Ptosis is the medical term for drooping of the upper eyelid. It is most common in older people, although it can occur as a congenital or birth defect, or as a result of an eye injury or disease.

The most obvious sign of ptosis is drooping of the upper eyelids. This can be in just one eye, or it may affect both eyes.

Depending on how severely the lid droops, people with ptosis may have difficulty keeping their eyes open, may feel eye strain and eyebrow ache from the increased effort to raise the lids, or fatigue when reading.

At its most severe, ptosis can obstruct one’s vision as the upper eyelid sags so much that it begins to cover the pupil. Many people with severe ptosis find themselves tilting their heads backwards to see from under the eyelid. Ptosis generally gives the face a tired or severe appearance.

What causes ptosis?
Ageing

The most common cause of ptosis is the stretching of the levator muscle due to ageing. As the muscles around the eyes weaken, the upper eyelids may begin to droop.

Illustration: Drooping eyelids causing the typical tired look and raised eyebrows

Congenital ptosis

Ptosis which is present at birth is called congenital ptosis. This is usually a result of improper development of the levator muscle which lifts the upper eyelid.

  
Illustration: Congenital ptosis

Children with ptosis often tilt their heads or lift their eyebrows frequently to see properly.

Eye injury, trauma or disease

Sometimes, an eye trauma, injury or disease can cause ptosis. Generally, this occurs when there is either damage to the levator muscles that hold the eyelids up, or damage to the nerves which control these muscles.

  
Illustration: Congenital ptosis

It is also not uncommon to develop ptosis after cataract surgery or after contact lens wear. Other causes of ptosis include third cranial nerve palsy and neurological muscular disorders such as myasthenia and muscle dystrophies.

The type of treatment required depends on the cause of ptosis. Surgery is usually the recommended treatment for drooping eyelids.

The surgery is performed by an ophthalmologist on an outpatient basis, usually under a local anaesthetic.

The main goal of surgery is to elevate the upper eyelid to permit better vision and attempt to achieve a reasonable amount of symmetry. Good to excellent results can be achieved although perfect symmetry may not always be obtained.

For congenital ptosis, it is not always possible to achieve complete symmetry of both lid positions and function after surgery due to the abnormal function. Hence, patients may still have a drooping lid on up-gaze and the white of the eye (sclera) will become visible on down-gaze. There may also be inadequate lid closure during sleep. Congenital ptosis is usually repaired in childhood if it is severe and obstructs vision. If mild, it can be repaired either in later childhood or early adulthood

Ptosis in both children and adults can be treated with surgery to improve vision as well as cosmetic appearance. It is very important that children with ptosis have regular ophthalmic examinations early in life to protect them from the serious consequences of untreated amblyopia.