Blepharoptosis, often shortened to ptosis (pronounced toe-sis), means droopy upper eyelid. Ptosis occurs when the muscles that lift the eyelid do not contract strongly enough, or when their tendons stretch over time, and lose the ability to lift the eyelid effectively. As a result, the eyelid margin—the edge where the lashes arise—sits lower than normal, making the eye opening appears smaller. Ptosis can affect one eye, both eyes, or one eye more than the other.
Most patients describe their eyelids as feeling heavy, tired, or lazy. Some notice shadowing or reduced upper peripheral vision. Others simply feel that they look tired, sleepy, or less engaged. Even before patients consciously notice these changes, many are already using their forehead muscles to lift their brows and thus their eyelids and compensate for the drooping eyelids. Over time, this compensation can lead first to dynamic forehead wrinkles and later to static forehead wrinkles. Dynamic wrinkles appear when muscles contract; static wrinkles remain visible even when the muscles are relaxed.
Ptosis occurs for several reasons. About 90% of cases are caused by thinning, stretching, or weakening of the eyelid retractor muscles and tendons. These muscles are called levator muscle and Müller muscle. This process is usually age-related and is often referred to as involutional or senile ptosis. As we age, we lose muscle tone throughout the body. Similarly, the millions of blinks we make over a lifetime can gradually thin and stretch the muscles and tendons in the eyelids. The thinner and more stretched these structures become, the less force they can generate to lift the eyelid.
A good analogy is the biceps muscle: a strong, firm biceps can generate more force than a thin, flabby one. In the same way, a stronger eyelid muscle lifts the lid better than one that has stretched and attenuated over time.
In younger patients, a common cause of tendon stretching is long-term contact lens wear. There are two main theories for how contact lenses may contribute to ptosis. First, repeated blinking over the edge of the contact lens may gradually stretch the muscle and tendon. This is particularly associated with rigid gas permeable lenses. Second, repeated manipulation of the eyelid when inserting and removing the lenses may do the same.
A less common cause of ptosis is trauma. Trauma can lead to ptosis either through direct injury to the eyelid muscle or through severe, prolonged swelling of the eyelid. In some cases, ptosis caused by swelling may be temporary and improve once the swelling resolves. In other cases, it may become permanent, especially if the eyelid structures are already mildly stretched or weakened before the injury. More broadly, any condition that causes significant eyelid swelling can affect the retractor muscles in a similar way. This type of ptosis is called mechanical ptosis.
Other less common causes include congenital and neurologic ptosis. Congenital ptosis occurs when the eyelid retractor muscles do not develop fully during gestation, so the drooping is present at birth. Neurologic ptosis results from disrupted signaling between the nerves and the eyelid muscles and may require further evaluation for an underlying systemic condition.
The good news is that most forms of ptosis can be corrected surgically by tightening either the Müller muscle or the levator muscle/tendon. If the droop is mild—typically 2 mm or less—and there is a good response to an alpha-agonist eye drop such as phenylephrine, the ptosis may be corrected by tightening the Müller muscle. If the ptosis is greater than 2 mm, if levator function is reduced, or if the response to phenylephrine is suboptimal, repair usually involves tightening the levator tendon or muscle.
In general, tightening of the Müller muscle—called a mullerectomy, conjunctiva-Müller muscle resection (CMMR), or Müller muscle-conjunctival resection (MMCR)—is used for milder cases of ptosis. This procedure is performed from the backside of the eyelid. The eyelid is everted, or flipped, to expose its inner surface. The Müller muscle is clamped, a suture is passed through it, and a segment of the muscle is excised. Removing a segment of the muscle shortens it, and shortening the muscle increases its ability to contract and produce force to lift the eyelid.
For more significant ptosis, levator advancement is necessary. This procedure involves making an incision in the eyelid crease and carefully dissecting through the tissues to identify the levator muscle and its tendon, known as the levator aponeurosis. The aponeurosis is detached and reattached to the tarsus, the firm supportive plate within the eyelid, using tighter tension. In more severe ptosis, the sutures may be placed higher into the levator muscle itself to achieve greater shortening and tightness. In very severe cases, a portion of the levator muscle may also be excised. The more the muscle is shortened, the tighter and more effective its lifting action becomes.
Of the two muscles, the levator is the primary muscle responsible for elevating the upper eyelid. The Müller muscle typically contributes about 2 mm of lift, while the remainder of eyelid elevation depends on the levator. For that reason, Müller muscle procedures are generally used for milder ptosis, while levator repair is used for more significant cases.
Like any age-related repair, ptosis surgery does not stop the aging process. Over time, the eyelid tissues can continue to stretch and weaken, and ptosis may recur. In many patients, surgery provides improvement for about 10 to 15 years, although this varies depending on baseline muscle function and tissue quality. For this reason, it is not unusual for patients to need a second ptosis repair later in life.
Nearly all of my patients are happy they chose ptosis repair. Restoring a more open, refreshed, and engaged appearance—and in many cases improving the superior visual field—makes the procedure well worth it.
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