Ophthalmology – Nasolacrimal Duct Obstruction

Basics

Description

Nasolacrimal duct obstruction (NLDO) is blockage of the lacrimal drainage pathway, preventing normal passage of tears from the lacrimal sac into the nasal cavity beneath the inferior turbinate.

It may cause:

• Epiphora
• Blurred vision from excessive tearing
• Mucous or purulent discharge
• Recurrent dacryocystitis

NLDO may be:

• Congenital
• Acquired

Acquired NLDO in adults can be divided into:

• Primary acquired nasolacrimal duct obstruction
• Secondary acquired nasolacrimal duct obstruction

Epidemiology

Acquired NLDO is more common in women.

A reported incidence is approximately:

20 per 100,000 persons

Female predominance is approximately:

3:1

One proposed explanation is that women may have a relatively narrower bony nasolacrimal canal.

Risk Factors

Important risk factors include:

• Chronic topical ophthalmic medications
• Long-term glaucoma drops
• Previous facial trauma
• Previous nasal or sinus surgery
• Recurrent dacryocystitis
• Recurrent conjunctivitis
• Systemic chemotherapy
• Previous radiation therapy

Chemotherapeutic agents associated with lacrimal drainage obstruction include:

• 5-fluorouracil
• Taxanes such as docetaxel

General Prevention

Many cases cannot be prevented.

Potential preventive measures include:

• Protective eyewear during high-risk activities to reduce facial trauma
• Appropriate management of chronic ocular surface inflammation
• Minimizing unnecessary long-term exposure to irritating topical medications
• Punctal occlusion techniques when appropriate to reduce systemic and nasolacrimal exposure to chronic eye drops

Pathophysiology

Primary Acquired NLDO

Primary acquired NLDO is thought to result from a chronic:

Fibro-inflammatory narrowing and scarring of the nasolacrimal duct

without a clearly identifiable initiating cause.

This progressive fibrosis eventually obstructs tear drainage.

Secondary Acquired NLDO

Secondary NLDO has an identifiable cause.

Major categories include:

• Infectious
• Inflammatory
• Neoplastic
• Traumatic
• Mechanical
• Iatrogenic

Infectious Causes

Reported infectious causes include:

• Bacterial infections
• Viral infections
• Fungal infections
• Parasitic infections

Chronic infection can promote:

• Mucosal inflammation
• Fibrosis
• Ductal obstruction

Inflammatory Causes

Associated inflammatory disorders include:

• Sarcoidosis
• Granulomatosis with polyangiitis
• Ocular cicatricial pemphigoid
• Scleroderma
• Chronic herpetic disease
• Radiation-related inflammation

Chronic topical medications may also induce cicatricial changes.

Neoplastic Causes

Tumors of the lacrimal sac or nasolacrimal drainage system are uncommon but important because they can masquerade as routine NLDO.

Reported tumors include:

• Squamous papilloma
• Squamous cell carcinoma
• Transitional-type carcinomas
• Adenocarcinoma
• Lymphoid tumors
• Melanoma
• Metastatic lesions

Trauma and Iatrogenic Causes

Obstruction may occur following:

• Facial fractures
• Canalicular laceration
• Previous probing
• Lacrimal surgery
• Nasal surgery
• Sinus surgery

Mechanical Causes

Mechanical obstruction may result from:

• Foreign body
• Dacryolith
• Canalicular concretions
• Mucous casts

Commonly Associated Conditions

Conditions associated with acquired NLDO include:

• Sarcoidosis
• Granulomatosis with polyangiitis
• Ocular cicatricial pemphigoid
• Scleroderma
• Herpetic conjunctivitis or keratitis
• Previous chemotherapy
• Previous radiation
• Chronic glaucoma therapy

Diagnosis

Diagnosis is based primarily on:

• History
• Eyelid and lacrimal examination
• Probing and irrigation
• Selected imaging when an atypical or secondary cause is suspected

History

The most common complaint is:

Persistent tearing

Usually the tearing is:

• Unilateral
• Constant or intermittent
• Worse outdoors or in cold/windy conditions

Patients may also complain of:

• Blurred vision
• Difficulty reading
• Difficulty driving
• Tears running down the cheek
• Mucous discharge
• Recurrent painful swelling near the medial canthus

Epiphora can have a substantial effect on daily activities and quality of life.

Physical Examination

A complete examination should first exclude other causes of tearing.

Assess:

• Eyelid position
• Punctal position
• Punctal stenosis
• Lash position
• Blink function
• Lacrimal pump function
• Conjunctiva
• Cornea
• Tear film
• Anterior chamber

Tear Meniscus

An elevated tear meniscus or increased tear lake supports impaired drainage.

