entropion of the eyelid
This is the turning inwards of the eyelid. Involutional, spastic or senile entropion always affects the lower lid. It is caused by atrophic changes in the lower lid retractors, tarsal plate and adjacent fat in which the marginal fibres of the orbicularis oculi contract more strongly than the peripheral fibres. It can be elicited by asking the patient to squeeze the eyes tightly shut; upon opening, the lower lid will be seen to be turned inwards.
Cicatricial entropion may affect either the upper or the lower lid. It results from conjunctival and tarsal scar formation, for example, due to burns, Stevens - Johnson's syndrome, and trachoma.
Congenital entropion is rare. It results from rotation of the lid margin towards the cornea. It is to be distinguished from an epiblepharon in which the pretarsal skin and muscle causes the lashes to rotate around the tarsal border. Epiblepharon is most common in Asians.
Irrespective of the initial cause, the condition is exacerbated by the inturned eyelashes causing conjunctival and corneal irritation, leading to further entropion.
Sedatives and lubricants may give some relief. Surgery designed to lengthen the lower fibres of the orbicularis or to weaken the marginal fibres is the treatment of choice. If there is irritation from the lashes, these may be removed and a contact lens worn.
Last reviewed 01/2018