Normal Eyelid Position

The upper lid rests at or just below the upper limbus. The lower lid normally sits at the lower limbus. The palpebral aperture is the distance between the upper lid margin and the lower lid margin. The normal measurement is approximately 9 mm. The position of the upper lid is best quantified as the upper lid margin reflex distance ( MRD ₁ ). This measurement extends from the central corneal light reflex to the upper lid margin and is normally 4 to 5 mm ( Figure 8.1 ).

Measurement of the margin reflex distance (MRD) and the palpebral fissure. The MRD ₁ is 1 mm. Often an estimate will suffice, 1 to 2 mm, in this case. The MRD ₂ is 5 mm. The palpebral fissure is the sum of the MRD ₁ and the MRD ₂ .

The Upper Eyelid Retractors

The retractors open the upper eyelid. The retractors are:

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  The levator muscle

  
  
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  Müller’s muscle

  
  
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  The frontalis muscle

Functional or anatomic abnormalities in the levator muscle complex are the cause of most cases of ptosis.

The Levator Muscle

The levator muscle is the primary retractor of the upper eyelid. This skeletal muscle is responsible for voluntary elevation of the upper eyelid. Innervation to the levator muscle is via the superior division of the third cranial nerve (oculomotor nerve). The levator muscle originates at the orbital apex and extends forward inferior to the bone of the orbital roof ( Figure 8.2 ). At the orbital aperture, the levator is supported by Whitnall ’ s ligament (see Figure 2.22 ). As the levator muscle travels anteriorly, it becomes a fibrous aponeurosis that extends inferiorly into the eyelid to insert on the anterior aspect of the tarsal plate. The muscle fibers of the levator extend inferior to Whitnall’s ligament in most eyelids. The line where the fibrous aponeurosis merges into the muscle is a useful landmark for me in the anterior ptosis operation. I make my first attempt at correcting the eyelid height with the suture passed through this junction. This position often gives an appropriate eyelid height; more is said on that later. Fibrous extensions of the aponeurosis pass through the orbicularis muscle to create the upper eyelid skin crease ( Figure 8.3 ).

The levator complex: levator aponeurosis, Whitnall’s ligament, and levator muscle.

Cross section of the upper eyelid.

Whitnall’s ligament is an important anatomic landmark. The ligament extends from the fascia surrounding the lacrimal gland temporally to the trochlea medially. Whitnall’s ligament is usually easy to see intraoperatively as a strong white band of fibrous tissue. Generally, the tissue superior to the ligament is muscle and the tissue inferior to the ligament is aponeurosis, although variation exists among individuals. It has been suggested that Whitnall’s ligament serves as a pulley for the levator muscle. Although the levator muscle complex does not slide through the ligament, the concept of the ligament allowing the muscle to change direction is a helpful one.

As the levator aponeurosis travels from Whitnall’s ligament to the tarsus, it fans out to form the horns of the levator aponeurosis. The horns are the medial and lateral flared extensions of the aponeurosis inserting into the medial and lateral canthal regions. During operations on the levator, you see that the lateral horn of the aponeurosis is much thicker and stronger than the medial horn. The lateral horn is cut, or released, from the lateral orbital rim to improve the typical temporal flare of the upper eyelid retraction in thyroid eye disease.

Müller’s muscle is responsible for the involuntary upper eyelid elevation seen in the sympathetically innervated fight or flight phenomenon. The muscle is sandwiched between the conjunctiva posteriorly and the levator aponeurosis anteriorly. Müller’s muscle extends from the superior margin of the upper tarsal plate to where the levator aponeurosis fuses with the levator muscle (inferior to Whitnall’s ligament) (see Figure 8.3 ). A prominent surgical landmark on the surface of Müller’s muscle is the peripheral arcade, a vascular arcade extending across the muscle a few millimeters above the tarsal plate ( Figure 8.4 ; see also Figure 2.26 ). The loss of innervation to Müller’s muscle results in the mild ptosis associated with Horner syndrome.

The peripheral vascular arcade in Müller’s muscle. Note the line of the surgically disinserted levator aponeurosis.

The Frontalis Muscle

No doubt you have patients with drooping upper lids who lift their eyebrows to provide a tiny bit more upper eyelid elevation. The frontalis muscle lifts the brows and is a weak retractor of the upper eyelids ( Figure 8.5 ). The muscle is part of the galea aponeurotica of the scalp. Superiorly the frontalis becomes a fibrous aponeurosis that extends to the occipitalis muscle on the posterior surface of the skull. The point at which the frontalis muscle fuses with the aponeurosis superiorly is apparent because the forehead furrows seen with frontalis action stop at that point. Like the other muscles of facial expression, the frontalis muscle is innervated by a branch of the facial nerve, the temporal branch (also called the frontal branch ) (see Figure 2.32 ). Elevation of the eyebrows and prominent forehead furrows seen in a patient with ptosis tell you that the drooping lids are interfering with the patient’s vision. In some patients, a brow ache occurs with extended brow activity. The action of the frontalis muscle should be blocked with your thumb when making measurements of the eyelids ( Figure 8.6 ).

