Ptosis (pronounced toe-sis) is a drooping or lowered position of the upper eyelid margin or edge (where the lashes come out), as opposed to drooping of excess skin over the lashes (dermatochalasis). When the lid margin/edge begins to cross the pupil with eyes open, vision can become obstructed.
There are a variety of causes for this condition. Most commonly, there is a slippage or dis-insertion of the muscle that elevates the upper eyelid (called the levator). This can occur with age, stretching of the eyelid after swelling, contact lens wear or ocular surgery. The correction of this type of ptosis involves a delicate outpatient surgery.
Patients born with ptosis (other than that caused by birth trauma to the eyelid) can have what is termed congenital ptosis. In this condition, the muscle that elevates the eyelid (levator) is not formed normally. This can be an urgent problem if the eyelid covers the pupil while the child is awake because visual input to each eye can lead to permanent poor vision in the occluded eye (amblyopia).
Other causes of ptosis include neurologic problems such as third cranial nerve palsy, Horner’s syndrome, eyelid trauma, Myasthenia gravis (ocular or systemic), inadvertent Botox placement and orbital tumors. Clinical evaluation is necessary to determine the cause of the ptosis and choose the appropriate treatment.