Unilateral Congenital Nasolacrimal Duct Obstruction Linked With Anisometropia Prevalence

Infected tear duct.
Ophthalmology. Infected tear duct. Inflammation and swelling around the lacrimal punctum of a 3 year old girl with a blocked tear duct.
Clinicians are reconsidering the notion that congenital nasolacrimal duct obstruction has no impact on visual development in children.

Unilateral congenital nasolacrimal duct obstruction (CNLDO) is associated with a higher prevalence of anisometropia compared with bilateral CNLDO in children, according to a study published in the Journal of  the American Association for Pediatric Ophthalmology and Strabismus.

Researchers prospectively assessed refractive status and anisometropia prevalence in a cohort of pediatric patients with CNLDO to assess their risk of amblyopia. They evaluated children with unilateral (n=205, mean age 11.73±12.6 months, 50.2% boys) and bilateral (n=103, mean age 11.49±12.9 months, 50.5% girls) CNLDO from November 2017 through May 2019. The team managed the condition in children less than 1 year old with Crigler massage (52.9%) while using probing (5.8%) or both probing and irrigation (41.2%) on older children with persistent irrigation. They performed cycloplegic refraction at baseline, and at 3 and 6 month follow-up visits.

The investigators determined that patients with unilateral CNLDO had a higher rate of anisometropia compared with patients with bilateral CNLDO (11.2% vs 1.9%, P =.005), and that the affected eye was more ametropic compared with the unaffected eye.

They also noted that patients with unilateral CNLDO had greater differences in sphere (P <.001), cylinder (P =.019), and spherical equivalent (P <.001) between affected and  unaffected eyes, but observed no such differences between the eyes of patients with bilateral CNLDO.

Overall, hypermetropia (45.4%), astigmatism (25.8%), and emmetropia (24.9%) were the most common refractive errors in the affected eye for patients with unilateral CNLDO, while emmetropia (45.4%) and hyperopia (32.2%) were the most common refractive errors in the patients’ unaffected eyes. Patients with bilateral CNLDO were mostly hyperopic (39.5%) or emmetropic (34.9%), with some children presenting with astigmatism (14%) and myopia (11.6%).

“CNLDO affects 20% of children globally,” according to the researchers. Despite the previously held assumption that the condition bears no significance to visual development in children, “the association between CNLDO and visual maturation is currently under debate.”

Limitations of the study include the absence of age-matched controls, a limited follow-up period, and the exclusion of patients with strabismus.


Hareendran H, Allapitchai F, Ravindran M, Shukul K, Rengappa R. Anisometropia and refractive status in children with congenital nasolacrimal duct obstruction—a prospective observational study. J AAPOS. Published online March 18, 2022. doi:10.1016/j.jaapos.2021.11.015