The frontalis muscle is a weak elevator of the eyelid.

Frontalis muscle influence on MRD ₁ measurement. When entering the examination room, I can see that the brows are very high. ( A ) The patient in normal gaze unconsciously lifting the eyebrows to clear the visual axis. ( B ) During a discussion the brows relax a bit and the ptosis becomes more noticeable. Note that the brows are still above normal position.

The Eyelid Vital Signs

The condition or health of the eyelid can be identified by measuring the eyelid vital signs :

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  Margin reflex distance (MRD)

  
  
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  Levator function

  
  
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  Skin crease height and depth

  
  
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  Amount of upper eyelid skin

We have already mentioned the MRD as a simple way to measure the height of the upper lid. The most practical measure of the strength of the levator muscle is the levator function. The levator function is defined as the excursion of the upper lid from extreme downgaze to extreme upgaze measured in millimeters. This movement is normally 15 mm. The upper eyelid skin crease is created by the pull of the levator aponeurosis on the skin. The skin crease height is the distance from the lid margin to the crease. This height varies among individuals but averages 6 to 8 mm for men and 8 to 10 mm for women at the highest point. The crease slopes both medially and laterally. A weak levator muscle creates less pull on the skin so that the crease is less distinct or weak. The skin measurement gives you an idea if saggy eyelid skin is actually extra skin or the result of a droopy eyebrow (or a bit of both). Read this paragraph again.

The vital signs give you the information that you need to know to classify and treat ptosis and manage the fullness of the skin fold. The following concepts are repeated several times in this chapter:

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  Simple congenital ptosis is associated with decreased levator function.

  
  
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  Involutional ptosis is associated with normal levator function.

  
  
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  If levator function is normal, a shortening of the aponeurosis/muscle works well to lift the upper lid (levator aponeurosis advancement [LAA] operation). In most cases, a resection of the conjunctiva and Müller’s muscle (CMMR) works also.

  
  
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  If the levator function is poor, the eyelid is surgically connected to the brow (frontalis sling operation). The action of the frontalis muscle lifts the upper eyelid.

The levator function is important. As you become experienced in taking care of patients with ptosis, you realize that asking “What is the levator function?” becomes the critical question in terms of diagnosis and the approach to ptosis repair ( Box 8.1 ). We discuss this further in the next section.

A Simplified System

There are many types of ptosis and many systems that classify the types ( Box 8.2 ). From a practical point of view, most patients have either simple congenital ptosis or involutional ptosis . Most of the children have simple congenital ptosis. Most of the older adults have involutional ptosis. I group the other less common types into the category unusual ptosis . This is an oversimplification, but it works well.

The Levator Function: The Relationship To Classification

For this approach to work, you must learn the common types of ptosis well. Most of our medical training is spent learning the details of diseases that we rarely see, an example being ptosis secondary to myasthenia gravis. For now, I emphasize the two common types of ptosis. After you know all about these two types, you are able to easily identify an unusual type of ptosis when you see something that does not fit with the two common types.

Levator function is the key concept in ptosis classification and treatment. We have already stated that levator function is defined as the movement, or excursion, of the eyelid from extreme downgaze to extreme upgaze. It is measured in millimeters, with 15 mm being the average normal adult measurement ( Figure 8.7 ). The levator function is the most clinically useful indicator of the health of the levator muscle. Normal movement suggests that the levator muscle has normal strength ( Box 8.3 ). As we have said, the levator function forms the basis of both the classification and treatment of ptosis. Does the patient have normal levator function? Is the levator function reduced? Is it poor or absent?

Measurement of the levator function. Note the position of the thumb on the brow, preventing any eyelid elevation by the frontalis muscle. ( A ) Eyelid in extreme downgaze. ( B ) Eyelid in extreme upgaze. The excursion of the eyelid, or levator function, is 15 mm in this case.

Simple congenital ptosis is always associated with reduced levator function. If you see a child with ptosis and normal levator function, something does not make sense, and you should consider another diagnosis. Involutional ptosis is associated with normal (or near normal function). If you see an adult with ptosis and reduced levator function, something does not make sense, and you should consider another diagnosis. Are you getting the idea? So far, we know that:

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  Simple congenital ptosis is associated with reduced levator function.

