Nasolacrimal obstruction, infection and DCR

Congenital Nasolacrimal Duct Obstruction (CNLDO)

Congenital Nasolacrimal Duct Obstruction (CNLDO) is the most frequent cause of persistent tearing and mattering in infants, affecting approximately $5-20\%$ of newborns.

Etiology & Clinical Presentation

• Pathogenesis: Caused by failure of complete canalisation of the distal nasolacrimal duct, resulting in persistent membranous occlusion of the Valve of Hasner at the inferior meatal ostium.
• Clinical Presentation: Onset within the first 2 to 4 weeks of life (coinciding with the maturation of reflex tear production). Manifests as persistent unilateral or bilateral epiphora, crusting of eyelid margins, and mucopurulent discharge that mats the eyelashes upon awakening. Slit-lamp exam reveals an elevated tear meniscus, pooling of tears, and expressible reflux from the puncta upon digital pressure over the sac.
• Differential Diagnosis: Must be differentiated from ophthalmia neonatorum (conjunctival injection is prominent; absent in uncomplicated CNLDO) and congenital glaucoma (hallmarked by corneal enlargement, corneal oedema, photophobia, blepharospasm, and elevated IOP).

Natural History & Stepwise Management Strategy

1. Conservative Management of Uncomplicated Congenital Obstruction:
   • Many uncomplicated congenital obstructions resolve during infancy. Resolution probability changes with age and case definition; persistent symptoms, infection and dacryocele require individual assessment.
   • Crigler Hydrostatic Massage: The parent places an index finger over the common canaliculus (occluding the puncta to prevent reflux) and strokes firmly downward over the lacrimal sac toward the nose. This generates elevated hydrostatic pressure within the closed sac and duct, popping open the membranous obstruction at the Valve of Hasner. Performed 3-4 times daily.
   • Topical antibiotics (e.g. tobramycin, chloramphenicol) are prescribed only intermittently during acute purulent flare-ups to control discharge; they do not resolve the anatomical block.
2. Lacrimal Probing:
   • Timing: Discuss probing for persistent obstruction according to age, severity, spontaneous-resolution probability and local paediatric practice. Infection, dacryocele or airway symptoms can require earlier intervention; uncomplicated cases do not share a compulsory age cutoff.
   • Technique: A Bowman probe (size 00 or 0) is introduced vertically for $2\text{ mm}$, turned horizontally into the sac (hard stop against lacrimal bone), rotated $90^\circ$ downward, and advanced through the nasolacrimal canal into the inferior meatus, piercing the membrane at the Valve of Hasner. A metal-on-metal "click" confirms entry into the meatus.
   • Outcome: Primary probing is often effective, but success depends on age, obstruction complexity, prior treatment and the outcome definition. Persistent symptoms require reassessment rather than reliance on a universal percentage.
3. Refractory Interventions:
   • Silicone Intubation (Crawford / Ritleng Tubes): Indicated for failed primary probing, severe canalicular stenosis, or complex ductal obstruction. Stents are left in situ for 3 to 6 months.
   • Balloon Dacryoplasty: High-pressure balloon catheter dilation of the duct.
   • Dacryocystorhinostomy (DCR): Reserved for persistent obstruction beyond age 2-3 years, failed intubations, or underlying bony craniofacial anomalies.

Congenital Dacryocele (Amniotocele)

• Distension of the lacrimal sac present at birth caused by concurrent distal obstruction at the Valve of Hasner and proximal one-way valve entrapment at the Valve of Rosenmüller.
• Presents as a bluish, tense, cystic swelling inferior to the medial canthal tendon. Intranasal extension can cause respiratory distress in obligate nasal-breathing neonates. Carries a high risk of developing acute dacryocystitis; requires early probing if conservative warm compresses and massage fail to decompress the cyst within days.

Dacryocystitis & Dacryocystorhinostomy (DCR)

Dacryocystitis is an infection and inflammation of the lacrimal sac, almost universally arising secondary to complete nasolacrimal duct obstruction (NLDO).

Acute Dacryocystitis

• Clinical Presentation: Rapid onset of intense, throbbing medial canthal pain, marked erythema, tenderness, and a warm, fluctuant swelling centered below the medial canthal tendon (corresponding to the anatomic position of the lacrimal sac). May be accompanied by systemic fever, leukocytosis, and secondary preseptal or orbital cellulitis.
• Microbiology: Gram-positive cocci (Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes) and Gram-negative organisms (Pseudomonas aeruginosa, Haemophilus influenzae).
• Medical Management: Urgent administration of oral or parenteral broad-spectrum antibiotics (e.g. co-amoxiclav, cefuroxime), warm compresses, and systemic analgesia.

