Why do I have ptosis (a drooping eyelid)?
Often when patients notice a drooping eyelid in one or both eyes, the first question that comes to mind is “Why did this happen?” This article was written to elucidate the different causes of ptosis of the eyelid. As an oculofacial plastic surgeon, it is critical to determine the causes of ptosis in order the properly fix it. Different causes of ptosis are treated with different things. Some types of ptosis are treated with medication. Some are treated with varying eyelid surgeries that depend on the type of ptosis in order to give the best odds of repair.
Congenital ptosis is caused in utero by a muscle (levator) that is used to elevate the eyelid not properly developing. When this happens, the eyelid is droopy. Depending on how maldeveloped the eyelid muscle is the eyelid may be more or less droopy. We don’t fully understand why the muscle doesn’t develop in some babies. Sometimes if a muscle is a little maldeveloped, the eyelid will be slightly droopy but over time as the patient ages, the muscle gets weaker causing the ptosis to get worse. Congenital ptosis is often treated with a sling procedure to try to connect the eyelid muscle to the eyebrow.
Some the causes of congenital ptosis include:
Congenital third nerve palsy
Marcus Gunn Jaw Wink
Double Elevator Palsy
These are investigated by your oculoplastic surgeon to determine the proper treatment.
Acquired Ptosis is basically any ptosis that occurs after birth. There are many causes of acquired ptosis but I will discuss the most common.
Over time the eyelid muscle can loosen in the eyelid. Additionally, sometimes the eyelid muscle can break down or degenerate. Both cases will result in the eyelid becoming droopy. Most patients will note a drooping of the eyelid often gradually with time. Contact lens use can contribute to this along with any surgeries on the eyeball itself.
Obviously if one is cut on the eyelid and the eyelid muscle gets directly damaged, the eyelid will become droopy. If the nerve to the eyelid muscle is damaged, it will also not function properly. If there is trauma and the upper eyelid is scarred down to the lower eyelid, the eyelid will be droopy as well.
Any previous surgery on the eye itself requires something called a speculum to be used. This is an instrument that can stretch the eyelid muscle and cause it to weaken. For example, if the eyelid muscle is weak already and then a speculum is placed, it may be tipped over to cause the eyelid to droop. The more surgeries one has, the more chance the eyelid can become droopy. There is no way to prevent it and of course one has to have a way to keep the eyelid open when performing surgery on the eye.
When a nerve that travels from the brain to the neck is damaged, the nerve supplying one of the muscles of eyelid elevation gets damaged, the eyelid can droop. Often the pupil is smaller in this case. The underlying cause of the drooping has to be determined in this case and must be treated. If an aneurysm or tumour is pressing against the nerve that would have to be sought out and corrected.
Third Nerve Palsy
This is another cause of drooping eyelids that is often caused by a stroke, tumor, or trauma. In this case the patient will have double vision, a bigger pupil and often a very drooping eyelid. Again, the underlying cause must be determined to make sure it is not a tumor or aneurysm.
This is an autoimmune condition that results in the muscle strength not being as effective secondary to an immune system problem. Often patients will complain of worse drooping as the day progresses. They will often say things are better after a nap or rest. Occasionally double vision can occur as well as body weakness. The treatment for this is medical only. A patient with Myasthenia usually does not do well with surgery.
Floppy Eyelid Syndrome
This is a disease seen in patients who have sleep apnea. In this case the eyelid become droopy because the eyelid is getting loose. They are not 100 percent sure why some patients have floppy eyelid who have sleep apnea. One theory is that they have the same loose tissue in their throat that they have in the eyelid. A second theory is that the eyelid becomes loose with time as they sleep on their stomachs to prevent their airway from collapsing during sleep. Sleep apnea ptosis is treated with eyelid surgery but also the underlying sleep apnea has to be treated as well. It is a relatively difficult type of ptosis to repair because the eyelid has lost its “meat’ so to speak.
Contact Lens Overuse
Contact lens wear can cause bumps to develop on the underside of the eyelid. These bumps cause the eyelid to droop and not sit properly on the eye. A contact lens holiday (ie wearing glasses for several months) usually resolves this. Contact lens overuse is often seen in young patients with ptosis
A growth in the eye socket or eyelid can limit the movement of the eyelid or weigh down the eyelid. This is something that is treated by removing or treating the mass. Masses in the eye socket can include lymphoma, sarcoidosis of the lacrimal gland, squamous cell carcinoma among others. Even a simple eyelid growth can weight down the eyelid if it gets big enough.
As can be seen this is just the tip of the iceberg for causes of ptosis. There is no one cause though indirectly the problem is always due to the muscle of the eyelid. Why the eyelid muscle (levator) is not working well can be explained by many different reasons. Hopefully this can help patients see the complexity of eyelid ptosis and even the repair. Thanks so much