In examining the prevalence and epidemiology of congenital nasolacrimal duct obstruction (CNLDO), a new study found the condition was diagnosed in one-in-nine children and had no gender preference; however, researchers found a higher rate of CNLDO in Caucasians.

Researchers from the Mayo Clinic in Rochester, Minn., reviewed the medical records of children ages five and under who had been diagnosed with CNLDO from 1995-2004. This large population-based cohort study was first reported in the British Journal of Ophthalmology.

Out of 17,713 newborns, 1,998 were diagnosed with CNLDO at a median age of five weeks. Compared with the reference population, CNLDO was associated with premature birth and was more prevalent among Caucasians. Two-thirds of patients initially presented with discharge alone, 18% with tearing alone and 15% with both discharge and tearing.

“Prematurity and Caucasian race were associated with the development of CNLDO,” researchers said. “Mucopurulent discharge was a much more common feature than tearing at initial presentation.”