  
  
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  Involutional ptosis is associated with normal or near normal levator function.

  
  
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  Unusual types of ptosis are usually associated with reduced levator function, but levator function also can be normal.

When I see a patient with ptosis, I classify the ptosis into one of these three categories. Most patients have involutional or simple congenital ptosis. Congenital ptosis is much less common than the acquired forms of ptosis; consequently, the majority of patients you see have involutional ptosis. By definition, the children that you see do not have involutional ptosis (they are not old!). But you may see an adult that has had a simple congenital ptosis his or her whole life and is only seeking attention for it at this point.

Look at Figure 8.8 . A man in his 50 s presents with ptosis. The ptosis is severe and the function is reduced. This is not the typical involutional ptosis. In your history you ask how long the ptosis has been present, and he tells you it has been present since birth. Ah, the diagnosis is a simple congenital ptosis appearing in an adult. I hope that this simplified system is starting to become clear. As you get more experience it is even clearer. You walk into the room, and from across the room you see a middle-aged patient with severe ptosis and a weak or absent skin crease. That appearance tells you the levator function is poor. You think, this is not the typical involutional ptosis. Maybe he has some strange ptosis that is one of the many different unusual types of ptosis. You have yet to ask a question or touch the patient. Your first question is about how long the ptosis has been present. He tells you he has had it all his life. In the first few seconds, you have a presumptive diagnosis. Your further history and examination confirm the diagnosis of simple congenital ptosis.

Adult with bilateral ptosis, associated with reduced levator function (5 mm in the right eye and 7 mm in the left eye). Upon questioning you learn that the ptosis has been present all his life. Your examination shows a simple congenital ptosis, presenting for treatment in an adult.

A short diversion here: My goal throughout the book is to help you develop a logical system for diagnosing and treating disorders. Like everything in medicine, it does get easier with experience. The goal is understanding. Speed is not of the essence; accuracy is. You do things faster in the clinic and the operating room as you get experience. Learn to be accurate and technically excellent first.

Tips For Measuring The Margin Reflex Distance And Levator Function

Remember, your examination starts as you enter the examination room. Does your patient hold one or both eyebrows up? Are there lots of horizontal forehead wrinkles from chronic eyebrow elevation? Does your patient lift his or her chin up to see? As you start to ask questions, watch how the face changes as the patient relaxes. We can all lift our eyes open when we are alert or excited. You want to see how the patient looks without making an extra effort to open the eyes ( Figure 8.9 ).

( A ) Your patient’s level of alertness causes the eyelid height to vary considerably. This patient’s brows are always high to help eyelid elevation. ( B ) To accurately measure the MRD, push the eyebrows down into a relaxed position, so the frontalis muscle does not contribute to the eyelid elevation. Make sure the head is in a neutral position as you make the MRD measurements. With the eyebrows neutralized, the MRD ₁ is significantly lower. The visual axis is barely cleared. This is the amount of ptosis that you aim to fix. You can see why patients have more visual complaints in the evening after holding the eyebrows up all day.

Similarly, as you measure the levator function, you must immobilize the eyebrow so that the action of the frontalis muscle is eliminated completely. The amount of movement is measured with a millimeter ruler placed next to the patient’s eye. The measurement is straightforward with adults but may be difficult with children, who often elevate the chin as well as the eyes. It is sometimes helpful to practice a few times with the child before actually measuring the function. I often demonstrate on myself to give the child the idea. Using the example of a rocket ship blasting off helps to hold the child’s attention. Several measurements should be made until a reliable number can be obtained.

Watching how the lid crease develops with lid elevation gives a good idea of the function, as well. As you get experience with measuring levator excursion, you notice that the speed of elevation also varies among individuals. Later in the chapter, we talk more about how levator function plays a role in the treatment choice. At this point, we discuss simple congenital ptosis and involutional ptosis in detail.

Simple Congenital Ptosis

Let’s start with some comments on nomenclature . There are many ways to classify ptosis. Each has its own advantages. Some classification systems include congenital and acquired ptosis as the major categories. Obviously, congenital ptosis means that the patient was born with a drooping lid and acquired ptosis means that the ptosis developed after birth. Unfortunately, so many varied types of ptosis fit into these two categories that you are not given any direction for a treatment plan using this classification. To avoid confusion with the inclusive term congenital ptosis , I like to use the term simple congenital ptosis to describe a specific form of ptosis present at birth. For the most common form of acquired ptosis that occurs later in life, I like to use the term involutional ptosis ( Box 8.4 ).

