Facial Nerve Palsy | Facial Paralysis
Facial palsy or Bell’s palsy is paralysis of part of the face caused by non-functioning of the facial nerve known as the seventh cranial nerve that controls the muscles, especially around the eye and to the mouth.
Facial palsy can be congenital or acquired, possibly following a viral illness (like herpes simplex and shingles) or through no obvious cause. Sometimes a tumour can compress and damage the nerve. Other causes include serious infections and skull fracture.
Facial paralysis usually affects one side of the face. The symptoms include having a droopy eyebrow, difficulty closing the eye or blinking, thus making the eye very dry, a droopy corner of the mouth and an inability to whistle.
How Does Facial Palsy Affect Eyes?
This has a significant impact on the health of your eyes. The upper eyelid can be a little too high and the lower eyelid can sag and turn outward (ectropion), resulting in a watering eye, inability to close the eye and exposure or drying of the cornea. This can cause dry eye syndrome whereby the eyes tend to become red, vision can blur and sight is occasionally affected by ulceration and scarring.
More unusual problems include losing the use of the nerve that controls sensation in the eye. This usually happens as a result of a large, benign brain tumour, affecting both the facial nerve and other nerves of the eye. Such patients may suffer a lack of sensation on the surface of the eye (cornea). This prevents them from feeling dryness, or any kind of foreign bodies or injuries sustained to the eye. This puts them at risk of developing a corneal ulcer and suffering severe damage to their sight.
Crocodile tears are another rare consequence of facial nerve paralysis. This happens if the damaged nerve tries to grow back and goes towards the tear gland and to the muscles of the jaw. This results in embarrassing tears when the patient chews on food. A patient may also have trouble closing of the eyelid and have muscle spasms in the eyelid, cheek and around the mouth.
Treatment and Recovery
1. Initial Treatment
Initial treatment for facial palsy due to an exposed eye usually includes using of ocular lubricants, such as artificial tears and eye ointments. Frequent use of artificial tear drops in the day time and lubricant ointment at night may be needed. Ointment can be used in the day time also, but this does cause a lot of blurring of the vision.
A temporary external weight may be applied to the eyelid skin to aid blink-closure in the day. Other options include wearing glasses with visors or wraparounds, something similar to goggles to keep the moisture in. You can also use humidifiers at home and in the workplace to aid with keeping the air moist.
For some, it is important to carry out daily hot compresses in the evening or before bedtime to improve eyelid margin. Punctal plugs may be recommended for those if the lacrimal nerve is involved and the eye is very dry.
2. Surgical Treatment
If you develop an outwardly turned eyelid, you may need surgery to repair it. Most patients with a permanent palsy will require additional help with eyelid closure in the form of eyelid surgery.
When to Consider?
If there is no damage, we will advise patients to wait roughly 3 months before considering any surgery to allow spontaneous recovery of the facial nerve. Surgery is customised according to the patient’s needs and problems. Some patients need surgery to improve the outward turning of the lower eyelid. Sometimes patients need surgery to improve the upper eyelid closure and some need eyebrow lifting to improve cosmesis due to eyebrow droop.
If you have mild palsies you will require less complicated procedures than those with more severe palsies.
Aims of surgery of the eyelids are to:
Increase the wetting of the cornea
Improve the position of the lower eyelid which may be lax
Improve the outlook and reduce asymmetry between the two sides of the face (can either be done using surgery or minimally invasive techniques)