Obstruction of Nasolacrimal Duct
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1- Introduction
2- Anatomical Overview
3- Causes
4- Treatment
Introduction
Obstruction of the nasolacrimal duct occurs when the tear duct that drains tears from the eye into the nose becomes blocked. This can lead to excessive tearing, recurrent eye infections, and inflammation. The condition is common in newborns, often resolving on its own, but it can also affect adults due to injury, infection, or age-related changes. Treatment ranges from simple massaging techniques and medications to surgical procedures to clear the blockage and restore normal tear drainage.
Anatomical Overview
Nasolacrimal duct obstruction, a condition in which tears are unable to drain properly from the eyes, can occur at various points along the nasolacrimal system. The tear drainage system begins with the puncta, small openings located on the inner corners of the upper and lower eyelids. From the puncta, tears flow through the canaliculi, which are small channels that lead to the lacrimal sac. The lacrimal sac is a small pouch located at the inner corner of the eye, where tears collect before entering the nasolacrimal duct. The nasolacrimal duct is a narrow tube that extends from the lacrimal sac into the nasal cavity. It passes through the nasolacrimal canal, a bony structure, before opening into the inferior nasal meatus.Obstruction of the nasolacrimal duct can occur due to various factors, such as inflammation, infection, or the presence of a foreign body. Symptoms of nasolacrimal duct obstruction include excessive tearing, mucoid discharge, and sometimes infection.
Causes
Congenital: In newborns, the duct may not be fully developed or may be blocked by a membrane at birth. This is one of the most common causes of tearing in infants and often resolves on its own within the first year of life.
Acquired:
- Age-related Changes: As people age, the nasolacrimal duct can narrow or become blocked due to changes in the surrounding tissues.
- Infections: Inflammation or infection of the duct or surrounding tissues can lead to swelling and obstruction.
- Trauma: Injury to the area around the eye or nose can cause scarring or damage to the nasolacrimal duct, leading to blockage.
- Tumors: Benign or malignant growths in the nasal cavity or lacrimal system can obstruct the flow of tears.
- Chronic Sinusitis: Inflammation of the sinuses can affect the drainage of the nasolacrimal duct.
- Medications: Some medications, such as certain eye drops, can cause irritation or inflammation of the duct, leading to blockage.
- Anatomical Abnormalities: Rarely, structural abnormalities of the nasolacrimal duct or surrounding structures can lead to obstruction.
Idiopathic: In some cases, the cause of nasolacrimal duct obstruction is unknown.
Treatment
Conservative Management: In cases where the obstruction is partial or not causing significant symptoms, a wait-and-watch approach may be recommended. This might involve warm compresses, massage over the lacrimal sac area, and antibiotic or anti-inflammatory eye drops to manage any associated infection or inflammation.
Probing and Irrigation: This procedure is often used for infants and involves inserting a thin probe into the nasolacrimal duct to clear the blockage. If successful, this can restore normal tear drainage.
Nasolacrimal Duct Intubation: In cases where probing is not successful, a thin tube (intubation) may be temporarily placed in the nasolacrimal duct to keep it open and allow tears to drain properly. This is often done under general anesthesia.
Dacryocystorhinostomy (DCR): In cases of persistent or severe obstruction, surgery may be required to create a new drainage pathway for tears. During a DCR procedure, a new connection is made between the lacrimal sac and the nasal cavity, bypassing the blocked duct.
Endoscopic DCR: This is a minimally invasive surgical procedure that uses an endoscope to create a new drainage pathway. It may result in less scarring and faster recovery compared to traditional DCR.
Balloon Dilation: In some cases, a balloon catheter can be used to dilate the nasolacrimal duct, helping to open up the blockage.