In simple congenital ptosis, the eyelid is ptotic because of a dystrophy of the levator muscle itself. I use the term simple to specify that the only problem is the dystrophic levator muscle. Some forms of congenital ptosis have other eye or physical findings associated. In my classification system, these cases fall into the special category unusual ptosis. Often, the associated findings dictate the treatment. When you perform ptosis surgery on a patient with simple congenital ptosis, you see that the dystrophic muscle is infiltrated with fatty tissue. The muscle is no longer a healthy red color but is yellowish to a variable degree ( Figure 8.10 ). This weak muscle cannot move well so the levator function is reduced. Usually, the degree of ptosis is related to the levator function, that is, the lower the levator function, the more ptosis is present. In patients with severe ptosis, the levator function may be totally absent. In patients with mild ptosis, the levator function may be minimally reduced.

Fatty infiltration into the levator muscle seen in simple congenital ptosis.

As alluded to above, reduced levator function is associated with a weak or absent skin crease. Remember that the skin crease is formed by attachments of the levator aponeurosis extending through the orbicularis to the skin at or near the top of the tarsal plate. If the levator is not pulling well, the skin crease is likewise not as well defined.

Although we usually think of the upper lid as not moving up well, it is probably more accurate to think of the weak and fibrotic muscle not moving well in either upgaze or downgaze. A characteristic of congenital ptosis demonstrating this is known as lid lag on downgaze ( Figure 8.11 ). It is important to point this out to parents before repair because shortening of a fibrotic muscle decreases the already reduced eyelid movement in downgaze, so there is more lid lag.

Characteristics of simple congenital ptosis, in this case bilateral and asymmetric. ( A ) Ptotic right upper eyelid with a weak skin crease. ( B ) The upper eyelid does not drop as far on the less ptotic side (lid lag on downgaze) because of the fibrosis in the weak levator muscle. ( C ) The upper eyelid does not elevate well (reduced levator function).

Simple congenital ptosis ranges from mild to severe. In essentially all patients with congenital ptosis, the problem is bilateral. Sometimes, the amount of ptosis is quite asymmetric, and parents are only aware that one side droops (see Figure 8.11 ). It is worth pointing out the bilaterality because it often affects some of the subtleties of the treatment.

Typically, simple congenital ptosis is associated with:

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  Reduced levator function

  
  
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  A weak or absent skin crease

  
  
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  Lid lag on downgaze

We have stressed that levator function is the key to both classification and treatment of ptosis. For simple ptosis with levator function greater than 4 mm, a levator aponeurosis advancement (LAA) is the usual treatment. Greater amounts of advancement are necessary for diminishing amounts of function. With large advancements, all of the aponeurosis is resected and some levator muscle is advanced. Generally, this is still referred to as a levator aponeurosis advancement in this text, but more correctly it should be termed a levator muscle resection. If the levator function is less than 3 mm, a frontalis sling procedure is appropriate. For levator function between 3 and 4 mm, a generous advancement is usual, with the resection extending high above Whitnall’s ligament into the muscle itself ( Box 8.5 ). Some surgeons add an excision of 1 to 2 mm of tarsus to large muscle advancements. This has not been my practice, but there may be cases where this could be helpful. It would be unusual for me to use a CMMR for congenital ptosis, the exception being a very minimal ptosis. Again, there may be a few surgeons that have found success with this procedure for congenital ptosis, but I have not.

Involutional Ptosis

In contrast to simple congenital ptosis, involutional ptosis is associated with normal, or near normal, levator function . The traditional teaching says that the levator muscle is normal. It has been suggested that the droop of the eyelid is caused by the thinned aponeurosis stretching out or separating from the tarsal plate; hence, the commonly used name aponeurotic ptosis . The term disinsertion is used, implying a slipping of the aponeurosis (disinsertion) off the tarsal plate or a thinning of the aponeurosis (dehiscence or rarefaction) itself. This pathophysiologic concept is helpful to differentiate this form of ptosis from the simple congenital form in which the muscle is weakened and much less easy to tighten surgically.

From a conceptual point of view, these features are helpful. Remember the suggested pathogenesis is that the aponeurosis is disinserted or stretched. The muscle is normal. It then makes sense that the levator function is normal . A high skin crease is the result of the levator fibers to the skin being dragged upward with the disinserted aponeurosis. The lid margin remains low throughout downgaze: lid drop on downgaze . This is caused by the eyelid being longer because of the aponeurosis disinsertion or stretching. Contrast this with the lid lag on downgaze in congenital ptosis caused by the fibrotic levator muscle.

Later, I try to convince you that this theory of an aponeurotic etiology in most adult involutional ptosis cases is wrong. When you gain experience, you see that most cases of involutional ptosis have a normal aponeurosis and often resection of the entire aponeurosis is necessary to get a near normal eyelid position. However, when taking an examination, you should realize that you are now smarter than most question writers and you should answer that the aponeurosis is the cause of involutional ptosis! Read this paragraph again; the discussion continues in more detail later!

