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.

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.