Ptosis of the eyelid is the medical name for the drooping of the upper lid, which can happen in one or both eyes. A low upper lid can interfere with vision by affecting the top part of your visual field, causing difficulty in keeping your eyelids open, eyestrain or eyebrow ache (from the increased effort needed to raise your eyelids), fatigue, especially when reading, neck strain and, if low enough, reduce your visual acuity.
For some patients, ptosis poses a cosmetic problem too, especially if asymmetrical.
Ptosis can either be present at birth (congenital), or appear later in life (acquired), with some causes including long-term contact lens wear, trauma, post-surgery (including cataract) and as part of the ageing process. There are less common causes of a droopy eyelid, such as problems with the nerves or muscles.
What causes ptosis?
Acquired ptosis affects patient’s later in life and can be due to a defect in the muscles or nerves of the eyelid which can occur with simple ageing or injury. The commonest cause is slippage of the anchors of the eyelid lifting muscle and this is the most frequent type of ptosis.
Congenital ptosis affects a child from birth and is commonly due to a defect in the levator muscle which raises the eyelids. It can affect one or both lids. Although this can be purely a cosmetic problem, it can also prevent normal visual development, so surgery to correct the lid position is sometimes necessary.
A weakness in the eyelid muscles can occur in some rare muscle conditions such as myasthenia gravis or myotonic dystrophy. Paralysis of the nerves supplying the eyelid can cause it to droop as in a third nerve palsy (a type of stroke). The eyelid can also droop if weighed down by a large cyst or swelling.
The most common treatment for ptosis, once it becomes problematic in surgery, however all options will be discussed. The operation takes around 45 minutes per eyelid and is usually done as a local anaesthetic (with or without sedation) and as a day case procedure.