Lifting the lid on a delicate problem
Eleven-year-old Andy Ho's mother was anxious about his upcoming admission to secondary school. But Ho (names changed for patient confidentiality reasons) had more reason than usual to worry about her son.
Andy's eyes were not the same as most other children. As an infant, he could not seem to open his eyes properly. It turned out that his eye muscles were too weak to fully open, so at age two, he underwent an operation to strengthen those weak eyelid muscles. But it made only a slight improvement to his right eye, keeping it slightly more open than the left.
The young boy was well aware of the differences in his appearance; he often avoided looking directly at others and was terribly shy. As he grew older, the condition took a toll on his social and emotional development.
While looking different may be difficult for a primary school pupil, secondary school presents its own heady and potentially crushing mixture of escalating peer pressure, increased need for social acceptance and belonging, as well as a growing awareness of the opposite sex. Andy's self-esteem could suffer even deeper trauma.
Ptosis, or drooping eyelid, is caused by weakness of the muscle responsible for raising the eyelid, damage to the nerves that control those muscles, or looseness of the skin of the upper eyelids.
Ho thought that the earlier failed attempt to correct the condition doomed Andy to suffer the rest of his life until her friends persuaded her to seek a second opinion, especially with the important milestone of secondary school looming. SheJ took the boy to see Dr Dorothy Fan Shu-ping and Dr Alvin Kwok Kwan-ho, consultant ophthalmologists with the Hong Kong Sanatorium and Hospital.
Fan explained that ptosis not only presented a cosmetic and emotional concern. In children younger than eight years old, the drooping eyelids could also result in vision problems and scramble the development of vision in their brains. It could cause astigmatism, and even amblyopia (also known as 'lazy eye') where the eyes are unable to see details properly. But treatment was available.
Kwok and Fan found that Andy's right eyelid muscle was stronger than the left. Hence, they could simply shorten and tighten the muscle in Andy's right eyelid to give it more 'spring' as the muscle is quite like a rubber band.
Andy's left eyelid muscle was much weaker, and a simple muscle strengthening procedure would not do the job. The doctors proposed using a sling operation or brow suspension, which would borrow the strength of the forehead muscle in keeping the eyelid open. The forehead muscle would be connected to the eyelid by using either the body's own tissue or a synthetic material.
Some patients have an extra tendon in the arm that can also be used for the brow suspension, but Andy didn't. The alternative was to take a tendon from his thigh. While using his own body tissue would reduce the chances of rejection, this option would create a second wound, increasing the patient's pain and risk of infection. His parents opted for him to use a synthetic material.
Synthetic material such as silicon carried a slightly higher risk of the body rejecting the material. But as the risk was not significant, the family was more comfortable with this option.
The trick in both procedures was to ensure that both eyes were able to close properly after the operation, failing which the eyes could suffer from dryness or be exposed to debris or contaminants, especially during sleep.
Andy's operation was successful. Although his eyes could not fully close in the days immediately after the operation, the function of his eyes grew more and more natural with time.
Six months after the operation, Ho reported that Andy was more sociable and confident.
In Andy's case, ptosis was a congenital abnormality. But Fan says the condition can affect adults, too, and can be a consequence of the ageing process, excess skin sagging over the eye or as a result of an injury or disease such as a stroke. Defects in the nerves that tell the eyelids to open, the muscle junctions that receive the nerve signals or the muscles in the eyelids can all prevent the eyelids from opening fully.
Some ptosis patients actually suffer from an autoimmune condition called myasthenia gravis. Such patients also suffer weakness in their voluntary muscles, which worsens when the patient is tired. Ptosis becomes more obvious then, as well.