Can a congenital nasolacrimal duct obstruction become clinically apparent in an 18‑month‑old child?

Can Congenital Nasolacrimal Duct Obstruction Present at 18 Months?

Yes, congenital nasolacrimal duct obstruction (CNLDO) can absolutely still be present and clinically apparent at 18 months of age, though the majority of cases resolve spontaneously by 12 months. 1, 2

Natural History and Spontaneous Resolution

While CNLDO affects 5-20% of infants under 1 year, the condition demonstrates high rates of spontaneous resolution throughout the first year of life, with 80-90% resolving without surgical intervention by age 12 months 2, 3. However, this means that 10-20% of cases persist beyond the first birthday, making presentation at 18 months entirely consistent with CNLDO 1.

The key clinical point: spontaneous resolution continues to occur even after 12 months of age, though at decreasing rates 2. One study documented that 66% of eyes randomized to observation had resolved by 6 months after initial presentation, leaving 34% still obstructed 4.

Clinical Presentation at 18 Months

At this age, you should look for:

• Excessive tearing (epiphora) that persists or worsens with upper respiratory infections 1
• Mucoid or purulent discharge from the medial canthus, particularly upon waking 5
• Conjunctival injection suggesting secondary bacterial conjunctivitis 5
• Matted eyelashes from chronic discharge 1
• History of recurrent conjunctivitis requiring multiple courses of topical antibiotics 1

Critical Red Flags Requiring Urgent Evaluation

Immediately evaluate for dacryocystitis if you observe: 5

• Pain, swelling, or erythema over the lacrimal sac area (medial to the medial canthus)
• Fever accompanying the above signs
• Corneal involvement or ulceration

These findings require urgent treatment and cannot be managed conservatively 5.

Management Algorithm at 18 Months

Step 1: Confirm Diagnosis

Perform fluorescein dye disappearance test to confirm nasolacrimal duct obstruction 3. The dye should normally clear within 5 minutes; persistence beyond this indicates obstruction.

Step 2: Assess Severity

• Mild symptoms (occasional tearing without infection): Consider continued observation with lacrimal sac massage 2, 3
• Moderate to severe symptoms (persistent discharge, recurrent conjunctivitis): Proceed to probing 2

Step 3: Treatment Decision

For persistent CNLDO at 18 months, nasolacrimal probing is the first-line interventional therapy 2. The evidence shows:

• Success rates for probing decrease with advancing age, making earlier intervention (once conservative management has failed) more effective than further delay 2
• Probing successfully addresses most obstructions in children over 1 year 1
• The optimal timing remains controversial, but persistent obstruction beyond 12 months with moderate-to-severe symptoms warrants probing rather than indefinite observation 2

Step 4: Adjunctive Medical Management

Only prescribe topical antibiotic drops when signs of secondary bacterial conjunctivitis develop (purulent discharge or conjunctival injection) 5. Do not use antibiotics prophylactically or continuously.

Common Clinical Pitfalls

Pitfall #1: Assuming all tearing at this age is CNLDO Consider alternative diagnoses including:

• Congenital glaucoma (look for photophobia, corneal clouding, enlarged cornea)
• Distichiasis or trichiasis (examine lash line carefully)
• Conjunctivitis from other causes

Pitfall #2: Delaying probing indefinitely While spontaneous resolution can occur after 12 months, the success rate of probing decreases with age 2. Balance the possibility of spontaneous resolution against decreasing surgical success rates when symptoms are moderate to severe.

Pitfall #3: Performing office-based probing without anesthesia at this age At 18 months, probing should be performed under general anesthesia in the operating room for patient safety and to ensure adequate visualization 4. Office-based probing without anesthesia is only appropriate in younger infants.

If Initial Probing Fails

If symptoms persist after initial probing (occurs in 9-13% of cases), consider: 1, 2

• Repeat probing
• Balloon catheter dilation
• Silicone tube intubation
• Dacryocystorhinostomy (for complex cases with bony obstruction) 6

Prognosis

Children with unilateral CNLDO who undergo immediate probing have better treatment success than those managed with prolonged observation (RR 1.41,95% CI 1.12-1.78) 4. The complication rate is low, with bleeding from the punctum occurring in approximately 20% of procedures but no serious adverse events reported 4.