Involutional ptosis ranges from mild to severe . It may be bilateral or unilateral . Usually there is an element of bilaterality to the ptosis if you look for it, although the patient often only complains about the more ptotic side.

Typically, involutional ptosis is associated with:

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  Good levator function

  
  
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  A high skin crease

  
  
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  Lid drop on downgaze

Compare the photos of the patients with simple congenital and involutional ptosis ( Figure 8.12 ) to get these points clear in your mind. Although not all patients show these features on examination, the concept is valuable. Importantly, as we discuss later, the etiology of involutional ptosis as being entirely aponeurotic is likely not accurate.

Characteristics of involutional ptosis. ( A ) Ptotic left upper eyelid with a high skin crease. ( B ) The upper eyelid shows lid drop on downgaze. ( C ) The levator function is normal.

Because patients with involutional ptosis have normal levator function, tightening the levator aponeurosis is the procedure of choice. You should notice that, as long as the levator function is good, the LAA is the procedure of choice for both of the common types of ptosis.

Taking A History In Children With Ptosis

Is the diagnosis simple congenital ptosis? There are a few questions that you can ask to see if the child with ptosis has simple congenital ptosis. Remember that simple congenital ptosis involves only a ptotic upper lid in an otherwise healthy child with no other abnormal eye findings.

Is the ptosis congenital? When a ptosis is seen in a child, it is almost always congenital. Any onset after birth suggests a different diagnosis.

Is the ptosis unilateral or bilateral? Remember that congenital ptosis is usually bilateral but often asymmetric. The parents may not have recognized this. A severe unilateral congenital ptosis is at risk for amblyopia and is among the most difficult ptosis cases to treat.

Does the lid change position? Is the lid ever open all the way? Does the lid position change with eye movements? Does the eyelid position change with chewing or sucking? These findings change a suspected diagnosis of simple congenital ptosis to one of unusual ptosis; these cases are discussed in more detail soon. A diagnosis of simple congenital ptosis means that no other abnormalities are noted in the history or physical examination. You don’t need to know all the usual types at this point; just learn to recognize that there is some other associated problem.

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  Any ptosis is slightly worse when the patient is tired. Wide variations in the day are not typical of simple congenital ptosis.

  
  
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  Extreme variation of the lid position from moment to moment suggests a synkinetic form of ptosis. As the name suggests ( syn- , same; – kinesis , movement), these disorders include abnormal simultaneous movements of the lid and another muscle. Ptosis associated with abnormal lid movements caused by chewing, sucking, or other changes in jaw position is known as Marcus Gunn jaw winking. Ptosis associated with abnormal lid movements caused by changes in eye position is seen in third nerve palsy with aberrant regeneration.

Is there a family history of ptosis?

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  Strict inheritance of simple congenital ptosis is rare.

  
  
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  Occasionally, a family has several members with ptosis without any other associated abnormality.

  
  
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  More likely, a family history suggests the presence of blepharophimosis syndrome ( Figure 8.13A ), which consists of ptosis, epicanthus inversus, and telecanthus. The epicanthal folds and telecanthus are usually easy to recognize. The facies are usually a well-recognized family trait because of the autosomal dominant inheritance pattern. Often the parent bringing the child has the syndrome. Sporadic cases are not uncommon, however. Lower eyelid ectropion and abnormally shaped ears (lop ears) may also be present.

  
  

  
  

  
  

  

  
  

  
  

  History suggesting an unusual form of ptosis. ( A ) Family history of congenital ptosis, or blepharophimosis syndrome (see Figure 8.35 ). ( B ) Ptosis associated with Noonan syndrome (rare).

  
  
  
  
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  Congenital ptosis is not commonly associated with any ocular or systemic abnormalities. The dystrophy of the levator muscle is the only abnormality present. Rarely, a congenital ptosis may occur as part of a syndrome (see Figure 8.13B ). Usually, the presence of a syndrome is obvious, based upon physical or neurologic development, but questions about the child’s medical history are appropriate.

Taking A History In Adults With Ptosis

The goals of the history taking for an adult are the same as those for a child but are somewhat more involved because there are more unusual types of ptosis in adults. The factors that may modify the final height of the ptosis correction, such as dry eye, are often important.

The goals are to:

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  Determine the etiology of the ptosis

  
  
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  Identify any characteristics suggesting an unusual type of ptosis

  
  
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  Identify factors that modify the planned operation

  
  
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  In the adult, an additional piece of information to obtain is documentation of the effect of the ptosis on the patient’s vision.

