What is Congenital Lacrimal Fistula?
Congenital lacrimal fistula is a rare condition that occurs from birth, where an extra or undeveloped tear duct forms a connection between the tear system and the skin. In some cases, these abnormal ducts might be blocked and not connect with the skin, making the condition less noticeable. The category of congenital lacrimal fistula is determined by where the duct starts – it could be from the common tear duct, the tear sac, or the nasolacrimal duct, which is the duct that drains tears from the eyes.
What Causes Congenital Lacrimal Fistula?
In a normal adult, the tear system includes parts like tear ducts, nasal tear ducts, sacs, and glands. To understand how a birth defect called congenital lacrimal fistula forms, we need to look at how the tear system develops while a baby is still in the womb.
In the early stages of development (around 32 days after fertilization), the nasal tear ducts start to form from a thickening in the forming eye and nose area. This duct system continues developing downwards from about the 60th day after fertilization. Tear ducts are usually there by the seventh month of fetal growth. When a baby is born, however, less than 30% have a fully open or ‘patent’ lower nasal tear duct.
Various theories have been proposed to understand why congenital lacrimal fistulae (the technical term for this birth defect) develop. Some researchers think that the abnormal tear leakage might result from too much growth of the outer wall of the nasal tear duct, issues with the closure of the eye-nose area, or strands of the amniotic sac. In some situations, inflammation can also lead to formation of these abnormalities, particularly when it is associated with a pus-filled inflammation around the tear sac.
Other researchers suggested that the birth defect might happen because the primordial tear structure doesn’t develop correctly. This could be due to abnormal development along its length. Some research emphasized that problems with the merging of the surface layer of the embryo after the thickening bags in might be the cause. Most of these theories suggest that the birth defect happens when the initial structures meant to form the tear system do not fade away correctly and keep developing abnormally.
Risk Factors and Frequency for Congenital Lacrimal Fistula
Congenital lacrimal fistulae is a condition that occurs in about 1 in every 2000 births, and it affects both sexes equally. However, these figures might be slightly off due to biased referrals and probable underestimation. This condition can be passed down through families, either dominantly or recessively, and sometimes as part of multifactorial syndromes. People of all ethnic backgrounds can get congenital lacrimal fistulae. Notably, if the fistulae is associated with a syndrome, it’s more likely to affect both sides of the body.
- Congenital lacrimal fistulae occurs in about 1 in every 2000 births.
- It affects both sexes equally.
- The condition can be hereditary, either as an autosomal dominant or autosomal recessive trait, and sometimes as part of complex syndromes.
- It can affect people of all ethnic groups.
- If the condition is related to a syndrome, it’s more likely to appear on both sides of the body.
Signs and Symptoms of Congenital Lacrimal Fistula
Congenital lacrimal fistulas, or small abnormal channels in the eye, typically appear near the inner corner of the eye, often on one side only. The skin around the area might become red and sensitive, and there may be a watery or puss-like discharge. Many times, these fistulas do not cause any discomfort, and may go unnoticed due to the tiny opening. However, in some cases, there can be teariness or discharge from the eye or the fistula, especially if there’s also a blockage in the tear duct. This can increase the risk of an infection in the tear sac, known as dacryocystitis.
Long term inflammation can result in blepharitis, a condition that results in reddening and swelling of the eyelids. People with excessive tearfulness (epiphora) usually have symptoms from birth, though some people may report experiencing symptoms later on due to occasional blockage of the tear duct. If the tear sac starts filling with mucous, it can create a feeling of fullness under the skin.
Though a physical exam can usually diagnose these fistulas, some may be missed, especially if they don’t connect with the skin surface. In children, a clear sign is if tears constantly flow from the unusual spot when they cry. A special test involving flushing the tear system with a salt solution mixed with a fluorescent dye can be used to see any opening in the skin or to check the flow in the tear duct.
Another technique, called the Valsalva maneuver, can cause discharge from the fistula to be more noticeable. Doctors also need to look out for other abnormalities, like a missing or partially formed tear duct, a blocked drainage system, a double tear-duct, blockages in the tear ducts, or extra tear ducts. Research suggests that patients with these issues have a higher likelihood of displaying widened space between the eyes (hypertelorism) or misalignment of the eyes (strabismus), especially in cases associated with syndromes.
Sometimes, a unique find during the clinical examination can help diagnose a congenital lacrimal fistula when it’s associated with certain facial disorders. Some examples include Goldenhar syndrome or CHARGE syndrome, characterized by multiple symptoms including those affecting the eyes, heart, choanae (back of nasal airway), growth, genitals, ears, and mental development.
Testing for Congenital Lacrimal Fistula
The most commonly used methods for diagnosing problems with the tear system involve probing, rinsing, and cleaning the tear ducts, and using radiology tests like dacryocystography or nuclear scintigraphy. During an initial doctor visit, a gentle probe of the fistula (an abnormal connection between two parts of the body) opening may be done, followed by an irrigation or washing out of the area.
A special test using fluorescein dye may be used for children who might not cooperate with the probing and washing process. In more complicated cases, advanced techniques have been used, such as dacryocystoendoscopy (a procedure that involves inserting a small tube into the tear duct to examine it), CT scans with contrast dye injected within the tear system, and making a model of the tear system using polyvinyl siloxane (a type of silicone).
