Ptosis (pronounced “toe-sis”) refers to a drooping of the upper eyelid. Ptosis may be only partial whereby the droop is slight usually not obscuring the line of vision or total whereby vision is obstructed. Ptosis which is present at birth is called congenital ptosis. That which occurs later in life is called acquired ptosis. Ptosis can occur in isolation or could be a clinical feature of a systemic condition.
Congenital ptosis is most often due to an under-development of the eyelid lifting muscle (the levator). Although usually occurring as an isolated problem, children born with ptosis may also have eye movement abnormalities, muscular diseases, lid tumors or neurological disorders.
Children with ptosis often tilt their heads back into a chin-up posture to see or raise their eyebrows in an effort to raise their lids. If the lid droop affects both eyes, the child’s visual and motor development may be affected. The child may bump into things and may have difficulty walking.
If the lid covers a part of the visual axis, the child’s visual development can be affected which could lead to amblyopia (lazy eye). This usually occurs in a child when the lid is drooping severely enough to block vision or cause astigmatism. If not treated early in childhood, the child’s vision will be permanently reduced as a result.
In determining whether surgery is advisable, a detailed assessment is made by an ophthalmologist specialized in treating droopy eyelids. The age of the child, the severity of the ptosis and whether one or both eyelids are involved are factors taken into consideration. Measurement of the lid height, evaluation of the eyelids lifting and closing muscle strength and observation of the eye movements determine which surgical procedure is more appropriate.
The most common procedure involves advancing the under-developed levator muscle or suspending the lids to the brow (brow suspension) while the child is under general anesthesia.
Adult ptosis is commonly due to a weakening of the attachments between the levator muscle and the lid. Typically, this is a result of the aging process. Occasionally, ptosis can occur following cataract surgery or a traumatic injury. Adult ptosis may also occur as a complication of other diseases involving the levator muscle or its nerve supply such as diabetes or myasthenia gravis. An eyelid tumor may also cause a mechanical effect resulting in a ptosis.
Usually the patient notices a droopy lid and may complain of tiredness towards the end of the day. If the line of vision is blocked, the vision may be affected and the patient may adopt a head tilt up position to see.
Treatment when necessary is usually surgical and is done as an outpatient under local anesthesia. Performing the surgery under local anesthesia has the advantage of giving the surgeon a better idea as to how much to raise the eye lid so that a more balanced outcome is achieved.
There is usually some mild lid swelling post operatively which settles over the first 2 weeks. Post operative complications such as bleeding and infection are rare. Patients on aspirin, non-steroidal anti inflammatory drugs and blood thinning medication may have to temporarily discontinue their medication a few days prior and post surgery to reduce the chance of bleeding and bruising. Under or over correction can occasionally occur and if obvious, a suture adjustment may be required in the first to two weeks.
Patients with ptosis are generally pleased to have the visual obstruction removed in addition to having a better cosmetic appearance.