This patient has a lacrimal sac fistula of the right eye.
Nasolacrimal duct obstruction is the most common nasolacrimal duct abnormality in children, but the presence of a draining ostium makes lacrimal sac fistula the likely diagnosis.
The presence of patent lacrimal puncta rules out the possibility of punctal atresia.
Congenital glaucoma, although a possible cause of excessive tearing and epiphora, is less likely given the normal intraocular pressure, presence of hyperopia, and normal optic nerves.
The long-standing nature of the patient's symptoms and lack of other symptoms makes infection, such as bacterial keratitis, unlikely.
The patient was referred to an oculoplastic specialist for evaluation. Because the patient was not significantly bothered by her symptoms, the parents elected to defer surgery to excise the fistula.
The nasolacrimal duct system comprises the superior and inferior canaliculi proximally and the lacrimal sac and nasolacrimal duct distally.[1,2] The lacrimal system develops in the sixth week of gestation, beginning as a cord of surface ectoderm that invaginates between the maxillary and frontonasal processes.[1,3,4] From this embryologic process, several congenital abnormalities of the nasolacrimal duct system can arise, most of which—other than nasolacrimal duct obstruction—are uncommon. Such abnormalities include dacryostenosis, sac diverticula, punctal atresia, and congenital lacrimal sac fistula.
A congenital lacrimal sac fistula is a lacrimal duct dysplasia in which ectopic epithelium from the lacrimal duct system connects to the skin or ends blindly in the subcutaneous tissue.[1,6] Fistulae can originate from anywhere along the duct system, including the canaliculi, lacrimal sac, or duct itself; most commonly, they are located between the skin and common canaliculus or lacrimal sac.[5,7] The fistula ostium is typically located inferolateral to the medial canthus.[1,2] In most patients, lacrimal sac fistulae are present unilaterally, but in rare cases these can be bilateral, especially in cases of familial inheritance or systemic association, such as Down syndrome.[2,8]
Lacrimal fistulae are uncommon, with a reported incidence of approximately 1 per 2000 births.[2,4,7,9] However, this incidence is disputed in the literature, with some investigators suggesting that the reported incidence is falsely high and others falsely low owing to reporting bias and referral bias.[4,9] They generally occur sporadically in the population, with both autosomal dominant and autosomal recessive inheritance patterns also being described in the literature.[2,7,9]
The pathogenesis of lacrimal fistulae is unknown, but they are probably caused by a defect in the invagination and transformation process of the ectoderm cord that forms the nasolacrimal duct system. This theory of pathogenesis is supported by the histopathologic analysis of excised fistulae, which shows stratified squamous epithelium similar to mature canaliculi.
Lacrimal fistulae are associated with several other clinical findings, one of the most prominent being Down syndrome but also including preauricular fistulae, hypospadias, and VACTERL syndrome (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities).[2,3,6,8,9]
Clinically, lacrimal sac fistulae can be symptomatic or asymptomatic. Asymptomatic cases can remain as such throughout life and thus are typically discovered on routine exam.[1,2] Symptomatic patients usually present with epiphora or mucopurulent discharge.[1,6] Patients with congenital fistulae may present with these symptoms several years after birth, because any small amount of drainage or discharge earlier in life may evaporate before becoming clinically significant. Rarely, patients may present with a history of recurrent dacryocystitis or infections of the lower lid due to the stasis within the tract or cavity, or a slowly growing cystic mass of the lower eyelid or medial canthus.[2,5,7,10]
The diagnosis can usually be made clinically by external inspection or by expression of mucoid secretions by pressing over the lacrimal sac. Sometimes, however, imaging or diagnostic procedures are used to confirm the diagnosis. Such techniques include probing of the ostium, CT, dacryocystography, dacryoendoscopy, and even use of impressionable polymers to form casts of the nasolacrimal system.[6,11]
Several treatment options are available to manage lacrimal fistulae. Asymptomatic patients are often observed. Symptomatic patients, such as those with mucoid discharge or epiphora, may undergo surgery. Owing to the limited number of surgical cases and clinical studies on lacrimal fistulae, recommended management is controversial.[7,9] Historically, electrocauterization of the external ostium and simple skin excision and closure were performed to alleviate systems, but these procedures often had poor success rates and thus are no longer recommended.[1,4,7]
The current literature shows fistulectomy to be a successful treatment option.[1,3] Fistulectomy can be performed as either an open or closed surgical procedure, and is often based on the characteristics of the patient and the comfort of the surgeon performing the procedure. Dacryocystorhinostomy or nasolacrimal intubation may also be performed to ensure the patency of the anatomical nasolacrimal duct system; this is especially important in cases where other nasolacrimal drainage abnormalities are present.[2,3,4,7]
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Cite this: Child With Increased Tearing in Right Eye - Medscape - Sep 06, 2017.