A tear lake greater than approximately:

2 mm

may suggest significant outflow obstruction.

Lacrimal Sac Examination

Palpate the lacrimal sac region.

Pressure over the lacrimal sac may produce:

• Clear reflux
• Mucous reflux
• Mucopurulent material
• Purulent discharge

Reflux through the puncta supports obstruction distal to the canalicular system.

Important Tumor Warning Sign

A firm mass above the medial canthal tendon is particularly concerning for a lacrimal sac neoplasm.

Other warning features include:

• Bloody tears
• Bloody reflux
• Persistent unilateral symptoms
• Palpable firm mass
• Failure of standard treatment

These findings warrant imaging and specialist evaluation.

Nasal Examination

The nasal cavity should be assessed for:

• Septal deviation
• Inferior turbinate abnormalities
• Nasal masses
• Chronic inflammation
• Postsurgical changes
• Structural narrowing

ENT evaluation may be helpful in selected patients.

Diagnostic Testing

Laboratory Tests

Routine laboratory testing does not diagnose NLDO.

If purulent discharge is present, consider:

• Gram stain
• Bacterial culture
• Sensitivity testing

This is especially useful in:

• Recurrent infection
• Severe dacryocystitis
• Unusual organisms
• Treatment failure

Probing and Irrigation

Lacrimal probing and irrigation are among the most useful office tests.

They help determine:

• Whether the canaliculi are patent
• Whether obstruction is partial or complete
• Approximate level of obstruction

Interpretation of Irrigation

Fluid reaches the nose or throat

Suggests:

• Patent drainage system
• Possibly partial obstruction if flow is delayed or requires pressure

Reflux through the opposite punctum

Suggests obstruction distal to the common canaliculus or nasolacrimal duct.

Reflux through the same punctum

May suggest canalicular obstruction.

Jones Dye Tests

Jones I Test

A functional drainage test.

Fluorescein is placed in the conjunctival sac and recovery in the nose suggests functional drainage.

Jones II Test

Used when Jones I is negative.

It helps distinguish:

• Functional delay
• Partial anatomic obstruction

These tests are now used less commonly than direct irrigation and modern imaging.

Schirmer Testing

Schirmer testing measures tear production.

It may help determine whether tearing results from:

• Excessive tear production
• Reflex tearing
• Drainage failure

It does not directly diagnose NLDO.

Imaging

Routine imaging is not necessary in straightforward primary acquired NLDO.

CT or MRI

Imaging is indicated when there is concern for:

• Lacrimal sac tumor
• Nasal or sinus mass
• Orbital involvement
• Trauma
• Atypical obstruction
• Bloody tears
• Palpable mass
• Recurrent disease after surgery

CT is particularly useful for:

• Bone
• Sinuses
• Trauma

MRI is useful for:

• Soft tissue
• Suspected neoplasm
• Infiltrative disease

Dacryocystography

Dacryocystography can outline the anatomy of the lacrimal drainage system and localize obstruction.

It is now usually reserved for:

• Complex cases
• Recurrent obstruction
• Surgical planning

Dacryoscintigraphy

Dacryoscintigraphy using technetium can assess the functional transit of tears through the lacrimal system.

It is rarely required.

Pathology

Histopathology in primary acquired NLDO typically shows:

• Chronic inflammation
• Fibrosis
• Mucosal thickening

When obstruction is secondary to systemic disease, pathology may reveal the cause.

Examples include:

• Granulomatous inflammation in sarcoidosis
• Vasculitic inflammation
• Neoplastic cells

Differential Diagnosis

Not all tearing is caused by NLDO.

Important differential diagnoses include:

• Dry eye disease with reflex tearing
• Blepharitis
• Conjunctivitis
• Trichiasis
• Corneal foreign body
• Corneal abrasion
• Entropion
• Ectropion
• Punctal stenosis
• Canalicular obstruction
• Lacrimal pump dysfunction
• Acute angle-closure glaucoma
• Lacrimal sac tumor

Dry Eye and Reflex Tearing

Dry eye may paradoxically produce excessive tearing because ocular surface irritation stimulates reflex lacrimation.

Signs of ocular surface disease should therefore be sought before diagnosing NLDO.

Treatment

Definitive treatment of symptomatic complete acquired NLDO is usually surgical.

Medical therapy is mainly used to treat:

• Infection
• Inflammation
• Associated ocular surface disease

Dacryocystitis

Stagnant tears within an obstructed system can become infected, producing:

Acute dacryocystitis

Clinical features include:

• Pain
• Erythema
• Tender swelling below the medial canthus
• Purulent discharge
• Fever in more severe cases

Antibiotic Therapy

Acute dacryocystitis usually requires:

• Systemic antibiotics

Antibiotic selection should reflect:

• Severity
• Local microbial patterns
• Culture results when available
• Patient comorbidities

Severe infection may require intravenous antibiotics.

