Children with blocked tear ducts have increased risk for ‘lazy eye’
MedWire News: The prevalence of "lazy eye'" risk factors in children with blocked tear ducts supports calls for early comprehensive eye examination.
Nasolacrimal duct obstruction (NLDO), or blocked tear duct, which affects around 6% of children, has been linked to an increased risk for "lazy eye" by US researchers. Amblyopia occurs in 1.6% to 3.6% of the US population and requires early treatment in order to prevent permanent sight damage.
Noelle Matta and David Silbert, of the Family Eye Group in Lancaster, Pennsylvania, USA, reviewed the records of 375 children under 3 years of age with NLDO for amblyopia risk factors. Amblyopia was defined as best-corrected visual acuity of 20/40 or worse in either eye, which was used alongside treatment history for the diagnosis.
They found that 82 (22%) of the children had amblyopia risk factors, which is eight times greater than the rate in the general population. Of the 70 children who were followed-up, 44 were treated for amblyopia, with 42 given glasses, 13 glasses and occlusion therapy, and two occlusion therapy alone. Six patients required surgery.
Of note, all children with anisometropia and unilateral NLDO, had higher hyperopia on the side with NLDO.
"What is especially interesting about this study is that all of the patients who required patching had amblyopia in the eye that had the blocked tear duct. This is strong evidence that the association of amblyopia and tear duct obstruction is more than coincidental," commented David Hunter, editor-in-chief of the Journal of the American Association for Pediatric Ophthalmology and Strabismus, in a press release.
The researchers explain that they do not yet know whether the correlation is due to early defocus caused by the presence of mucous in the eye, or to other mechanical or orbital factors that cause both NLDO and anisometropia simultaneously.
"We recommend that all children with congenital NLDO undergo comprehensive examination, including cycloplegic refraction, and be followed carefully if risk factors are present," conclude Matta and Silbert.
By Chloe McIvor