Practice Essentials
The common abbreviations used for Congenital Nasolacrimal Duct Obstruction are CNLDO and for Complex Congenital Nasolacrimal Duct Obstruction C-CNLDO. Complex means not amenable to simple treatment. [1]
Background
The congenital problems that can affect the nasolacrimal system are outlined below.
Nasolacrimal duct obstruction (NLDO) or Dacryostenosis
A very common condition in which the extreme end of the nasolacrimal duct underneath the inferior turbinate fails to complete its canalization in the newborn period and may produce clinical symptoms in 6-20% of newborns. [2]
Absence of valves
The fold that is normally present at the end of the nasolacrimal duct or the valve of Hasner may be absent, in which case pneumatoceles of the sac may occur and nose blowing may cause retrograde passage of air. If the valve of Rosenmüller also is absent, it is possible to blow air from the nose into the eye, and nosebleeds may produce bloody tears.
Anomalies of the sac
Although diverticulum of the lacrimal sac may occur, a congenital fistula of the lacrimal sac, which has been termed lacrimal anlage duct by Jones, is more common.
Anomalies of the puncta
Congenital atresia, supernumerary or double puncta, and congenital slits of the puncta all may occur. Lateral displacement of the puncta may occur in some congenital syndromes, such as blepharophimosis.
Anomalies of the canaliculi
Atresia or failure of canalization of the lacrimal canaliculi may occur in conjunction with punctal atresia.
Pathophysiology
Canalization of the nasolacrimal duct system usually is complete by the eighth month of gestation; problems in this normal developmental process can cause any of the above anomalies. [3]
The lacrimal excretory system includes the puncta, canaliculi, common canaliculi, lacrimal sac, and nasolacrimal duct, which opens at the inferior meatus over a mucosal flap called the Hasner valve.
The most common causes of congenital nasolacrimal duct obstruction are as follows:
• Membranous persistence at the distal end of the nasolacrimal duct
• Bony abnormalities with associated narrow inferior bony nasolacrimal canal
• Stenosis of the inferior meatus [4]
Epidemiology
Frequency
United States
Nasolacrimal obstruction occurs in 2-4% of newborns. Of those patients with serious nasolacrimal obstruction (nonresponsive to 2 or more probing procedures, with or without intubation), 35% have nasolacrimal duct obstruction, 15% have punctal agenesis, 10% have congenital fistulas, and 5% have craniofacial defects.
International
Nasolacrimal obstruction occurs in 2-4% of newborns.
Premature infants have a higher incidence (16%) of CNLDO. [5]
Recent studies show the incidence of nasolacrimal obstruction in children with Down syndrome is likely between 22% [6] and 36%. [7]
Mortality/Morbidity
Congenital nasolacrimal anomalies, particularly obstruction, can lead to various clinical manifestations, including the following:
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Amniotocele: This condition occurs in neonates as a distention in the lacrimal sac. Amniotic fluid enters the sac, is retained by a nonpatent nasolacrimal duct, and is trapped in the sac by the valve at the common canaliculus, the valve of Rosenmüller. Probing the nasolacrimal duct as an office procedure usually is curative.
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Dacryocystitis (acute mucocele or pyocele): This condition exhibits acute distention and inflammation in the lacrimal sac region and may occur in the neonatal period. Probing is necessary in newborns with acute dacryocystitis to establish drainage as soon as possible. This procedure is performed with topical local anesthesia only.
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Tearing and mattering: Newborns who have congenital dacryostenosis may not develop acute dacryocystitis with a mucocele or pyocele of the sac in the early neonatal period but may simply have tearing with a chronic mucopurulent discharge, which usually manifests at 2 weeks. Topical antibiotics should be administered, and the parents must be instructed in the proper technique of lacrimal sac compression and massage. More than 90% of these cases clear and become asymptomatic with conservative management. Under normal circumstances, these children with mild-to-moderate symptoms of epiphora and lid crusting can be monitored for the first year of life without serious consequence or sequela. It is rarely necessary to make probing mandatory at an early age (eg, before 6 mo). A number of studies have confirmed that probing or silicone tube intubation in children after 12 months still has a very high success rate. These techniques are discussed in Treatment.
Risk Factors
Infants with an elevated risk for this condition include those with trisomy 21, ectrodactyly-ectodermal dysplasia-cleft lip/palate (EEC) syndrome, branchiooculofacial syndrome, CHARGE (coloboma, heart anomaly, choanal atresia, and retardation, genital and ear anomalies) syndrome, and Goldenhar syndrome. [2]
Race
No quoted difference in racial incidence of congenital nasolacrimal system abnormalities exists.
Sex
No sexual difference exists.
Age
Nasolacrimal obstruction occurs in 2-4% of newborns.
Prognosis
Overall prognosis is excellent. More than 90% of children with these developmental anomalies have improved subjective tearing postoperatively.
