Entropion is inversion of an eyelid. Ectropion is eversion of the lower eyelid.
Entropion
SCIENCE PHOTO LIBRARY
Entropion (inversion of an eyelid) is caused by age-related tissue relaxation, postinfectious changes (particularly trachoma), autoimmune skin disease (eg, mucous membrane pemphigoid), posttraumatic changes, or blepharospasm. Eyelashes rub against the globe and may lead to corneal ulceration and scarring. Symptoms can include foreign body sensation, tearing, and red eye. Diagnosis is clinical. Definitive treatment is surgery or treatment of the underlying etiology (eg, infection or inflammation) (1).
Ectropion
MID ESSEX HOSPITAL SERVICES NHS TRUST/SCIENCE PHOTO LIBRARY
Ectropion (eversion of the lower eyelid) is caused by age-related tissue relaxation, cranial nerve VII palsy, and posttraumatic or postsurgical changes. Symptoms are tearing (due to poor drainage of tears through the nasolacrimal system, which may no longer contact the globe) and symptoms of dry eyes. Diagnosis is clinical. Symptomatic treatment can include tear supplements and, at night, ocular lubricants; definitive treatment is surgery.
General reference
1. Vallabhanath P, Carter SR: Ectropion and entropion. Curr Opin Ophthalmol 11(5):345-351, 2000. doi: 10.1097/00055735-200010000-00010.PMID: 11148701