Is the diagnosis involutional ptosis? The first part of the history taking helps you determine if the ptosis is the usual involutional type seen as the most common acquired ptosis in adults.

Is the ptosis acquired or has it been present since birth? When was the onset? What is the rate of progression?

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  Most adults have an acquired form of ptosis, usually the common involutional type. The onset is difficult to identify because the progression is usually so gradual over several years that no particular time can be identified as the exact onset.

  
  
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  An acute onset suggests a diagnosis other than involutional ptosis.

  
  
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  An exception to this is the onset of involutional ptosis after cataract surgery . This is uncommon today but occurred often when a superior rectus fixation suture was used in cataract surgery.

  
  
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  Occasionally an adult will have preexisting congenital ptosis that has slowly gotten worse over time or may have asymmetric congenital ptosis that can no longer be ignored because the normal side has progressively drooped more (see Figure 8.8 ). A review of old photos is rarely necessary because the physical examination usually confirms the reduced levator function of congenital ptosis.

  
  
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  Remember that any cause of ptosis in a child persists into adulthood.

The Margin Reflex Distance

We used the term margin reflex distance (MRD) earlier. The MRD is a useful measurement for describing the position of the eyelids. Before the introduction of the MRD, the palpebral fissure measurement was used. This distance is the millimeters measured between the upper and lower lids. A normal palpebral fissure is 9 to 10 mm. For the palpebral fissure measurement to be meaningful in describing the upper lid position, the lower lid must be in the normal position. A fissure of 9 mm could mean that the upper lid is crossing the pupil and that the lower lid is 4 mm below the lower limbus. For this reason, the palpebral fissure, or aperture, measurement has largely been replaced by the MRD measurement.

Useful refinements of the MRD measurement are the MRD ₁ and MRD ₂ . MRD ₁ designates the distance of the upper lid from the corneal light reflex. MRD ₂ designates the distance of the lower lid from the corneal light reflex. These measurements give a good mental picture and accurately define the position of the upper and lower lids.

The MRD ₁ measures the degree of ptosis. It should be measured using a penlight and a millimeter rule. With the patient at your eye level, ask him or her to look straight ahead at a distant target. Shine the penlight at the patient’s eye. The distance from the corneal light reflex to the upper lid margin, measured with the millimeter rule, is the MRD ₁ . With some experience, it is easy to estimate the MRD ₁ , if you assume that the corneal diameter is 10 mm and that the normal upper lid resting position is just below the upper limbus. The normal MRD ₁ is between 4 and 5 mm. If the lid margin crosses the pupil, the MRD ₁ is 0 mm. If the lid margin is about halfway down from the limbus to the corneal light reflex, the MRD ₁ is 2.5 mm (a good number to remember because an MRD ₁ of 2.0 or 2.5 is usually required by insurance companies as an indication that a visual impairment exists) ( Figure 8.15 ).

MRD and palpebral fissure measurements. Note that the palpebral fissures measure the same in examples A and D , although each represents a different clinical condition. ( A ) Normal: MRD ₁ of 4 mm, MRD ₂ of 5 mm, and palpebral fissure of 9 mm. ( B ) Upper lid ptosis: MRD ₁ of 2 mm, MRD ₂ of 5 mm, and palpebral fissure of 7 mm. ( C ) Upper lid retraction: MRD ₁ of 7 mm, MRD ₂ of 5 mm, and palpebral fissure of 12 mm. ( D ) Upper lid ptosis and lower lid retraction: MRD ₁ of 1 mm, MRD ₂ of 8 mm, and palpebral fissure of 9 mm.

It is important to remember that the patient should be relaxed during this measurement. The frontalis muscle should not be contributing to the lid opening. As we stated earlier, it is best to neutralize the brow during this measurement. Take care not to push the lid down, however. I usually ask the patient to close the eyes and then open them in a comfortable position. Often the patient is somewhat anxious during the initial part of the examination and the eyes are open more than usual. It is important to recognize this and help the patient relax during this measurement.

With experience, it is easy to accurately estimate the MRD just by watching the patient while obtaining the history. Although for the sake of organizing this textbook, I have separated history taking and physical examination, as you probably already know, many observational measurements are made while obtaining the history. As you have probably heard before in your training, the physical examination starts when the patient walks into the examination room. Let’s look at Figure 8.16 .

Bilateral severe ptosis in a patient with progressive muscular dystrophy. Very little facial movement is present. Without any conscious thought you surmise that this patient has an unusual ptosis. Her ptosis repair probably needs to be conservative to avoid corneal exposure.

