Evaluation of Tearing in Children

Fig. 26.1
Anatomy of lacrimal outflow system . Canaliculi are approximately 10 mm in length. A 2-mm vertical portion widens from punctum into an ampulla where it joints the horizontal canaliculus to enter the sac at the common canaliculus. These structures constitute the upper system. The sac and nasolacrimal duct constitute the lower system

From the puncta, tears travel into the canaliculi. The first part of each canaliculus is an approximately 2-mm vertical portion with an internal diameter of roughly 1 mm. At the base of the vertical section of canaliculus, there is a saccular dilation to 1.5–2 mm. This is termed the ampulla and signifies where the vertical canaliculus becomes horizontal.

The horizontal canaliculus is approximately 8 mm in length and arcs with the eyelid curve toward the medial canthus. The diameter of the horizontal canaliculus narrows to slightly less than 1 mm, although the elastic tissue that surrounds both the vertical and horizontal canaliculi allows for their dilation to several times their normal width.

The upper and lower canaliculi join in approximately 90% of people to form a common canaliculus or internal punctum. This joining occurs at an angle of roughly 25°. The common canaliculus continues for another 3–5 mm before emptying into the lacrimal sac . Just prior to joining the sac, there is frequently a small dilation in the common canaliculus, called the sinus of Maier. There are numerous infoldings that create a valve-like structure, known as the valve of Rosenmuller , at the opening of the common canaliculus into the lacrimal sac ; this valve prevents reflux of sac contents back into the canaliculi to exit onto the surface of the eye.

The common canaliculus empties into the lacrimal sac at the junction of the upper third and lower third of the sac. This occurs just posterior to the medial canthal tendon. Because the bulk of the sac lies below the medial canthal tendon, inflammatory and infectious sac processes commonly manifest as swellings below this structure. As will be discussed later in this chapter, this intimate relationship between the lacrimal sac and the medial canthal tendon is also important for the proper functioning of the lacrimal pump .

The sac can be arbitrarily divided into two parts: a fundus and a body. The fundus of the sac is that portion lying above the common canalicular opening and is 3–5 mm in length. The body is the remaining distal portion down to the entrance to the duct and is approximately 10 mm in length. The sac lies in the lacrimal fossa, a bony depression formed by the frontal process of the maxillary bone anteriorly and the lacrimal bone posteriorly. The fossa and sac are positioned anterior to the orbital septum and, thus, are preorbital not orbital structures.

Like the canaliculi and the nasolacrimal duct , the lacrimal sac is lined by pseudostratified ciliated columnar epithelium (e.g., respiratory epithelium) [3, 4]. The lacrimal sac is also richly invested with goblet cells whose mucous secretion may become important in nasolacrimal system obstructions.

The nasolacrimal system continues from the sac as a duct within the lateral wall of the nose. The interosseous portion of the duct is approximately 12 mm long and is directed inferiorly and slightly lateral and posterior. There are numerous constrictions within the duct that may often be felt on duct probing, but the most important infolding clinically is at the duct’s most distal end, termed the valve of Hasner . This fold of tissue is often the last part of the system to canalize [5]. The duct enters the nose under the inferior turbinate and within the inferior meatus. The meatal portion of the duct may be up to 5 mm long. There is some variation in exactly where within the inferior meatus the duct enters. Generally, the ostium for the duct is located anteriorly within the meatus, approximately 2.5 cm posterior to the naris.

It is convenient to divide the lacrimal system into two parts: an upper (proximal) system and a lower (distal) system. The upper system extends from the puncta through to including the common canaliculus. The lower system represents the sac through to the ostium of the duct in the inferior meatus. This anatomic division is useful in selecting management strategies for specific nasolacrimal drainage problems.

In children there can be variation in both the structures and relative measurements simply due to the system’s immaturity. These variations may contribute to the development of an obstruction or may become important if probing or more invasive lacrimal surgery is performed. During the first year of life, the distance from the punctum of either canaliculus to the floor of the nose is approximately 20 mm, whereas in adults this distance can range from 30 to 40 mm. In addition, the inferior meatus in children is flat and allows little space between the floor of the nose, the lateral nasal wall, and the inferior turbinate (Fig. 26.2). With age, this space increases. The lacrimal sac area is also less developed in children than in adults, a factor that can be important during dacryocystorhinostomy. The lacrimal crests are flat and poorly developed in small children, and the sac fossa is often shallow. Also, the relative compactness of the nose in some children sometimes leaves the ethmoidal air cells in an anterior location [6].


Fig. 26.2
Nasal fossa and sinuses . Coronal sections through nasal fossa and sinuses demonstrating sizes and relationships through various ages: (a) 2 months, (b) 1 year, (c) 5 years, and (d) 10 years (After Bernstein [19])

The Lacrimal Drainage Pump

Proper drainage of tears requires not only a patent nasolacrimal system but also a functioning tear pump (Fig. 26.3). A functioning tear pump requires a good working relationship between the lids, medial canthal tendon, and the sac. The process of tear drainage, then, is one that is dependent on the opening and closing of the lids.


