Congenital Ptosis (Drooping Eyelids)
Definition and causes
“Ptosis” is the medical term for a drooping upper eyelid. There are two reasons why an eyelid droops: there’s a either a problem with the “levator” muscles that lift the eyelids, or a problem with the nerve that controls them. There are a number of causes – trauma, infection, cancer, autoimmune or inflammatory disease, and sometimes ptosis can be hereditary.
It’s caused by a dysfunction in either the muscles that raise the eyelid, or the nerves that control those muscles. Ptosis can occur on its own, but it can also be associated with trauma, autoimmune or inflammatory disease, infection, cancer, and in some cases, hereditary disease.
Sometimes, the ptosis is mild, and the upper eyelid droops only slightly. But in moderate-to-severe cases, the upper lid may partially or completely cover the pupil. This is of particular concern in children, ptosis that covers the pupil can cause amblyopia: the part of the brain that deals with vision from that eye just doesn’t develop properly as it isn’t receiving as much information from this partially closed eye.
Instinctively, children try to compensate for this by the following behaviours:
- Putting their head back and lifting their chin
- Lifting the drooping eyelid with their fingers
- Raising the eyebrow to help lift the upper eyelid more.
But if you have a child with an eyelid that covers the pupil and they don’t use these compensating mechanisms, then it’s important that they get seen by a professional quickly: the ptosis can cause visual suppression, and can leave your child with permanent, lifelong amblyopia.
Congenital ptosis is usually based on a malformation of the muscle (levator muscle), which should raise the upper eyelid. This change can affect either one or both upper eyelids. Other, rarer causes of congenital ptosis may include: certain muscle diseases, tumors of the eyelids or neurological disorders.
There are two surgical techniques that can be used to correct ptosis – levator resection and frontal suspension. Which one is chosen depends on the condition of the levator muscle and the extent of ptosis. After we examine you, we will discuss the findings together with you and plan the further procedure for you (or your child).
If the function of the levator muscle is still relatively intact, we will suggest what’s called levator resection: the levator muscle is shortened and strengthened. We do this by making a cut in the eyelid crease, then shortening the levator muscle by a predetermined and precisely defined length. The incision is later closed with self-dissolving stitches, and the entire operation is performed under general anaesthesia
If the function of the levator muscle is weak, we typically perform what’s called frontalis suspension surgery. The surgeon places a sling under the muscle and connects it with the eyebrow. This loop is inserted through small, approximately 5 mm-long punctures over the eyebrows and in the upper lid area. This sling is then tightened until the position of the upper lid reaches the desired height. The punctures on the eyebrows are closed with self-resecting sutures – those in the eyelid heal without suture. The operation is performed under general anaesthesia.
When to operate?
If the ptosis is mild and the eye is not in danger of developing amblyopia, the operation can be postponed, and we will monitor the situation before intervening. However, we would suggest that the operation be considered at the onset of puberty, in order to relieve the psychological pressure on your child that other children might place on your child.
However, if your child’s vision is at risk, early surgery is needed to support normal vision and prevent amblyopia.
The “perfect” symmetry
We aim for perfection, but it’s important to realize that in about 15% of cases where we’ve operated on one or two eyelids, we might have a good result, but thanks to the healing processes potentially changing lid height, the patient might still end up with a small asymmetry between the eyelid opening height of both eyes. Having said that, these small differences are natural – many people have this, and this should be tolerated, especially because the final lid height is only stable after about 6 months after surgery – until then, it might appear that there is under- or over-correction. If there is still a clear difference after 6 months (> 2mm), then, if appropriate, we will suggest a re-operation.
In acquired ptosis in adulthood, the levator muscle functions normally and “only” needs to be raised to the correct height. In children with congenital ptosis, the eyelid muscle doesn’t work sufficiently well enough to lift the eyelid completely. Raising the muscle alone is not enough: the muscle must be shortened. This results in a normal-looking eyelid height when looking straight ahead, but the upper eyelid “stops” moving below that level when looking down. This is called “lid lag” and unavoidable – but your child will learn to compensate for this after surgery so that the lid lag is not too noticeable.