As you begin the examination, you see a middle-aged woman who uses a walker. She has bilateral ptosis. Her face has very little expression; she is probably too young for Parkinson syndrome. There is almost no facial movement of either side and appears bilaterally symmetric. It is not a bilateral facial nerve paralysis (rare); there is no droop, and the face just barely moves. It looks like an unusual ptosis, probably myogenic. This is all determined in a moment of observation. I think you are getting the idea. It turns out that this patient has an unusual form of muscular dystrophy. She has reduced levator function, a poor Bell’s phenomenon, and a poor blink. You need to consider all this before you make a plan for ptosis repair. As you gain experience, it is surprising how quickly you pick up cues to help you make the diagnosis and refine your treatment plan.

The Skin Crease Height And Strength

The distance from the upper lid margin to the skin crease is the skin crease height. In adult women, the measurement is 8 to 10 mm, and in adult men, the measurement is 6 to 8 mm. In children, the height is somewhat less.

The skin crease is important for three reasons:

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  It tells you about the type of ptosis.

  
  
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  It gives you an estimate of the levator function.

  
  
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  It provides the standard incision line for opening the eyelid in most ptosis operations.

You see a weak, or indistinct, skin crease in simple congenital ptosis. The weaker the levator muscle is, the weaker the crease. Any patient with reduced levator function has a weakened skin crease. You see a formed crease in most patients with involutional ptosis. In many patients, the lid crease is higher on the more ptotic side. The standard ptosis operations begin with an incision in the skin crease. This incision gives you access to the levator aponeurosis and muscle. The wounds heal with minimal scarring.

In adults, the history and physical examination are followed by photographs and visual field testing. Upon return from visual field testing the technician puts Neo-Synephrine drops (2.5%) in one or both eyes. After a few minutes, I return to evaluate the effect of the drops and discuss options for treatment. More is presented on that later.

Amount Of Eyelid Skin

Removing some tissue from the skin fold, a blepharoplasty, is commonly done at the same time as a ptosis repair. We discussed the blepharoplasty procedure earlier, but as a reminder, the goals of a blepharoplasty are to:

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  Clear the visual axis of any skin hanging over the eyelid margin.

  
  
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  Provide an aesthetically pleasing appearance of the eyelid.

  
  
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  Adjust the tissue resection so that symmetric amounts of skin, muscle, and fat remain.

  
  
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  Make an appropriate symmetric skin crease formation.

  
  
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  Ensure that a brow ptosis is not part of the redundant-appearing eyelid fold.

To satisfy these goals, you need to know how much skin is present. The normal amount of eyelid skin varies among individuals. Generally, a well-tailored adult eyelid has 20 to 30 mm of skin between the eyelid margin and the junction of the eyelid and the brow skin. If a patient has a redundant-appearing eyelid fold but there is a normal amount of skin present, a brow ptosis is likely responsible, and your eyelid skin measurement helps to determine that. We discussed the upper blepharoplasty in detail in Chapter 6 if you need a review. Remember that at the end of any blepharoplasty procedure, there should be symmetric amounts of eyelid skin measuring 20 to 25 mm. Later in this chapter, in the pseudoptosis section, we look at a few refinements in blepharoplasty that help you achieve a symmetric eyelid appearance in complicated ptosis repairs.

Physical Examination of the Child With Ptosis

Is the diagnosis simple congenital ptosis? The levator function is reduced in simple congenital ptosis. There should be no other anatomic abnormalities present.

Measure the eyelid vital signs .

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  You probably see a bilateral, often asymmetric, ptosis. You likely have to estimate the MRD ₁ .

  
  
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  The levator function is reduced to some degree. The reduction in levator function is usually an indication of the amount of ptosis.

  
  
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  The skin crease is weakened, depending on the amount of levator function. If a child is difficult to examine, your best estimate of the levator function may be the depth of the crease.

  
  
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  The amount of eyelid skin is usually normal in children, but you have to pay special attention to the crease height and pretarsal show when operating to get a visually appealing result.

Measure the visual acuity . It may not be possible to measure the vision, but fixation should be steady and maintained. Any associated ocular abnormalities suggest the possibility of a syndrome.

Is the external appearance of the child normal?

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  The appearance should be normal in simple congenital ptosis.

  
  
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  The most common abnormal facies is seen in blepharophimosis syndrome.

  
  
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  Remember that many other syndromes can have ptosis as one of the associated findings.

Measure the motility .

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  Normal motility is associated with simple congenital ptosis.

  
  
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  The most common motility disturbance seen in children with ptosis is a localized weakness of the superior rectus muscle (said to occur in about 5% of patients born with ptosis).

  
  
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  Any bizarre movement of the upper lid associated with eye movement should suggest aberrant regeneration of the third nerve.

