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]
The congenital problems that can affect the nasolacrimal system are outlined below.
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]
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.
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.
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.
Atresia or failure of canalization of the lacrimal canaliculi may occur in conjunction with punctal atresia.
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]
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]
Congenital nasolacrimal anomalies, particularly obstruction, can lead to various clinical manifestations, including the following:
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]
No quoted difference in racial incidence of congenital nasolacrimal system abnormalities exists.
No sexual difference exists.
Nasolacrimal obstruction occurs in 2-4% of newborns.
Overall prognosis is excellent. More than 90% of children with these developmental anomalies have improved subjective tearing postoperatively.
Patient history should include the following:
A complete ophthalmic assessment must be performed. A dye disappearance test is probably the single most useful test. Place a drop of fluorescein in each eye, and monitor with a cobalt blue light; if a pool is still present after 5 minutes, the test is positive, and the baby likely has some type of obstruction in the nasolacrimal system.
Palpating the lacrimal sac may result in tears and/or mucoid discharge refluxing onto the eye through the puncta.
Measure corneal diameter, and, if suspicious, consider performing an intraocular pressure measurement. (See Glaucoma, Primary Congenital.)
Usually, these anomalies are sporadic, but genetics, prematurity, and maternal drug use can be possible influencing factors.
Ocular abnormalities are present in 20% of patients, and systemic abnormalities are present in almost 25% of patients with serious congenital nasolacrimal duct anomalies.
Neonatal dacryocystocele
Approximately 3% of infants with NLDO present in the neonatal period with a dacryocystocele. Dacryocystoceles are clinically important for two reasons. First, if the nasolacrimal duct cysts are large, they may cause respiratory problems in newborns. The second important clinical problem in these patients is the potential for acute lacrimal infection. Because infants are relatively immunocompromised in the first few months of life, these infections have the potential to spread, causing serious problems such as orbital cellulitis, meningitis, or sepsis. Prompt treatment of these infected dacryocystoceles is indicated.[8]
Imaging studies may include the following:
Other tests may include the following:
Punctal agenesis usually is associated with the absence of underlying canalicular tissue in 86% of cases in one series.
Congenital nasolacrimal duct obstructions spontaneously resolve in 90% of cases during the first year of life. Some physicians have advocated massage with digital pressure (Crigler's lacrimal sac compression) as an aid to speeding up this natural resolution.[10] Other than massage, topical antibiotics are useful for mucopurulent discharge, but the only treatment of efficacy for those patients who do not resolve spontaneously is surgery.
Probing cures 95% of congenital nasolacrimal obstructions. Prognosis for probing decreases exponentially with the increasing number of probings and the age of the patient. Rarely, it is successful after the third time or after 3 years.[11]
It has been advocated as an alternate procedure to dacryocystorhinostomy (DCR) in children who have failed probing.[12]
Success rates of 80-95% have been reported, but most patients have only been probed twice or less and are younger than 2 years. Prognosis is poor for those patients with previous dacryocystitis and for those patients in whom an obstruction is encountered during the procedure.
Lim et al noted that increasing the duration of intubation was not associated with increasing the chance of success but with a significantly higher risk for failure if longer than 18 months (P=0.03).[13] The retention of stents for longer than 12 months was associated with a significantly lower success rate (67%). The presence of Down syndrome, older age at the time of surgery, and sex of the patient were not predictive factors for treatment failure. The unplanned removal of the tubes because of dislodgement was the most common complication, occurring in 25% of eyes, but did not affect the functional outcome. Endoscopy guided probing and or intubation is a particularly effective treatment modality.[14]
This procedure has slightly better results than intubation alone. Most probing failures occur as a result of upper sac or mid duct obstructions and are not amenable to cure by instrumentation. Repeat probing procedures and intubation can cause serious complications, including false passages, canalicular scarring, and stenosis. Dacryoplasty is now being used as a primary procedure before even standard probing.[15] The AAO did a journal review in 2018 showing its excellent results.[16]
This treatment is the gold standard when a patent canalicular system is present.[17] See Nasolacrimal Duct, Obstruction.
If the upper system is scarred or otherwise not amenable to opening, then it can be bypassed using a prosthesis, such as a Lester-Jones tube. This procedure probably should be avoided until the child is older than 10 years because the prosthesis does require care from the patient and often has minor complications and revisions. In punctal agenesis where no canalicular tissue can be identified, the insertion of a Lester-Jones tube is necessary.
Consultations can include the following:
Bleeding: Serious bleeding is rare, occurring in only 1-2% of surgeries or postoperatively.
Surgical failures: In these complicated conditions, a 10% rate of failure occurs.
Wound infections: These occur in 5-10% of patients, usually as wound abscesses on the fourth postoperative day.
Silicone or polyethylene tubing complications: These complications occur in about 15% of cases and include the following: corneal abrasion, pyogenic granuloma, low-grade infection, chronic nasal irritation and congestion, epistaxis, sinusitis, and pharyngitis.
Bypass tube complications: These frequently occur in at least 40% of patients postoperatively and include tube loss or migration and tube obstruction.
Anesthesia complications: In children, these complications are more frequent due to drugs, blood loss, malignant hyperthermia, and pseudocholinesterase deficiency.
Patients should receive follow-up care as needed.
It has been demonstrated that anisometropic amblyopia can occur in 10% to 12% of children with CLNDO. Therefore, all cases undergo a thorough ophthalmic eye examination and cycloplegic refraction, followed by careful monitoring for three to four years.[18]