Definition: (Ptosis): Ptosis is the medical term for a drooping eyelid. It refers only to the upper eyelid; it does not refer to lower eyelid sagging. Upper eyelid drooping can sometimes affect your vision if the drooping is severe. Ptosis is not a disease, but a symptom of another condition that must be treated.
Causes: Ptosis can be caused by a number of factors that affect the muscles, nerves, or skin of the eyelids. The muscles that allow your eyelids to move up and down—called the levator muscles—can become weakened from age or injury. In addition, some people may be born with weaker-than-normal eye muscles, thereby developing ptosis at a young age.
Nerve damage can contribute to ptosis as well. A common cause of ptosis is Horner syndrome. Horner syndrome is a form of nerve damage that occurs in the face and eyes, and is usually the result of an underlying condition. Stroke and other brain injuries, spinal cord injuries, and some forms of lung cancer can cause Horner syndrome and ptosis.
Some chronic conditions, including diabetes and myasthenia gravis, may also increase your risk of ptosis. Diabetes—your body’s inability to process sugar correctly—can lead to a number of complications, including eye disease. Myasthenia gravis is an autoimmune disease that affects the way your muscles and nerves communicate.
Cluster headaches can also cause ptosis in some people. Cluster headaches are severe headaches that strike in a frequent pattern for a period of time (cluster periods) and then go into remission.
Classification: Depending upon the cause it can be classified into:
- Neurogenic ptosis which includes oculomotor nerve palsy, Horner’s syndrome, Marcus Gunn Jaw winking syndrome third cranial nerve misdirection.
- Myogenic ptosis which includes myasthenia gravis, myotonic dystrophy ocular myopathy, simple congenital ptosis
- Aponeurotic ptosis which may be involutional or post-operative
- Mechanical ptosis which occurs due to edema or tumors of the upper lid
- Neurotoxic ptosis which is a classic symptom of envenomation by elapids such as cobras. Bilateral ptosis is usually accompanied bydiplopia, dysphagia and/or progressive muscular paralysis. Regardless, neurotoxic ptosis is a precursor to respiratory failure and eventual suffocation caused by complete paralysis of the thoracic diaphragm. It is therefore a medical emergency and immediate treatment is required.
- Pseudo ptosis due to:
- Lack of lid support: empty socket or atrophic globe.
- Higher lid position on the other side: as in lid retraction
Symptoms: The primary symptom of ptosis is a visible drooping of the upper eyelid. Ptosis can affect children and adults at any stage of life. You may notice symptoms in one or both eyes. Individuals who are born with drooping eyelids have congenital ptosis. One of the signs of congenital ptosis is having uneven creases in the eyelids.
Children who have ptosis may use certain gestures or body positions common to people with this symptom. Frequent eyebrow raising and head tilting can indicate that ptosis is interfering with normal sight.
Diagnosing: The American Academy of Ophthalmology stresses the importance of eye exams for children and adults with ptosis . A vision test that uses an eye chart can help determine if eyelid drooping is compromising your or your child’s vision.
Blood tests used to detect diabetes and autoimmune conditions can help diagnose the underlying cause of ptosis. Your doctor may also perform X-ray to see if structural abnormalities around the eye(s) are causing the problem.
Treatment: Aponeurotic and congenital ptosis may require surgical correction if severe enough to interfere with vision or if cosmetics is a concern. Treatment depends on the type of ptosis and is usually performed by an ophthalmic plastic and reconstructive surgeon, specializing in diseases and problems of the eyelid.
Surgical procedures include:
- Levator resection
- Muller muscle resection
- Frontalis sling operation
Non-surgical modalities like the use of “crutch” glasses or special Scleral contact lenses to support the eyelid may also be used.
Ptosis that is caused by a disease will improve if the disease is treated successfully.