Chronic Dacryocystitis

• Presents as persistent epiphora, recurrent unilateral conjunctivitis, and a painless or non-tender swelling at the medial canthus (lacrimal sac mucocele; dacryops instead describes a lacrimal-gland duct cyst).
• Digital pressure over the sac elicits copious regurgitation of thick, white mucopurulent discharge from the puncta.

Dacryocystorhinostomy (DCR): External vs. Endonasal Endoscopic

DCR is the surgical creation of an epithelialized, low-resistance bypass fistula between the lacrimal sac and the middle nasal meatus, bypassing an obstructed nasolacrimal duct:

1. External DCR (Dupuy-Dutemps / Toti Technique):
   • Incision: A straight or curvilinear cutaneous incision ($10-12\text{ mm}$) placed $8-10\text{ mm}$ medial to the inner canthus (avoiding the angular vein and artery).
   • Osteotomy: Periosteum is elevated from the anterior lacrimal crest, mobilizing the lacrimal sac. A bony window ($10-15\text{ mm}$ diameter) is resected through the thick anterior lacrimal crest (maxilla) and thin posterior lacrimal bone using rongeurs or a surgical drill, exposing the nasal mucosa of the middle meatus.
   • Mucosal Anastomosis: Longitudinal H-shaped incisions are made into both the lacrimal sac and nasal mucosa, creating anterior and posterior flaps. Posterior flaps are sutured; silicone intubation is selected according to the anatomy and operative plan; anterior flaps are meticulously sutured together to establish an epithelialized tunnel.
   • Outcomes: External DCR is well established. Assess both drainage patency and symptom relief; success depends on obstruction level, technique, revision status and follow-up.
2. Endonasal Endoscopic DCR:
   • Performed entirely through the nasal cavity under rigid endoscopic visualization without external skin incisions.
   • Technique: Nasal mucosal flap elevated anterior to the middle turbinate; osteotomy performed using Kerrison rongeurs, drills, or piezosurgery; medial wall of the lacrimal sac identified by transillumination using an endo-illuminator in the canaliculus; medial sac wall is completely marsupialized into the nasal cavity, with silicone intubation when indicated.
   • Advantages: Completely avoids a facial cutaneous scar; preserves the orbicularis lacrimal pump mechanism; allows simultaneous correction of intranasal pathology (deviated nasal septum, concha bullosa, synechiae); permits management of associated nasal disease. Modern outcomes can be comparable to external DCR, but depend on anatomy, technique and the definition of success.

Canaliculitis and Centurion syndrome

Canaliculitis is infection/inflammation within a canaliculus, often overlooked as recurrent unilateral conjunctivitis. A pouting punctum, focal canalicular tenderness and expressible mucopurulent discharge or concretions should prompt direct examination. A patent distal system on syringing does not rule it out: retained material can harbour infection while fluid still passes. Actinomyces is a classic organism, but other bacteria and mixed flora occur. Send discharge and removed concretions for appropriate microbiology; histology may reveal filamentous organisms. Ask about previous intracanalicular plugs or instrumentation as possible secondary causes.

Antimicrobials alone may fail when concretions remain. Selected punctum-sparing removal or canaliculotomy with curettage clears the reservoir, followed by organism-directed treatment and assessment for scarring. Choose the approach to preserve drainage function; there is no compulsory DCR for disease confined to a canaliculus. The primary surgical series illustrates the importance of complete concretion removal rather than treating only conjunctival discharge.

Centurion syndrome describes epiphora associated with anterior displacement of the medial lid/punctum, often with a prominent nasal bridge and altered medial canthal attachment. The punctum may fail to sit in the tear lake despite a patent duct. Examine lid apposition during blinking, punctal position and nasal anatomy, then distinguish malposition from stenosis and reflex tearing. Specialist correction addresses the anatomical pump/apposition problem; bypassing a normal duct does not by itself restore punctal contact. See the primary punctal-malposition report.

In a tearing patient with a normal irrigation test, ask whether the punctum collects tears and whether focal canalicular discharge or concretions are present. These two questions distinguish a mechanical intake problem from an infected reservoir and prevent an indiscriminate nasolacrimal operation.