Nasolacrimal duct obstruction (NLDO) is an obstruction of the nasolacrimal duct that typically occurs at the valve of Hasner. The incidence of NLDO is between 5 to 20% of newborns,1 and it is often a diagnosis of exclusion.
This article will guide you in the assessment, testing, and treatment of NLDO.
Assessing for NLDO
The NLDO diagnosis can often be made by taking a thorough history. Parents will report that the patient has had a teary eye with discharge for weeks to months that never seemed to fully go away.
They will report that the eye does not appear red, like a pink eye, but the skin around it may redden. Symptoms are always worse in the morning and when they are sick. They will state that the patient doesn’t seem bothered by it.
Figure 1: Slit lamp image of a pediatric patient with congenital NLDO; note the increase in the tear meniscus in the right eye.
Figure 1: Congenital Dacryoestenosis©Angel Nava-Castañeda, Y Levy Adriana Velasco. Image used under CC BY 4.0.
Physical examination guidelines for NLDO
When assessing for NLDO, it is important to look anatomically at the following structures:
- Puncta
- Punctal agenesis is the absence of a punctum. When evaluating a pediatric patient for NLDO, be sure to visualize the puncta.
- If they have punctal agenesis, there is no need to wait to refer to an oculoplastic surgeon for management and treatment.
- Cornea
- Differential diagnosis for tearing in this age group consists of foreign body, compromised corneal integrity (dystrophies, abrasions, ulcers, herpes simplex virus [HSV] keratitis, etc.), and glaucoma. These should be pertinent negatives.
- Conjunctiva
- True infectious conjunctivitis will present more acutely. Be sure to rule this out.
- Also, rule out allergic conjunctivitis, which can appear similarly, especially without significant discharge.
Testing for NLDO
When making the final assessment of NLDO, perform a tear drainage test. I utilize a combination of the Dye Disappearance Test (DDT) and a modified Jones I Test to confirm, as well as testing both eyes, to confirm it.
Both eyes are great to evaluate for differences and reference, especially if one eye is normal. A comparison of the tests is highlighted in Table 1.2
To check for pediatric NLDO:
- Instill 1 drop of fluorescein (Fl) dye in BOTH eyes and observe the tear lake with a cobalt blue light/filter.
- Wait 5 minutes and reassess the drainage in the tear lake AND the nasal cavity with a cobalt blue light/filter.
It can be helpful to take a photo of what the patient looks at the beginning and end of the test. Retention of dye in the tear lake that is the same AFTER the 5-minute mark is diagnostic of a complete NLDO. There will likely be no dye in the nasal cavity either.
Partial NLDOs will have some retention of dye in the tear lake and some dye in the nasal cavity. The diagnosis is then based on history combined with these results.2
Table 1: Comparison of the Dye Disappearance and Jones I Tests to diagnose an NLDO.
| Feature | Dye Disappearance Test (DDT) | Jones I Test |
|---|---|---|
| Purpose | Screens for nasolacrimal obstruction | Differentiates partial vs. complete obstruction |
| Procedure | Fluorescein dye placed in the eye, check after 5 minutes | Fluorescein dye placed in the eye. Check after 2 and 5 minutes with a cotton-tip applicator in the nasal cavity for dye |
| Positive Result | Fluorescein dye persists (abnormal drainage) | No dye recovered in nose (suggests complete obstruction) |
| Negative Result | Fluorescein dye disappears (normal drainage) | If dye reaches the nose, system is patent (partial vs. normal) |
| Invasiveness | Non-invasive | Minimally invasive |
Table 2: Courtesy of Patel et al.
Treatment options for nasolacrimal duct obstruction
Treatment for NLDO is typically observation under 12 months old because 90% of patients spontaneously resolve by 12 months.1
Other treatment considerations include:
- Lacrimal massage3
- Lacrimal massages create hydrostatic pressure in the lacrimal sac that can open the membranous blockage at the valve of Hasner.
- Some studies show that performing lacrimal massages can lead to a higher incidence of spontaneous resolution and earlier resolution, while others show that it is no better than observation.
- Antibiotics
- Since this is not an infectious condition, antibiotics are usually unnecessary and should be avoided.
- Surgical Intervention
- If symptoms have not resolved by 12 months, surgical intervention of nasolacrimal probing and irrigation, with or without stent, is recommended.
- Success rates are high, >80%, but can vary and are age dependent, with best outcomes prior to 2 to 3 years old.4
Another important consideration in cases of unilateral or asymmetric NLDO is its potential impact on refractive error. Several studies have suggested an association between unilateral NLDO and the development of refractive amblyopia.5 A comprehensive eye examination, including cycloplegic retinoscopy, is essential to assess for amblyopia at the time of diagnosis.
Even after successful surgical intervention, the risk may persist due to the timing of obstruction during the emmetropization process, warranting ongoing monitoring of visual development and refractive error.
For a refresher on performing comprehensive eye exams for children, check out Strategies for Early Pediatric Eye Consultations with Download!
Final thoughts
In closing, recognizing and confidently diagnosing NLDO is an important skill for every practicing optometrist, particularly when working with pediatric patients.
While often benign and self-resolving, NLDO requires a thoughtful clinical approach to differentiate it from more serious ocular conditions.
By combining a careful case history, thorough ocular examination, and strategic diagnostic testing, optometrists can ensure optimal outcomes for their young patients with NLDO.
