Eyelid position is an important indicator of ophthalmic disease. A drooping lid (ptosis) can impede vision, an out-fixed lid (ectropion) can result in corneal exposure, and an infixed lid (entropion) can rub against the cornea. These abnormalities can be caused by inflammation, scarring, paralysis, and muscle laxity.
Entropion and ectropion are more commonly seen in the lower eyelids compared to ptosis - which is seen in the upper eyelids.
Ectropion
Ectropion is an outwardly pulled eyelid. It can stop the eyes from closing properly (lagophthalmos). This can compromise the tear film and cause ocular surface irritation.
Types of Ectropion |
Description |
|---|---|
Involutional |
The commonest type. Caused by horizontal lid laxity and often seen in the elderly. |
Cicatricial |
Shortening of the anterior lamella by inflammation and scarring. It is caused by underlying conditions such as burns and dermatitis. |
Paralytic |
Orbicularis weakness caused by facial nerve palsy. Corneal sensation can also be compromised in these patients. |
Congenital |
Typically due to a shortage of skin. Can be seen in Down syndrome and prematurity. |
Management
- Management depends on the mechanism of ectropion.
- Horizontal lid laxity → lateral tarsal strip
- Vertical lid laxity → Diamond excision
- Cicatrix → skin gaining procedures such as grafts and flaps
- Ocular surface irritation can occur as a result of dry eye and is discussed further in the lacrimal section
Entropion
Entropion is an inwardly rolled eyelid. It can lead to corneal ulceration as the inwards turning eyelashes rub against the cornea whilst blinking.
Pathology
Involutional
- Commonest type**.**
- Caused by lower retractor weakness/dehiscence.
Cicatricial
- Caused by shortening of the posterior lamella by vertical scarring.
- Most commonly caused by trachoma (upper lid)
Management
- Depends on the mechanism of entropion
- Retractor weakness → Everting sutures, transverse tarsotomy, or Jones procedure
- Scarring → Membrane graft or posterior lamella reconstruction
- Botox can be used to weaken overactive muscles
Ptosis
An abnormally droopy upper eyelid. It can be congenital but is most commonly acquired. This section summarises the types of ptosis.
Involutional
- The most common type.
- Caused by dehiscence of the levator palpebrae superioris from its attachment to the levator aponeurosis.
- Risk is increased with age and after surgery.
- Treatment → anterior levator advancement surgery
Neurogenic
CN3 Palsy
- Loss of levator function leads to ptosis.
- Abnormalities in eye movements and a mydriatic pupil can also be seen.
- Spontaneous resolution is common so treatment (with frontalis suspension surgery) is typically delayed.
Horner Syndrome
- Discussed at length in the ‘neuro-ophthalmology’ chapter
- Surgical management is with Levator resection (strengthens muscle) or Mullerectomy.
Myasthenia Gravis
- Discussed at length in the ‘neuro-ophthalmology’ chapter
- Ptosis worsens towards the end of the day.
Congenital Ptosis
Isolated congenital ptosis
- Developmental myopathy of the levator palpebrae superioris.
- Typically unilateral, with an absent upper lid crease.
- Treatment depends on levator function:
- Poor function → frontalis suspension.
- Preserved function → anterior levator resection.
Blepharophimosis syndrome
- Characterised by a shortened horizontal palpebral fissure and telecanthus.
- AD inheritance
Marcus Gunn jaw-winking syndrome
- Characteristic elevation of the ptotic lid whilst chewing.
- Thought to be caused by developmental CN5 misdirection to the levator palpebrae superioris.
Pseudoptosis
Pseudoptosis is a lid that appears droopy, but is actually within normal range when measured.
Blepharochalasis
- Abnormally elastic lid tissue leads to excess skin folds and oedema
Dermatochalasis
- Commonly seen in the elderly.
- Upper lid skin hangs and folds.
Brow ptosis
- Frontalis dysfunction leads to lowering of the entire eyebrow region.
It’s due to abnormal size/position of the eyeball (enophthalmos or microphthalmos) or abnormal growth of lid tissue (Blepharochalasis or Dermatochalasis) or abnormalities on the contralateral eye which make the ipsilateral lid look ptotic (e.g contralateral lid retraction/proptosis)
