Epiblepharon is the presence of a fold in skin and orbicularis oculi muscle of the lower eyelids which may cause eyelashes to rub against the cornea (trichiasis). There is vertical orientation of the eyelashes. It may be associated with weakness of inferior oblique muscle. It usually affects nasal one-third of the lower lid and is usually bilateral. There may be presence of coexistent entropion. This condition may be seen in upper eyelid as well. This condition may be autosomal dominant or sporadic and is usually common in Asian population. Epiblepharon may be self-limiting in many patients, since it decreases or diminishes with facial growth. The word epi means on and blepharos means eyelid.
Epiblepharon is mostly a paediatric condition, but it is often reported in adults as well. Acquired epiblepharon has been reported in thyroid eye disease and other conditions of proptosis.
Epiblepharon may be identified by the extra eyelid fold in lower eyelid and it resolves when the pressure of the fold is taken away from the lower eyelid.
About 80% of children with epiblepharon have no ocular complaints.Some patients show symptoms at all times, whereas others are symptomatic only in down gaze. Epiblepharon may present with symptoms such as
- Watering or epiphora.
- Foreign body sensation.
- Corneal epithelial defect.
- Rubbing of eyes.
- Frequent blinking.
Epiblepharon may be associated with several causes such as
- Poor development of the eyelid retractors.
- Failure of retractors to gain access to skin.
- Hypertrophy of orbicularis oculi muscle.
- Insertion of pre-tarsal part of orbicularis oculi muscle close to the eyelid margin with weak attachment of orbicularis oculi muscle and skin to underlying tarsus.
These underlying processes may result in pre-tarsal orbicularis muscle and eyelid skin that overrides the eyelid margin, thereby causing inward rotation of cilia.
In case of thyroid related proptosis causing acquired epiblepharon, the aetiology is felt to be increased intra-orbital pressure leading to an overriding anterior lamella of lid.
Epiblepharon is diagnosed based on clinical features. Epiblepharon is typically bilateral and it generally affects medial part of lower eyelids.
Symptoms range from none to features of eye irritation. The severity of epiblepharon symptoms may be associated with the type and number of eyelashes irritating the eyes. Few and fine eyelashes are often less symptomatic than thick and plentiful lashes. Due to this variability, symptoms of epiblepharon may change with age. Child may develop decreased visual acuity due to development of induced astigmatism.
Khwarg and Lee (1997) proposed a grading scale for severity of lower eyelid epiblepharon based on height of the skin-fold, area of corneal touch by cilia, and area of corneal erosion.
Epiblepharon may be differentiated from
- Congenital entropion: It is characterised by an in-turning of the eyelid margin. Congenital entropion does not improve over the time and surgical correction is usually required.
- Trichiasis: Trichiasis is an acquired condition characterised by posterior misdirection of previously normal eye lashes. The misdirected lashes may be diffuse involving the entire lid (diffuse trichiasis) or may involve a small segment of it (simple trichiasis).
- Distichiasis:Distichiasisis characterised by an extra row of eyelashes emanating from the meibomian gland orifices. Like epiblepharon, eyelid margin is in its normal position.
- Epicanthus: Epicanthus may result similar appearing fold of skin close to the eyelid margin. An associated semicircular epicanthal fold may contribute to additional medial canthal tension and worsens epiblepharon.
- Congenital nasolacrimal duct obstruction: If epiphora persists after treatment of epiblepharon, congenital nasolacrimal duct obstruction should be considered.
- Allergic conjunctivitis: Allergic conjunctivitis may also be considered in cases of chronic bilateral eye irritation, watering, and redness of eyes.
Epiblepharon may be managed conservatively unless there are issues related to eyelash contact with ocular surface or there are concerns about refractive amblyopia.
- Lubricating artificial tears: Lubricating artificial tears may be used as soothing agents. Even in the presence of corneal irritation, some children do not have any complaint.
- Hyaluronic acid: Hyaluronic acid injection into sub-orbicularis muscle space has been described as an effective temporising approach until self-correction takes place with age.
Some cases of epiblepharon resolve spontaneously as the nasal bridge grows.
Surgical intervention is required in cases of corneal keratopathy and it involve procedures such as
- Eyelid everting sutures: A non-incisional approach involves placement of eyelid everting sutures. This procedure is associated with a high recurrence rate.
- Excision of orbicularis oculi muscle and skin: In this procedure, redundant skin and orbicularis oculi muscle is excised in the form of a spindle. This procedure is associated with formation of scar tissue.
- Transconjunctival approach: An effective transconjunctival approach (Wladis, 2014) has been described with low recurrence rate and no external scar.
Occasionally, mucous membrane graft to the posterior tarsus and lid margin may be required to cover the raw surfaces.
Prognosis of epiblepharon once corrected is good, and it usually does not recur.
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