A “droopy” or “lazy” eyelid is called ptosis. Older adults develop ptosis as part of the aging process because the tissues that hold up the eyelid stretch over time. Babies are born with ptosis because the muscle that lifts the lid did not develop properly. Pediatric ptosis can also have a neurologic basis. It is important to distinguish congenital (“myogenic”, muscular) ptosis from that caused by a neurological problem.

Apart from “looking different,” the medical risk of pediatric ptosis is permanent vision loss that can result when the lid covers the eye, preventing the brain from receiving information from that eye. Such vision loss is called amblyopia. While amblyopia can be reversed until 12 years of age, the underlying cause needs to be addressed. In other cases of ptosis, when the pupil is NOT completely covered, the ptosis can also cause significant astigmatism by pressing on the cornea. Finally, some babies with ptosis place their chin upwards (torticollis) as soon as they are capable of holding their own neck. This allows them to peek under the lid and use both eyes. When ptosis causes amblyopia, high astigmatism and/or a chin-up head position, timely surgery is indicated and any amblyopia present needs to be treated.

Congenital Ptosis
Congenital ptosis occurs because of abnormal development of the muscle and connective tissue that lift the eyelid. This can be associated with certain syndromes but usually is not. One of the hallmarks of congenital ptosis is the affected lid does not come all the way down when the eyes are looking down; the ptotic lid “lags” behind the normal lid (lid lag). Another characteristic is a relatively smooth lid with poor formation of the upper eyelid crease.

Neurologic Ptosis
All muscles in the body do as they are told by their nerve supply. Naturally, this applies to the muscles that rotate the eye (extraocular muscles) and those that lift the eyelid (levator and Muller muscles). If a neurologic problem affects the nerve supply of the levator – and ptosis results – this can be accompanied by abnormal function of the pupil and some of the extraocular muscles.

In addition to nerve impairment causing ptosis, there can be chemical abnormalities at the junction between the nerve and the muscle (myasthenia gravis). Myasthenia gravis is rare in childhood but needs to be considered.

Timing of surgery
Ptosis can cause amblyopia if the lid completely covers the pupil. In these cases, the ptosis must be repaired as soon as possible to prevent worsening of amblyopia and allow for its treatment. Another
indication for surgery is if the ptosis is causing high astigmatism (which can also produce amblyopia). Finally, if a child is lifting her chin all of the time she should have her ptosis repaired without significant delay. The abnormal head position (torticollis) is assumed so that she can use both eyes together and see things three-dimensionally.

If the ptosis is not severe enough to cause amblyopia there is nothing wrong with waiting until a child is 4 or 5 years old before surgery. Children younger than this don’t usually notice their appearance as different and are unlikely to be teased by other children. That said, some parents want earlier surgery and this is often a reasonable option.