Actinomyces

Chronic canalicular infection caused by Actinomyces should be considered when there are:

• Recurrent unilateral discharge
• Canalicular swelling
• Concretions or dacryoliths

Definitive treatment usually requires removal of the concretions rather than antibiotics alone.

Dacryocystorhinostomy

DCR

Dacryocystorhinostomy (DCR) is the standard definitive treatment for symptomatic acquired distal NLDO.

The procedure creates a new drainage pathway between:

• Lacrimal sac
• Nasal cavity

bypassing the obstructed nasolacrimal duct.

External DCR

An external skin incision is used to access the lacrimal sac.

Advantages include:

• Excellent visualization
• High success rate
• Ability to obtain lacrimal sac tissue for pathology

Disadvantages include:

• Small external scar
• More disruption of medial canthal tissues

Endoscopic DCR

Performed through the nasal cavity.

Advantages include:

• No external scar
• Direct visualization of intranasal pathology
• Preservation of medial canthal structures

Success rates are generally comparable to external DCR when performed by experienced surgeons.

Silicone Intubation

A silicone stent may be used in selected DCR procedures to help maintain ostium patency.

It is not mandatory in every uncomplicated DCR.

It may be particularly useful in:

• Canalicular disease
• Revision surgery
• Complex anatomy
• Significant scarring

The duration of stenting varies according to the clinical situation.

Balloon Dacryoplasty

Balloon dilation may be considered for:

• Partial obstruction
• Selected stenotic lesions

Its success in acquired adult complete NLDO is generally lower than DCR.

Probing

Simple probing is:

• Often effective in congenital NLDO
• Generally much less effective as definitive treatment for established acquired adult NLDO

Referral

Refer to ophthalmology or an oculoplastic/lacrimal specialist when:

• Epiphora is persistent and affects quality of life
• Dacryocystitis occurs
• Obstruction is suspected
• A mass is palpable
• Bloody tears are present
• Surgery is being considered

In-Patient Considerations

Most NLDO is managed as an outpatient.

Hospital admission may be required if infection progresses to:

• Severe preseptal cellulitis
• Orbital cellulitis
• Sepsis
• Significant systemic illness

Follow-Up After DCR

Postoperative follow-up typically assesses:

• Wound healing
• Ostium patency
• Silicone stent position if one is used
• Infection
• Granulation tissue
• Recurrence of epiphora

If a stent prolapses or extrudes, the patient should contact the treating surgeon rather than manipulating it extensively.

Patient Education

Patients should understand that NLDO causes tearing because tears cannot drain normally into the nose.

They should seek prompt care for:

• Painful medial canthal swelling
• Purulent discharge
• Fever
• Increasing eyelid redness
• Visual symptoms
• Bloody tears

Prognosis

The prognosis is generally excellent after appropriate treatment.

DCR has a high success rate, commonly in the range of approximately:

80–95%

depending on:

• Surgical technique
• Cause of obstruction
• Canalicular involvement
• Prior surgery
• Surgeon experience

Complications of NLDO

Potential complications include:

• Chronic epiphora
• Mucous discharge
• Purulent discharge
• Recurrent conjunctivitis
• Dacryocystitis
• Preseptal cellulitis
• Orbital cellulitis

Surgical Complications

Rare complications of lacrimal surgery include:

• Bleeding
• Infection
• Scar formation
• Restenosis
• Stent displacement
• Granulation tissue
• Injury to surrounding structures
• Rare CSF leak
• Very rare intracranial infection

Ophthalmology Pearls

• Adult acquired NLDO typically presents with chronic unilateral epiphora.
• Primary acquired NLDO is usually caused by chronic fibro-inflammatory stenosis of the nasolacrimal duct.
• Always examine the eyelids, puncta, ocular surface, and nasal anatomy before assuming the tearing is caused by NLDO.
• Reflux of mucopurulent material with lacrimal sac pressure strongly supports distal drainage obstruction.
• A firm mass above the medial canthal tendon or bloody tears should raise concern for lacrimal sac neoplasm.
• Probing and irrigation are among the most useful diagnostic procedures.
• DCR is the standard definitive treatment for symptomatic complete acquired NLDO.
• External and endoscopic DCR both have high success rates.
• Balloon dilation is more suitable for selected partial obstructions than for complete adult NLDO.
• Acute dacryocystitis requires prompt systemic antibiotics; definitive surgery is usually performed after the acute infection has settled.
• Orbital cellulitis secondary to NLDO is uncommon but requires urgent hospital-based treatment.