Cm. Alper et al., ANTENATAL DIAGNOSIS OF A CONGENITAL NASOLACRIMAL DUCT CYST BY ULTRASONOGRAPHY - A CASE-REPORT, Prenatal diagnosis, 14(7), 1994, pp. 623-626
With proximal and distal obstruction to the lacrimal drainage system,
mucus accumulates forming a cyst. In order to diagnose a nasolacrimal
duct cyst antenatally, the sonographer must image the region adjacent
to the orbits.