22 May 2020 Author : Guilherme Castela Tears are produced by the tear glands. From this gland, they flow to the surface of the eyes. Then they are drained through the nasolacrimal duct to the nose and throat. When this duct is blocked, tears accumulate in the eyes . Obstruction of the nasolacrimal duct occurs in newborns, older children and even adults, although less frequently. It may be congenital (present at birth) or acquired . Congenital nasolacrimal duct obstruction Congenital obstruction of the nasolacrimal duct is a common disease in the first months of life and is the most common cause of epiphora in children. It can affect about 6%-20% of all newborns. At birth, 50% of children have a non-permeable nasolacrimal duct. Spontaneous perforation occurs during the first 3-4 weeks of life associated with sucking. Only a small percentage of children have a persistent epiphora after that, with more than 90% of cases resolving during the first year of life. What are the causes? The main cause of congenital obstruction of the nasolacrimal duct is the lack of permeability of a membrane - Hasner valve - located at the connection of the nasolacrimal duct with the nose. Less frequently, it can also be caused by distal bone narrowing in the nasolacrimal duct or hypertrophy of the inferior nasal turbinate. The main risk factor s identified for congenital nasolacrimal duct obstruction are: Maternal infection during pregnancy; Radiation; Craniofacial malformations; Down syndrome. Signs and symptoms of congenital nasolacrimal canal obstruction Symptoms begin during the first weeks of life. Constant and recurrent mucous secretions are the first sign identified by parents. The enlargement of the lacrimal meniscus and the epiphora usually begin after the second month of life. Symptoms are more often bilateral than unilateral and aggravate with upper airway infections. Congenital obstruction of the nasolacrimal duct may be accompanied by inflammatory signs of the periocular skin, conjunctivitis and dacryocystitis . It rarely causes cellulite. The presence of purulent conjunctivitis is not common, so antibiotic treatment is usually not necessary. Treatment Since spontaneous resolution is common during the first year of life, a conservative approach is recommended during this period. Conservative treatment consists of massaging the tear bag and washing the nose with saline . The massage is done with the index finger below the inner corner of the eye, a process that should be explained to the parents. The purpose of the lacrimal sac massage is to increase hydrostatic pressure leading to a rupture of the membranous obstruction. After 12 months , the probability of spontaneous resolution decreases and most children are treated with a procedure performed under general anesthesia (laryngeal mask), using a metal stylus - Bowman probe - which is introduced by the tear points and will pierce the membrane (Hasner valve) at the connection of the nasolacrimal duct with the nose. If the probe does not work, there are other surgical options, such as intubation with silicone and balloon dacrioplasty. Finally, when none of these treatments works, a new drainage route will have to be performed by creating a permanent fistula between the tear sac and the nasal cavity (dacryocystorhinostomy). The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
