Dacryocystorhinostomy - Symptoms, Diagnosis, and Procedure

Who Needs a DCR?

Patients with nasolacrimal duct obstruction (NLDO) need DCR. The nasolacrimal duct carries tears from the lacrimal sac into the nasal cavity. This duct gets blocked due to various reasons; they are:

1. Congenital Nasolacrimal Duct Obstruction (CNLDO) - Seen in children and is a birth defect due to abnormal development of the nasolacrimal drainage system.

2. Primary Acquired Nasolacrimal Duct Obstruction (PANDO) - This is age-related fibrosis of the nasolacrimal duct.

3. Secondary Acquired Nasolacrimal Duct Obstruction (SANDO) - It can be further divided based on the etiology as follows:

a) Infection - It can be bacterial, fungal, viral, or parasitic.

b) Inflammation - Pain, swelling, and tenderness are classical signs of inflammation. It is a symptom rather than a cause; other than infection, different conditions that cause inflammation are mentioned below:

• Sarcoidosis - Autoimmune disorder manifesting as tiny granulomas in the lymph nodes and lungs.

• Wegener Granulomatosis (Granulomatosis with Polyangiitis - GPA) - Another autoimmune disease that causes inflammation of blood vessels in the nose, sinus, throat, lungs, and kidneys.

• Allergies - Also known as hypersensitivity, these are a series of reactions that occur when an individual's immune system gets exposed to certain substances like dust, bee pollen, etc.

• Ocular Drops - These are medications used as a treatment for conditions like glaucoma (eye condition) and viral infection, which can also cause inflammation.

• Irradiation - The use of I-131 (a radioisotope of iodine) for thyroid carcinoma can also cause inflammation.

• Burns - This includes chemical and thermal burns, which will cause inflammation, leading to nasolacrimal duct obstruction.

• Pemphigoid Disease - Affects skin and mucous membranes, causing blisters and rashes.

• Stevens-Johnson Disease - A condition mostly triggered by certain medication causing flu-like symptoms, followed by painful rash and blisters in the mucus membranes.

• Chemotherapeutic Drugs - These are medications used in cancer treatment; for example- docetaxel, a drug used to treat breast and lung cancer, can cause inflammation of the nasolacrimal duct.

c) Cancer- Different tumors cause lacrimal duct obstruction; they are-

• Lacrimal Gland Tumors - Lymphoma, papilloma, squamous cell carcinoma, and melanoma.

• Surrounding Soft Tissue Tumors - Basal cell carcinoma, adenoid cystic carcinoma, lymphoma, and leukemia.

• Metastatic Tumors - Breast carcinoma, metastatic melanoma, and prostate carcinoma.

d) Trauma - Seen in midfacial fractures, including naso-orbital-ethmoid fractures.

e) Mechanical - Mucoceles and dacryoliths also cause nasolacrimal duct obstruction.

Occasionally, women going through hormonal changes also develop nasolacrimal duct obstruction.

What Are the Symptoms of a Nasolacrimal Duct Obstruction?

Some of the causes mentioned above resolve without medical intervention, and others show serious symptoms that cause extreme patient discomfort. They are the following:

• Excessive tearing.

• Redness of the eye.

• Painful swelling.

• Crusting in the eye.

• Pus discharge from the lids.

• Blurred vision.

What Tests Are Done to Diagnose a Blocked Tear Duct?

Depending on the severity of the obstruction, the clinician can perform a few tests to diagnose; they are:

1. Tear Drainage Test - A drop of dye is placed in both eyes; if the dye does not drain, it indicates a tear duct block.

2. Eye Imaging - Same dye mechanism, but here an MRI or CT scan is used to locate the location of the blockage.

3. Irrigation and Probing - A lacrimal cannula or a slime-filled syringe is inserted into the punctum of the eye; if a soft stop is felt, it indicates a duct obstruction.

In a pediatric patient, the techniques mentioned above cannot be performed because of non-compliance.

How Is the DCR Procedure Done?

After patient evaluation, depending on the exact cause and location of the obstruction, the surgeon may choose different surgical approaches; they are:

1. External DCR - External DCR is done under anesthesia; the oculoplastic surgeon makes a small incision under the eye next to the nose, dissects the muscle and connective tissue, and carefully punches a hole (ostium) at the junction between the ethmoid and lacrimal bone. This is followed by creating a couple of flaps (lacrimal sac flap and nasal mucosal flap), which are then opposed (juxtaposed) and secured. The final step is wound closure; post-operative patients are prescribed antibiotics, decongestants, and steroids.

2. Endoscopic DCR - This is a minimally invasive procedure, and is often preferred by the surgeon. After the incision, an endoscope is used to locate the lacrimal sac (end of the nasolacrimal duct), and the rest of the procedure is similar to external DCR.

3. Punctoplasty - A few (two or three) incisions are made into the punctum to widen the opening. This allows the tears to drain easily and is commonly performed in elderly patients under local anesthesia. It is an outpatient procedure.

4. Canalicular Reconstruction - Done in patients after tumor removal or trauma. A stent (tube) is inserted into the punctum (opening at the eye's corner), allowing the tears to drain properly. The stent stays there for around three months till the underlying issue is resolved.

5. Canalicular Dacryocystorhinostomy - It involves dissecting the common canaliculus, removing the obstruction, and anastomosing it to the lateral wall of the sac.

6. Conjunctivodacryocystorhinostomy - Refers to creating a new passage to drain the tears from the conjunctival cul-de-sac directly into the nasal cavity with the help of tubes.

7. Dacryocystectomy - Complete removal of the lacrimal sac.

Are There Any Alternatives for DCR?

Additional treatments available for a blocked tear duct are the following:

1. Dilation, Probing, and Flushing - The clinician uses a probe to enlarge the duct opening at the corner of the eye and uses a lacrimal cannula (a thin tube) to flush out the blockage.

2. Balloon Catheter Dilation - Done under general anesthesia, the surgeon places a deflated balloon in the tear duct and then inflates it a few times to clear the blockage.

The clinician decides the type of procedure to be performed after careful evaluation.

What Are the Risks of DCR?

Both elective and emergency surgeries, in general, have associated risks, some of them in DCR are:

• Excess bleeding.

• Infection.

• Prominent facial scar.

• Abnormally fused tissue in the nose.

• Displacement of stent placed for drainage.

• Facial nerve injury.

• Sump syndrome (tears and mucus accumulate in the sac and discharge into the eye).

Conclusion -

DCR is performed by surgeons trained in the procedure with a thorough understanding of the patient’s anatomy. It is a safe and effective treatment for NLDO. DCR, along with maximal medical therapy (MMT) has been shown to have minimal side effects and reduced recurrence rate. Recent development includes the use of anti-fibrotic agents like mitomycin C (MMC); further studies are needed to test its efficiency in treating NLDO. With close post-operative follow-up care, most patients will be able to resume normal activities within two weeks. If a tube is placed, it would be removed after two to six months, which causes mild discomfort and pain, usually without more post-procedure issues.