Even though this casting method is not commonly used, some studies suggest it could help make 3-dimensional models of the tear system. In some cases, the dacryocystoendoscope (a small tube with a camera) helps the doctor to see the normal tear system and helps in placing a silicone drainage tube, which makes removing the fistula easier. In some instances, a blue dye called methylene blue has been used to trace the path of the fistula, especially during surgery.
Treatment Options for Congenital Lacrimal Fistula
If you have a fistula, a type of abnormal connection in your body, that isn’t causing symptoms and isn’t linked with a blockage in your tear duct, doctors usually recommend a wait-and-see approach. In certain cases, more active treatments are needed. These could include probing the tear duct, burning away the external opening of the fistula, or surgical removal of the fistula. Sometimes, doctors also perform a procedure to create a new tear duct. However, there is some disagreement about how effective this last option is.
Nowadays, doctors are less likely to burn away the fistula because it doesn’t always work and the fistula often comes back. Before removing the fistula, doctors need to check that the normal tear system is working properly. If not, there could be a risk of watery eyes or inflammation after the procedure.
For a case where the tear duct is also blocked, doctors might need to explore it. Simple probing and burning away the fistula might be risky especially if the fistula starts from the common tear passage. This approach could result in persistent teary eyes due to damage to the tear ducts.
The surgical removal of the fistula might be performed along with or without the procedure to create a new tear duct. If the fistula is removed from the outside, it is called a closed fistula removal. When combined with the procedure to create a new tear duct, it is called an open removal.
Originally, the procedure to create a new tear duct was performed from the outside. The benefit of this approach is that it can completely remove the fistula and provide a clear view of the internal opening. It can also address any blockages in the tear duct by creating a passageway around them. Several studies endorse this combined procedure, along with tubing in the tear passage, to deal with symptomatic fistulas.
A less invasive update to the external approach is an endoscopic technique. In this approach, doctors make a small hole in the bone of the wall adjacent to the tear duct socket and enlarge the tear sac into the middle passage. This method provides a better view of the internal opening, allows for a more thorough removal of the fistula, and sidesteps a potentially unattractive scar near the inner corner of the eye.
What else can Congenital Lacrimal Fistula be?
When trying to determine the cause of a condition related to the tear ducts, doctors should take into account other possible causes. These can include a fistula, which is an abnormal connection between two parts of the body. Fistulas in the lacrimal sac, which produces tears, can develop after infections that drain spontaneously or after injuries that can lead to facial fractures.
Other possible reasons can be to do with the structure of the tear ducts from birth. For example, the blockage of the tear duct might be present from birth, or there might be small, swollen sacs filled with mucus (mucoceles) that cause a constant overflow of tears that can make it seem like a congenital lacrimal fistula.
Doctors should also ensure they consider whether the patient might have certain syndromes that could be associated with tear duct issues, such as Down syndrome, VACTERL syndrome (a syndrome with a constellation of defects affecting different parts of the body), clefting syndromes like ectrodactyly-ectodermal dysplasia-cleft syndrome, or CHARGE syndrome.
What to expect with Congenital Lacrimal Fistula
Based on the largest collection of cases, there’s an 11% chance of the fistula, a type of abnormal connection in the body, returning after treatment. However, it’s challenging to provide a precise percentage due to the variety of causes. Additionally, how a person with a congenital lacrimal fistula – a birth defect involving a tear duct – will fare generally depends on how serious the fistula is and where it’s located.
In most instances, the fistula is found near the punctum, which is an opening near the corner of the eye. If the condition isn’t treated, patients may face repeated infections, constant tearing from the eye, and even loss of sight.
Possible Complications When Diagnosed with Congenital Lacrimal Fistula
The most difficult problem to manage after a congenital lacrimal fistula is typically its recurrence. Other common issues include infection leading to dacryocystitis, cosmetic issues, bleeding, and injury to the eyelid structures. Examining potential complications related to the presence of a congenital lacrimal fistula, we can note:
- Recurrent infections: The unusual passage between the tear sac and the skin lets germs into the tear sac, often causing repeated infections. Symptoms might include redness, swelling, discharge, and pain.
- Chronic inflammation: This abnormal passageway can keep the area around the eye inflamed, resulting in discomfort, pain, and swelling.
- Tear duct obstruction: The fistula can block the standard tear flow from the eye, causing watery eyes, blurry vision, and a higher chance of eye infections.
- Cosmetic concerns: Having a visible fistula near the eye can create self-image problems, particularly for children. This can lead to social anxiety, low self-esteem, and emotional problems.
- Speech delay: Very rarely, the presence of a congenital lacrimal fistula can be associated with delayed speech development in infants. It’s believed to be due to the unusual connection influencing the muscles and nerves surrounding the mouth.
Identifying and treating a congenital lacrimal fistula early is crucial to avoid these complications. The standard treatment typically involves surgery to close the fistula and return the eye’s normal tear flow. With quick and suitable treatment, most children with this condition can have a favorable outcome and evade long-term complications.
Preventing Congenital Lacrimal Fistula
It’s crucial for patients to quickly get medical advice if they persistently have a watery eye, suddenly develop an infection near the inner corner of the eye, or show symptoms typically associated with dacryocystitis, an inflammation of the tear sac. This is especially important in children. Existing medical literature may not fully represent the number of undiagnosed cases due to reporting bias, emphasizing the importance of seeking medical attention early.