Ask the child to open and close the mouth and move the jaw around . No movement of the eyelid should occur with simple congenital ptosis. The presence of any lid movement leads to a diagnosis of Marcus Gunn jaw winking ptosis.

Physical Examination of the Adult With Ptosis

Is the diagnosis involutional ptosis? After the history taking in an adult, you suspect that this slowly progressive ptosis is the involutional type. During the physical examination, you confirm that the levator function is normal and that there are no other anatomic abnormalities present.

Measure the eyelid vital signs.

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  You probably see a bilateral, often asymmetric, ptosis. Accurately measure the MRD ₁ and MRD ₂ .

  
  
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  The levator function is normal; it should not be less than 12 to 13 mm. Watch the speed of the lid excursion. A slight reduction in lid speed should suggest a myogenic type of unusual ptosis.

  
  
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  The skin crease may be higher than normal.

  
  
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  There may or may not be extra eyelid skin present. The brow elevation may mask sagging skin. Make sure you estimate any degree of brow ptosis that may appear when the patient is not pulling the brows up to help clear the visual axis. Have the patient rest the brows and decide on the appropriate brow height, as well as eyelid opening.

Does the patient have a normal facial expression?

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  Weakness of the facial muscles is associated with the myogenic types of unusual ptosis.

  
  
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  Is there hyperkinetic movement of the face suggesting hemifacial spasm or aberrant regeneration of the facial nerve?

Measure the motility .

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  The eye movements should be normal for the patient’s age in involutional ptosis.

  
  
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  Any reduction in motility or symptoms of diplopia should suggest a diagnosis other than involutional ptosis. Conditions associated with types of unusual ptosis with decreased motility include myasthenia gravis, third nerve palsy, and chronic progressive external ophthalmoplegia (CPEO).

  
  
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  Any bizarre association of the upper lid position (ptosis or lid retraction) with eye movements should suggest aberrant regeneration of the third nerve.

Is the pupil normal? Are there signs of Horner syndrome? Do you see any miosis or lower lid elevation to suggest that a loss of sympathetic tone is responsible for the patient’s mild ptosis ( Horner syndrome includes upper lid ptosis, lower lid elevation, miosis , and anhidrosis of the ipsilateral side of the face )?

Neo-Synephrine Drops

As I stated earlier, moving toward a posterior approach for ptosis repair (CMMR) has been a big change for my practice. Using Neo-Synephrine drops in the evaluation and treatment of involutional ptosis is a helpful part of that change.

Neo-Synephrine 2.5% drops (let’s say neo drops) stimulate Müller’s muscle, which causes an eyelid elevation. Theoretically, the drop medically tightens the Müller’s muscle similar to what the CMMR operation does surgically. Many surgeons use the Neo-Synephrine test to see if a CMMR is the appropriate treatment ( Box 8.9 ). All surgeons do not agree that this test is important. The literature supports both points of view. I find using Neo-Synephrine drops very helpful in deciding if the patient is a candidate for a CMMR. The drop also helps me decide how much tissue to remove to get a normal postoperative eyelid height. There are other useful benefits, also.

Box 8.9

Phenylephrine (Neo-Synephrine) Drop Use: The Neo Test

CMMR

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  Is CMMR likely to be successful?

  
  
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  How much tissue to remove?

  
  
  
  
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    Small (6 mm), medium (8 mm), large (10 mm)

  
  

Hering’s law

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  What is the effect on the opposite upper eyelid?

  
  
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  Is bilateral surgery appropriate?

  
  
  
  
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    Will the patient appreciate the difference?

    
    
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    Does eyelid elevation crowd the skin fold?

  
  
  
  
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  Is a blepharoplasty or browplasty also important?

Let’s take the example of an involutional ptosis patient (symmetric MRD ₁ of 2 mm with levator function of 14 mm in both eyes). Once the ptosis patient has had photos taken and has returned from visual field testing, put a drop or two of Neo-Synephrine in each eye. After 5 minutes or so, look at the upper eyelid height. If the height is acceptable, I do a CMMR 8-mm resection. That is pretty simple. If the height is good but could be a bit more I resect 10 mm. If the height is too high (rare) I resect 6 mm. If there is a minimal response (unusual), I do an LAA. I have to admit that I don’t know if the drop test is necessary or that it is always 100% accurate, but for me, this technique works. I also have to admit that having a bit of an obsessive-compulsive disorder (like most of us) causes me to have a difficult time keeping it this simple. But it does work ( Figure 8.17 ).

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1. Clinical Anatomy
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3. Enucleation, Evisceration, Exenteration, and Care of the Eye Socket
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