Fig. 26.3
Lacrimal pump . (a) Anatomic relationships of medial canthal tendon and lacrimal sac. (b) Stages of lacrimal pump cycle with blinking

With lid closure, the superficial and deep heads of the pretarsal orbicularis muscle contract. These heads of the orbicularis surround the puncta and canaliculi. Contracture, therefore, closes the puncta and compresses and shortens the canaliculi in a horizontal manner. With lid closure, the deep head of the preseptal orbicularis also contracts. This part of the preseptal orbicularis is intimately related to the lacrimal sac fascia, and its contraction pulls on the sac, thereby expanding it. This expansion creates “negative pressure” or a drawing force within the sac, which pulls in tears from the compressed and shortened canaliculi. As the eyelid opens, the orbicularis relaxes. The natural elastic properties of the lacrimal sac cause it to collapse, and this forces the tears within the sac into the duct and down into the nose. As the orbicularis relaxes, the canaliculi return to their normal position and the puncta open. Capillary attraction then draws tears into the puncta and canaliculi, and the cycle repeats itself with the next blinking movement of the eyelids.


A thorough history is an essential part of any medical evaluation, and this is especially true when evaluating tearing in the pediatric patient. The exam is limited by virtue of the patient’s age and level of cooperation. Thus, in-office tests that are practical for adults, such as diagnostic irrigation and nasal evaluation, are not practical for most children. Nonetheless, a detailed history can provide a great deal of diagnostic information.

Obviously, the pediatric patient is not usually able to provide this detailed history, and the physician must turn to the child’s caretaker. It is important to obtain the history from the child’s primary caretaker—the person who is with the child when the tearing occurs and who can describe the symptoms. If the child is brought to the physician by someone other than the primary caretaker (a member of the extended family or a parent whose daily contact is limited, etc.), then efforts should be made to discuss the child’s symptoms with the person in closest contact with the child.

Children with a nasolacrimal system abnormality tend to have frequent symptoms. Tearing is the most associated symptom of a nasolacrimal system abnormality; however mattering of the eyelashes, mucoid or mucopurulent discharge, redness, and changes of the skin around the eyelids (due to stagnant tears and breakdown of superficial skin) are other frequently encountered problems. A child may exhibit one or more of these symptoms, and the physician should try to identify how the child manifests the problem and what is the daily chronology of events.

It is important to ascertain the frequency with which the symptoms are noted. Are the symptoms constant or intermittent? Have they increased or decreased in frequency? Are there any aggravating or relieving factors? For example, does the tearing occur only when the patient is outside in the cold or wind? Does a patient with crusting have epiphora only when in harsh environmental conditions? Likewise, is tearing noted or exacerbated only when the child has an upper respiratory infection? The answers to such questions can help to tell if the condition is improving on its own (as what happens in most instances of congenital nasolacrimal duct obstruction) and distinguish between patients with a complete obstruction and those with a stenosis that only intermittently obstructs. This also helps raise suspicions that the tearing is caused by allergy and not a true obstruction (as in a child who is fine except when outside in the spring or fall and who complains of itching or frequently rubs his/her eye).

The laterality of the symptoms should also be noted and correlated with any obvious facial abnormalities. Although up to two-thirds of congenitally impatent systems are unilateral [1, 7], a child with a facial or nose deformity and tearing on the same side may well have more than an imperforate duct ostium.

At what age did the symptoms first appear? A child’s tear production begins after the first few weeks of life [5, 8]; thus, truly congenitally impatent systems should manifest symptoms early. If the child was asymptomatic at first and developed symptoms after the first few months of life, then the problem is unlikely to be an impatent valve of Hasner . It is also useful to know if the child was full term and, if not, what his/her age adjusted for gestational dates is. With recent advances in neonatology, premature children have higher rates of survival. A child born at 30 weeks gestation who presents to your office with tearing 2 months after birth is really only 38 weeks gestational adjusted age. Since the nasolacrimal system is known to open at or shortly after birth in term infants [8], this child’s tearing is not to be unexpected and would allow for a longer trial of conservative management.

The occurrence of a precipitating event should be questioned. A child born with a bluish gray mass under the medial canthus or who developed a red, tense swelling in the canthal region will require different actions and may yield different clinical courses than a 2-month-old with crusting. Likewise, the history of trauma is essential because the possibility of canalicular or bony canal involvement portends different prognoses and therapeutic strategies.

Finally, in every evaluation of pediatric epiphora , it is essential to inquire about problems such as blepharospasm, eye rubbing, avoidance of light, or nystagmoid eye movements. A child with infantile glaucoma may present with similar symptoms, and misdiagnosis may lead to a visually devastating outcome. Therefore, it is important to perform a complete ophthalmologic evaluation on all children who present with tearing.

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Dec 19, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Evaluation of Tearing in Children

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