Canalicular Obstruction: A Leading Cause of Epiphora

Introduction:

The eyes incorporate punctum and canaliculus present with the eyelids. The punctum refers to the sharp tip of the parts of the human body. Here, the punctum highlights the small funnel-like draining holes seen in the corner of each of the upper and lower eyelids within the eye. The punctum is a valve that drains the utilized tears from the eye during every blinking action. Every punctum opens into a tube called the lacrimal canaliculus. The canaliculi in the upper and lower eyelids join the puncta and the lacrimal sac.

The lacrimal canaliculi or canaliculus are the tiny channels present in each eyelid. This helps drain the lacrimal fluid from the lacrimal punctum to the sac. The canaliculi are a significant part of the lacrimal apparatus, draining lacrimal fluid or tears from the ocular surface to the nasal cavity.

What Is Canalicular Obstruction?

Canalicular obstruction refers to the narrowing or occlusion of the tube draining lacrimal fluid within the punctum and lacrimal sac called the canaliculi. The incidence of canalicular obstruction has been known to occur in about 16 to 25 percent of individuals presented with epiphora (obstructive). The canalicular obstruction can occur in the common canaliculi, upper eyelid, or the lower one. Epiphora refers to excessive tearing, a common eye problem that nearly three percent of people come up with. The most common cause of epiphora is nasolacrimal duct obstruction and the canalicular obstruction.

What Are the Causes of Canalicular Obstruction?

There is no absolute cause for canalicular obstruction. Many conditions have been known to occur in association with canalicular obstruction. The etiologies can be acquired or congenital.

Acquired Canalicular Obstruction:

• Inflammatory and infectious conditions like viral infection, fungal disease, bacterial infections, Steven Johnson syndrome (rare and severe skin disorder), canaliculitis (inflammation of the lacrimal canaliculus), blepharitis (inflammation of the eyelids), and ectropion.

• Trauma or injuries, including chemical burns, thermal burns, and canalicular lacerations.

• Drug-induced canalicular obstruction can occur. The drugs involved include Pilocarpine, Timolol, Docetaxel, Idoxuridine, Fluorouracil, Paclitaxel, Dorzolamide, Dipiverfin, Betaxolol, Isotretinoin, Mitomycin, and Trifluridine.

• Iatrogenic problems from punctal cauterization (a kind of permanent punctal occlusion technique), post-surgical damages, radiotherapy, prior punctal plugs (tiny devices used to occlude the tear duct), and long-term usage of lacrimal intubation.

• Systemic diseases include lichen planus (an inflammatory skin condition), inflammatory bowel disease (diseases involving chronic inflammation of almost all digestive tract tissues), and malignancies.

Congenital Canalicular Obstruction:

Congenital canalicular obstruction can occur in which the lacrimal system is affected. The conditions include canalicular stenosis (narrowing or occlusion of the canalicular) or punctal stenosis (narrowing or occlusion of the punctum).

What Are the Signs and Symptoms of Canalicular Obstruction?

Canalicular obstruction is a blockage in the tear ducts or lacrimal ducts, resulting in several eye-related concerns. The signs and symptoms of Canalicular Obstruction include the following.

• Excessive tearing.

• Eye irritation.

• Eye redness.

• Discomfort in the affected eye.

• Mucous drainage (a sticky white or yellowish discharge from the eye).

• Swelling occurs proximal to the inner corner of the eye.

• Swollen tear sac, resulting in an obvious small lump.

• Recurrent eye infections.

• Excess moisture in the eyes.

• Overflow of tears.

• Mild degrees of blurred vision.

• Increased tear lake.

• Epiphora (increased production of tears).

• Stenosis (obstruction or narrowing) of the punctum.

• A challenge in passing prove or lacrimal dilator.

How Is Canalicular Obstruction Diagnosed?

The healthcare providers enquire about past and present medical history. So, the doctors check if there is any history of concurrent ocular and systemic diseases. Addedly, past surgeries, allergies, medications, trauma, and previous ocular treatments, particularly for dry eye infections, will be enquired and recorded. The doctors assess the eyelids and lacrimal system by Comprehensive and systematic eye examination. Other experimental examinations include the following:

• Slit Lamp Examination: This test helps evaluate the presence of fibrosis or membrane in the punctum. It also helps identify the pin Tim size, eyelid margin, eyelid malposition, height of tear meniscus, and any signs of past surgery.

• Schirmer Test: This test will aid in the identification of associated ocular surface abnormalities. This test also accompanies tear break-up time, tear meniscus height, and ocular surface staining.

• Dye Disappearance Test: It aids in the differentiation of hyper lacrimation and lacrimal drainage obstruction.

How Is Canalicular Obstruction Managed?

The management of canalicular obstruction relies on the etiology, position, and extent. The goals of management of canalicular obstruction in any individual include relieving the symptoms, maintaining the actual position of the canaliculi, and preventing its progression to total obstruction of the canaliculi. Maintaining the function of the other canaliculi is also considered during the treatment. The ophthalmologists might prescribe one or a combination of the following options tailored to each individual.

Medical Intervention:

Medical management is usually preferred for individuals at risk of developing canalicular obstruction. The clinical findings show that topical steroid eye drops and effective artificial tears might help prevent canalicular problems like fibrosis and scarring. Conservative treatment can be advised. In addition, treating underlying eye infections and inflammation like canaliculitis and conjunctivitis can help maintain the unobstructed quality.

Surgical Intervention:

The surgical treatment options are considered depending on the obstructions' location and extent. They include the following.

• Incomplete stenosis or obstruction of the canaliculi can be effectively treated with stents and intubations.

• Reconstruction is usually advised for the proximal to mid cases of canalicular obstruction. A focal part of the obstructed canaliculus near the punctum is excised here.

• The anastomoses of the cut follow this ends with a stent.

• Trephining of scarring is advised for distal canalicular obstruction. Stenting is given to prevent further contracture. This technique is then followed by balloon canaliculoplasty.

• In the case of total obstruction of canaliculi, the removal of the common canaliculi is advised.

• A significant surgery is usually recommended when the canaliculi are no longer treated or reconstructed.

What Are the Complications of Canalicular Obstruction?

There can be a recurrence of canalicular obstruction following the removal of the stent. Conjunctivitis is known to occur in most of the cases. Diplopia (double vision) and ectropion of the lower eyelid can result.

Conclusion:

Canalicular obstruction generally refers to any occlusion or blockage of the canaliculi. Obstruction in these draining ducts can result in significant problems such as discharge, excessive tearing, and discomfort. The management of canalicular obstruction involves certain procedures aiming to clear the blockage. It is essential to consult an ophthalmologist or other medical professional for an appropriate evaluation and guidance if one has any concerns regarding canaliculi and punctum.