CHAPTER 19

Lacrimal Drainage System Abnormalities

Disorders of the lacrimal system, particularly nasolacrimal duct obstruction (NLDO), are among the most common problems encountered in pediatric ophthalmology. Symptoms of NLDO, most of which resolve spontaneously, develop in approximately 5% of infants. The pertinent anatomical features of the lacrimal drainage system and their development are discussed in BCSC Section 2,

Fundamentals and Principles of Ophthalmology, and Section 7, Orbit, Eyelids, and Lacrimal System.

One point about the evaluation of children with suspected lacrimal drainage system abnormalities deserves emphasis. While lacrimal obstruction occurs most often in patients aged 0–12 months, the presence of excessive tearing in such patients should always prompt the clinician to consider primary congenital (infantile) glaucoma. Tearing in an infant can be an important sign of this condition. Other signs and symptoms of glaucoma are photophobia, corneal clouding with or without enlargement, and breaks in Descemet membrane (see Chapter 22).

Congenital and Developmental Anomalies

Atresia of the Lacrimal Puncta or Canaliculi

Atresia of the lacrimal puncta or canaliculi refers to failure of canalization during development of the upper lacrimal system structures. Patients usually present with overflow of clear tears; there is no infection because bacteria cannot reach the lacrimal sac to produce one. If a patient with atresia of either the upper or lower canaliculus has symptoms that include mucopurulent discharge, this usually indicates concomitant obstruction of the distal NLD, with reflux of discharge through the normal canaliculus.

There are 2 main causes of upper lacrimal system obstruction. One is a thin membrane that obstructs the lacrimal puncta. The puncta otherwise appear normal. Simple puncture of the membrane with a punctal dilator eliminates this obstruction. For concomitant obstruction of the distal NLD, probing of the distal system is necessary. The second cause of upper lacrimal system obstruction is atresia of the puncta and canaliculi. In these patients, no puncta can be seen (Fig 19-1). If only 1 of the canaliculi is atretic and there is mucopurulent discharge, probing of the distal duct through the patent canaliculus may be curative. If both the upper and lower canaliculi are absent, an incision through the eyelid margin at the expected location of the canaliculi may reveal structures that can be cannulated. However, many patients ultimately require conjunctivodacryocystorhinostomy, which is usually deferred until they are older. Conjunctivodacryocystorhinostomy is discussed in BCSC Section 7,

Orbit, Eyelids, and Lacrimal System.

Figure 19-1 Atresia of the lacrimal puncta. No indentation is noted at the site of the normal punctal opening. (Reproduced with

permission from Lueder GT. Neonatal lacrimal system anomalies. Semin Ophthalmol. 1997;12(2):109.)

Congenital Lacrimal Fistula

A congenital lacrimal fistula is an epithelium-lined tract extending from the common canaliculus or lacrimal sac to the overlying skin surface. It usually presents as a small dimple medial to the eyelids, which may be difficult to detect in the absence of symptoms (Fig 19-2). If patients are asymptomatic, no treatment is necessary. Discharge from the fistula is often associated with distal NLDO and may cease after probing of the distal obstruction. If discharge persists despite a patent lacrimal duct, surgical excision of the fistula between the skin and normal lacrimal structures is required.

Figure 19-2 Lacrimal fistula. (Reproduced with permission from Lueder GT. Neonatal lacrimal system anomalies. Semin Ophthalmol. 1997;12(2):109.)

Dacryocystocele

Congenital dacryocystocele (dacryocele, mucocele, amniotocele) is present in approximately 3% of infants with NLDO. It develops when a distal blockage causes distention of the lacrimal sac. Kinking of the common canaliculus does not allow retrograde discharge of accumulated secretions, thereby preventing decompression of the lacrimal sac. Most patients with dacryocystoceles have associated cysts of the distal NLD, which may be seen beneath the inferior turbinate. Involvement is bilateral in 20%–30% of cases.

Clinical features

Dacryocystocele presents at birth or within the first few days of life as a bluish swelling just below and nasal to the medial canthus. The differential diagnosis includes hemangioma, dermoid cyst, and encephalocele. Hemangiomas are not typically present at birth. They have a vascular appearance and are generally less firm than dacryocystoceles. Dermoid cysts and encephaloceles present most often above the medial canthal tendon. The diagnosis is clinically apparent when a newborn has a nasal mass beneath the medial canthus that is associated with symptoms of NLDO (discussed later in the chapter). Imaging is usually not required in this case.

Dacryocystoceles are prone to infection, which differs in severity from the low-grade, chronic