Synonyms in a broader sense
Hanging, upper eyelid; Greek lowering, falling down
Definition
Ptosis is not a disease in itself, but a symptom that can have various causes. It can be recognized by the fact that the upper eyelid of one or both eyes, despite the patient’s attempt to open the eyes wide, protrudes so far down that the upper iris and pupil are completely or partially covered. Doctors distinguish between congenital and acquired ptosis.
General information
Congenital ptosis congenita is inherited and is based on a genetic defect that limits the function of the muscle that lifts the upper limb. This defect is usually limited to only one eye and leads to the person concerned being restricted in his or her spatial perception. This is because the drooping eyelid prevents the person from seeing with both eyes (so-called binocular vision).
If left untreated, the hidden eye becomes weaker and weaker over the years and a permanent weakness of vision (amblyopia) develops, which can progress to blindness. A prominent example of unilateral, congenital ptosis is the entertainer Karl Dall. Acquired ptosis is usually the result of accidents, age-related tissue weakness or other diseases that have affected the eyelid lifter muscle.
The clinical picture is in principle analogous to congenital ptosis, but here the drooping eyelid often occurs on both sides. Direct lesions of nerves can also result in ptosis. This is the case with sympathetic ptosis.
While ptosis sympathica is characterized by a slight lowering of the eyelid, the pupil is additionally restricted in its opening function. As a result, the eye appears to be located somewhat deeper in the orbit. The trigger is often a stroke or meningitis.
Various systemic muscle diseases (such as myasthenia gravis) as well as intoxications with snake venom or dangerous chemicals can also paralyze the muscles and attack the nerves. Ptosis must be distinguished from apparent ptosis (pseudoptosis) and sunken eyes (enophthalmos). Apparent ptosis can be an expression of the decreasing connective tissue tension of the skin with age. The sunken eye describes the sinking of the eyeball back into the eye socket due to a fracture of the floor of the eye socket. Other causes of ptosis may be: