Symptoms and causes of blocked tear ducts

Tear duct obstruction is relatively common in clinical practice, and this symptom is also more obvious in infants. For symptoms of blocked tear ducts, babies may generally have symptoms of excessive tearing. The cause of tear duct obstruction cannot be ruled out as congenital developmental abnormalities.

1. Tears

Epiphora can be seen in infants. The tear drainage system is gradually formed during embryonic growth, with the nasolacrimal duct forming the latest. Often at birth, there is still a mucosal fold (Hasner valve) at the lower end of the nasolacrimal duct that partially or completely covers the nasolacrimal duct opening, which usually opens on its own within a few months after birth. The main cause of epiphora in infants is incomplete development of the lower end of the nasolacrimal duct, failure to complete "canalization", or the presence of membrane obstruction. Epiphora in infants can occur in one or both eyes. If there is secondary infection in the lacrimal sac, mucopurulent secretions may appear, forming neonatal dacryocystitis.

2. The tear duct is blocked and the liquid flows back from the tear puncta:

(1) Punctal occlusion: The puncta are membranous and occluded;

(2) Occlusion of lacrimal duct: The needle is inserted from the lacrimal punctum, and the liquid immediately flows back from the lacrimal punctum;

(3) Nasolacrimal duct obstruction: The needle is inserted from the lower lacrimal punctum, which is slightly smooth at first, and then flows out from the upper lacrimal punctum, without reflux of mucous or purulent secretions;

(4) Nasolacrimal duct stenosis: The needle is inserted from the lacrimal punctum, and some of the fluid flows back, while a small amount of fluid flows into the nasopharynx.

3. Congenital and developmental factors

Tear duct blockage may be caused by congenital factors or triggered by acquired factors, so we should not only protect ourselves but also the next generation. Congenital Hasner valve obstruction is the most common, and there are also congenital lacrimal duct atresia (including bony nasolacrimal duct atresia caused by bone deformity), congenital absence of lacrimal puncta, and nasal septum deviation.