Ectropion may:
(1) be unilateral or bilateral
(2) be symmetrical or asymmetrical (if bilateral)
(3) affect the upper or lower eyelid or both
Causes of ectropion:
(1) congenital, present since birth
(2) senile (involutional), associated with skin, tendon and/or muscle laxity
(3) paralysis of the orbicularis oculi muscle (facial nerve palsy, other)
(4) fibrosis-related (cicatricial), associated with scarring (after burn, surgery, injury, etc)
(5) tumor-related
(6) infiltrative (edema, inflammation, other) involving conjunctiva and/or eyelid
