What is Congenital Nasolacrimal Duct Obstruction?
It is the failure of the nasolacrimal duct (a drainage duct or pathway starting at the nasal corner of the eyelids and emptying into the nose) to develop fully and not complete its path into the nasal cavity. There is a blockage of the tear drainage system right before it is supposed to open into the nose. Obviously, if this diagnosed in a new born it is classified as congenital.
What Causes Congenital Nasolacrimal Duct Obstruction?
swollen lacrimal sac
During the development of the unborn child, the nasolacrimal duct begins to form as it starts from the medial portion of the eyelid. It then forms the lacrimal sac and then forms a duct into the nose. In about five percent of children, the duct fails to complete its journey into the nasal cavity. There is no difference between boys and girls. There is no none genetic predisposition.
There can be other congenital defects in the development of the nasolacrimal duct system but the distal obstruction is by far the most common.
The Signs and Symptoms of Congenital Nasolacrimal Duct Obstruction
There is usually tearing of the eye or epiphora, discharge, redness of the eyelid especially nasally, chapping of the skin in one or both eyes. There may be swelling of the area medial to the lower eyelid. The eye itself may show no signs of infection or can have some redness.
Diagnosing Congenital Nasolacrimal Duct Obstruction
The child presents with a tearing eye, tear film increased, discharge in the eye, possible mass or swollen area nasal to the lower lid, and the eye may be white or red. When pressure is applied to the nasal area medial to the lower eyelid, discharge is expressed from the drainage system through the puncta.
Fluorescein dye instilled into the eye should disappear or be reduced significantly five minutes after instillation. If not then an obstruction is present.
Management and Treatment of Congenital Nasolacrimal Duct Obstruction
Medical management consists of lacrimal massaging, treatment with topical antibiotics, and sometimes systemic antibiotics. Warm compresses may also be applied.
If medical treatment is not effective, then surgical intervention may be necessary.
Probing of the Nasolacrimal Duct Obstruction
Some eye doctors may chose to probe the infant around age six months in the office. Other eye doctors prefer to wait and see if the obstruction clears on its own. They tend not to probe until age one which at that time will be done in the hospital as an out-patient.
A small probe is inserted into the puncta (opening of the nasolacrimal duct system on the medial edge of the eyelids). The probe is passed into the lacrimal sac and then into the nose. This procedure is approximately ninety percent successful. Repeat probings are much less successful, generally fifty percent or less.
Insertion of a Stent into the Nasolacrimal Duct
This procedure is usually used after the probing of the nasolacrimal has failed. There are some eye doctors who may prefer to do this procedure right after failure of medical therapy. A silicone tube or stent is place through both upper and lower lid puncta or through just one puncta into the nose. This will be left in place from two months to six months in most cases. The success rate for this procedure is approximately ninety percent.
This procedure is done when all other treatments have failed. It can be done from inside the nose or an external approach through the skin. This makes a direct opening form the lacrimal sac into the nose.
The treatment initially consists of lacrimal message with the treatment of any infections with antibiotics. If the obstruction does not resolve then a simple probing is usually the next step. Nasolacrimal duct stents followed by DCR are used if the probing does not resolve the obstruction. The success rate for treating congenital nasolacrimal duct obstruction is better than ninety percent