Saturday, November 8, 2014

Jumping, twitching eyelids

‘Dr, my eyes are jumping!’ Goes the patient sitting in front of me. In fact, when I have a closer look, I see that part of the lower eyelid of this patient seems to be shivering. For a few seconds, and it stops. And starts again.

This Youtube video shows a pretty good example of common eyelid twitching: https://www.youtube.com/watch?v=sphQNOihpf0

The patient is having one of the most common complaints seen by eye doctors, and fortunately it is also one of the most benign of conditions. There are in fact several types of eyelid twitching, with the most common type called ‘myokymia’. This condition can come and go by itself and often does not need any special treatment, although it can be quite annoying.

There are also other types of eyelid twitching which are more severe. One of them is called ‘hemifacial spasm’, in which one side of the face, and eyelids on the same side, twitches at the same time. If this happens on both sides at the same time, then it is called ‘blepharospasm’. Both of these kinds of twitching can range from mild to severe, with some bad cases of blepharospasm being unable to open their eyes. Fortunately, these cases are very rare.

Causes of twitching eyelids

Myokymia (Common eyelid twitching)
Although the exact mechanism that causes this is not known, common eyelid twitching is associated with the following:
·         Excessive coffee or other caffeine intake
·         Eye strain which may be associated with incorrect glasses prescription
·         Lack of sleep or fatigue
·         Eye irritation, which can be caused by dry eyes or inflamed eyelids/crusty eyelids

Hemifacial spasm
This uncommon condition can be caused by a small blood vessel near the ear that presses on the facial nerve. Other growths or injuries to the facial nerve may also cause this.

Blepharospasm
In blepharospasm, both eyelids blink together and if the condition gets worse, the eyelids may intermittently squeeze tightly together. Most of the time, the cause is unknown, but this condition can be made worse by any kind of eye irritation. It can occasionally also be associated with the use of drugs such as those used for Parkinson’s disease, and prolonged use of sleeping tablets in the benzodiazepine class.
The origin of the condition is probably different from common eyelid twitching, in that for blepharospasm, the problem is likely to come from abnormal activity in the brain cells, rather than from the nerve endings or muscle cells in common twitching.

Treatments for the twitching eyelid

In cases of common eyelid twitching, possible associated factors like a high coffee intake should be looked into and addressed. From an eye doctor’s point of view, specific things to check include the accuracy of the spectacle power and also the presence of any eye dryness.

Dryness of the eyes is a very common problem around the world, and is associated with both our changing activities as well as environment. The wearing of contact lenses, excessive computer or phone viewing, and the presence of dry air in air conditioned environments all make a pre-existing dry eye problem worse. Simple measures include the use of artificial tear eyedrops, and sometimes tear duct plugging can also be very useful.

In persistent cases, sometimes mild relaxant medications can help, such as Lexotan.

Botox


Botox, or Botulinum toxin, is made by a bacterium that used to cause severe sickness in people who ate from spoiled canned foods. However, when purified and used in proper dosages, it has become a very useful medication for many different conditions. Most famously, it is used to reduce the appearance of wrinkles or ‘crow’s feet’ on the face.

Botox works by ‘paralyzing’ temporarily a very focused set of muscles. It can be used for any kind of stubborn eyelid twitching, including all three types mentioned above. However, it is only extremely rarely used for common eyelid twitching.

The effect of Botox lasts for a few months, and as it fades, the twitching may come back again. If this happens, Botox can be injected again. The good news is that with Botox, often with several injections, the muscle that twitches become weaker, so the effect may become more prolonged after several injections.

Side effects of Botox:
Botox in the hands of an experienced doctor is very safe. Mild bruising can sometimes be seen around the injection site. Rarely, if the medicine spreads to affect certain muscles, the eyelids may droop, or it may be difficult to close the eyes fully. The latter can exacerbate dry eyes. Most of these side effects are temporary, and will get better by themselves as the effect of the medicine wears off.

Hemifacial spasm
In some cases of hemifacial spasm, especially where it is getting worse or associated with facial weakness, an MRI scan can be performed to look for any possible pressure on the facial nerve which controls facial movements. If something is found such as a dilated blood vessel, surgery (called microvascular decompression) can be considered but does carry some risks.

Blepharospasm
Blepharospasm can be a difficult condition to treat and is fortunately rare. Initial treatment includes looking for contributing factors such as eye dryness or eyelid problems. Relaxants such as clonazepam or anticonvulsant medications such as carbamazepine can be used, although they do not always work satisfactorily. Botox is very helpful, and in the worst cases, surgery can be considered to weaken the muscles which are having spasms.

Summary
Most cases of eyelid twitching are annoying but harmless. Simple measures that address risk factors like fatigue and excessive caffeine will help. In more stubborn cases, a visit to your friendly eye doctor can help greatly too!


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