Ptosis

Droopy eyelid, congenital or acquired

Overview

Ptosis, or blepharoptosis, is a drooping of the upper eyelid. Congenital ptosis is usually caused by poor development of the levator palpebrae superioris, the muscle that lifts the lid, and in children it can cause amblyopia if the lid covers the pupil or induces astigmatism. Acquired ptosis is most often aponeurotic, caused by stretching or detachment of the levator tendon with aging, after eye surgery, or with long term contact lens wear. Other types are myogenic, as in myasthenia gravis, where the droop characteristically fluctuates and worsens with fatigue, and in myotonic dystrophy and mitochondrial myopathies, neurogenic, as in third nerve palsy and Horner syndrome, and mechanical, from the weight of a lid mass. A third nerve palsy involving the pupil is evaluated urgently because it can signal an intracranial aneurysm. Ptosis is distinguished from dermatochalasis, excess upper lid skin. Treatment is directed at the cause, and structural ptosis is usually corrected surgically by levator advancement, Muller muscle resection, or a frontalis sling.