritation, hypertrophy or scarring.
– Cornea may show abrasion, scarring, thinning, neovascularisation or ulceration.
– Patient may show horizontal laxity of medial and/or lateral canthal tendons.
– Horizontal lid laxity: Horizontal lid laxity may be assessed by placing the thumb beneath lateral canthus and pushing the eyelid laterally and superiorly. Involutional ectropion disappears with this manoeuvre.
– Eyelid distraction test: Eyelid distraction test is done by pulling the lid away from the globe. Normal lid distraction is between 2-3mm. In horizontal lid laxity, distraction is more than 5mm.
– Snap back test: Examiner pulls lower lid inferiorly and observe 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.
– Horizontal lid laxity: Horizontal lid laxity may be assessed by placing the thumb beneath lateral canthus and pushing the eyelid laterally and superiorly. If the lower lid margin does not extend 2mm above the lower limbus, then cicatricial ectropion is considered.
– In cicatricial ectropion, eyelid malposition often becomes accentuated by asking the patient to look upward and open mouth at the same time. By this manoeuvre, anterior lamella is maximally stretched.
– Signs of seventh cranial nerve palsy such as weakness of facial muscles, disparity between spontaneous and voluntary closure of eyelid, presence or absence of Bell phenomenon and inability to close the eyelids may be present.
– Exposure keratopathy caused by incomplete blinking and lagophthalmos (inability to close the eyelids).
– Epiphora produced by failure of lacrimal pump mechanism and increase in tear production due to corneal exposure.
– Eyelid retraction.
– Deformity such as brow ptosis.
– Congenital ectropion may show features of associated disease such as Blepharophimosis syndrome, microphthalmos (small eyeball) or Down syndrome.
Mechanical ectropion will show features of associated tumour.
Ectropion should be differentiated from conditions like:-
– Eyelid retraction secondary to proptosis.
– Eyelid malignancy e.g. basal cell carcinoma or squamous cell carcinoma.
Management should be under medical supervision.
Medical treatment may be needed in:-
– Patient who decline surgery.
– As temporising measure until patient can have surgery.
– Patient is too sick for surgical intervention.
– Patient who may improve spontaneously e.g. patients with ectropion induced by long term use of eye drops may resolve with discontinuation or patients suffering from inflammatory skin conditions involving eyelid may have improvement or reversal of ectropion on improvement of inflammation.
Medical non-invasive management may involve:-
– Lubrication of the ocular surface: Lubrication and moisture shields are helpful in corneal exposure. Lubricating ointment may be used in keratinised conjunctiva.
– Horizontal taping of the eyelid: Taping the lateral canthal skin superotemporally provides temporary relief in patients with new onset seventh cranial nerve palsy.
– Patients with early punctal ectropion should wipe the eyelids in a direction up and in (toward the nose) to avoid worsening of medial ectropion.
– In cicatricial ectropion, digital massage may help in stretching the scar.
– Medial ectropion may be corrected by Cautery puncture, conjunctivoplasty or lazy-T procedure.
– Extensive ectropion is corrected by Bick procedure or modified Kunht-Szymanowski procedure.
– Cicatricial ectropion is corrected by excision of scar and skin grafting.
– Relief may be provided with tarsorrhaphy or canthoplasty.
– Severe cases may be treated with full-thickness skin graft to replace vertical skin defect.
Mechanical ectropion may require excision of tumour.