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Evaluation of nasolacrimal system

Balasubramanian Thiagarajan

Why should we bother?

Otolaryngologists perform endoscopic dacryocystorhinostomy more and more

Helps in deciding whether the patient will benefit from this procedure

Operating surgeon should clinically examine patients before surgery

History

Anatomy of nasolacrimal pathway Hamurabi 2200 BC

Endo-DCR first described by Caldwell 1893

External DCR Toti in 1904

Epiphora (Downpour)

Excessive lacrimation

Defective drainage

Lacrimal pump failure

Classification of Epiphora

Congenital causes

Acquired causes

Congenital

1% of infants

Self limiting disorder

Massaging of the sac helps

Probing beneficial

Acquired

Primary acquired nasolacrimal duct obstruction

Dacryocystolithiasis

Orbital / lacrimal trauma

Canalicular lacerations

Actinomyces within canaliculi

Canalicular lesions following herpes / antiviral therapy (+ h/o keratoconjunctivitis)

Anatomical obstruction

Pathologies involving sac

Canalicular stenosis / blockage

Obstruction to nasolacrimal duct

Formation of diverticula

Types of obstruction

Intrinsic caused by internal derangements of the mucosal lining of lacrimal apparatus

Extrinsic Caused by extraneous deforming lesions which can deform the drainage channel as is the case in tumors.

Epiphora (Physiologic)

No anatomical changes in the lacrimal pathway

Lacrimal pump mechanism is at fault

Eye lid malpositions, eversion of punctum, poor orbicularis oculi muscle tone

Bell's palsy

Epiphora Grading (Sahlin)

GradeDegree of epiphora

0No epiphora

1Epiphora only outdoors and during windy times

2Outdoor epiphora No indoor epiphora

3Outdoor and indoor epiphora

Anatomy of lacrimal system

Nasolacrimal duct is 18mm long

Junction between common canaliculus and sac is guarded by Rosenmuller valve

Sites of lacrimal system block

Suprasaccal

Saccal

Subsaccal

Suprasaccal obstruction

Obstruction is proximal to sac

Upper canaliculus

Lower canaliculus

Common canaliculus

Herpes infection, trauma, irradiation

Saccal obstruction

Obstruction at the level of sac

Tumor

Diverticula

Trauma

Subsaccal obstruction

Incomplete

Compete

Functional obstruction

Lacrimal system is patent to syringing still there is epiphora

Obstruction is to be used only for anatomical obstruction

Causes of excessive tearing

Hypersecretion

Epiphora

Combination of both

Diagnostic evaluation

Quantification of tear production

Assessment of nasolacrimal system patency

Differentiating epiphora from lacrimation

Defining the pathological process

Differentiating anatomical from functional obstruction

Attempting to locate the site of obstruction

Classification of tests to evaluate lacrimal system pathway

Anatomical tests

Functional tests

Secretory tests

Anatomical tests

These tests helps in localization of obstruction

Palpation of sac

Syringing / irrigation

Diagnostic probing

Dacryocystography

Nasal exam

CT/MRI

Functional tests

To access functioning of lacrimal apparatus under physiologic conditions

Performed only when there is no evidence of obstruction in anatomical tests

Functional tests (contd)

Flourescein dye disappearance test

Scintigraphy

Jones dye test I

Sacharin test

Tests for lacrimal secretions

These tests are performed to access secretory functions of lacrimal apparatus

Schrimers test

Bengal Rose test

Tear-film break up

Tear lysozyme

Causes of excess lacrimation

Supranuclear causes Psychogenic / emotions

Stimulation of V nerve

Infranuclear causes

Lacrimal gland stimulation

Other causes Bright lights / sneezing

Stimulation of V nerve

Reflex tearing

Lid causes Blepharitis / trichiasis

Conjunctival diseases

Corneal diseases

Neuralgia

Ocular inflammation

Infranuclear causes

Facial palsy

Aberrant innervation

Crocodile tears

Epiphora causes

Functional insufficiency incorrect lid closure, lid malposition, punctal eversion, punctal medialization

Anatomical obstruction

Combination of functional insufficiency and anatomical obstruction

Combined epiphora

Facial nerve palsy corneal irritation and pump defects

Lower lid ectropion conjunctival irritation and pump defects

Thyroid diseases corneal irritation and defective canalicular function

History taking

Provides vital clues to the presence of canalicular disorders

H/o present /past opthalmological problems

Nasal symptoms

Previous surgeries

Unilateral tearing obstruction

Bilateral tearing - Physiological`

Inspection & palpation

Eye lids

Medial canthus

Palpation of sac

Eye lid examination

Lower lid laxity

Ectropion

Punctal eversion

Trichiasis

Blepharitis

Snap back test

Test for lower lid laxity

Lower lid is pulled down and away from the orbit

On release the lid resumes normal position

Time taken for the lid to get back to normal postion is noted

Longer the duration more lax is the lower lid

Graded over a scale of 0-4

Lid examination (contd)

Medial canthal laxity

Lateral canthal laxity

Orbicularis oculi muscle tone check

Examination of medial canthus

Neoplasm

Sac enlargement

Sac palpation

Normal sac not palpable

Sac is palpable below the medial canthus

Reflux of tears / pent up secretions

Pain / tenderness acute dacryocystitis

Dye excretion test

Drainage function of entire lacrimal apparatus can be tested

Fluorescein dye is used for this purpose

This test is more physiological

This test does not differentiate anatomical from physiological causes of nasolacrimal obstruction

Fluorescein dye test

1% fluorescein is instilled into the conjunctiva

Conjunctiva is not anaesthetized

After 5 mins thickness of fluorescein of the tear meniscus is measured using cobalt blue filter

This test can be safely performed in infants & children

Fluorescein dye test (contd)

Presence of residual fluorescein gives no information regarding localisation of block

Presence of residual fluorescein is an indication for probing and syringing

When performing this test in children they should be held in vertical postion

Dye test grading

0=No fluorescein in the conjunctival sac

1=Thin flurescing marginal tear drop persists

2=More fluorescein persists somewhere between 1 and 3 grades

3=Wide brightly fluorescein tear strip

Grades 0 and 1 are considered normal

False negative dye test

1. Large lacrimal sac2. Mucocele3. Distal nasolacrimal duct block

Break up time test

Performed by placing a drop of fluorescein in the outer canthus of the eye

Its transport can be observed from lateral to medial

Holes in the tear film can also be observed

Normal breakup time is 15-30 secs

Breakup time of less than 10 secs indicate epiphora

Jones dye test

Distinguishes between functional and anatomical obstruction

Topical xylocaine application

Flurescein dye instilled

Negative result indicates functional / anatomical block

Useless in total obstruction

Saccharin test

Similar to fluorescein dye test

Physiological

Saccharin is placed in conjunctiva

Saccharine taste appears within 3.5 mins

Pt should have normal taste sensation

Probing & syringing

Invasive test

Provides information regarding site of obstruction

Useless in functional obstruction

This is not a physiological test

This test should be interpreted with fluorescein dye test and clinical examination

Syringing (contd)

Topical xylocaine applied

Punctum dilator applied to dilate punctum

Tip of irrigator placed in the inferior canaliculus. It is directed first vertically and then horizontally. Eyelid is stretched

Tip is advanced 3-7 mm into canaliculus and saline is injected

Irrigation should not be forced

Syringing (Interpretation)

Regurgitation through opposite punctum obstruction in the common canaliculus or more distal structures

Regurgitation via the same punctum indicates punctal obstruction

Drainage via nose does not rule out physiological obstruction

Diagnostic probing

Hard stop

Soft stop

Irrigation / probing interpretation

Radiological evaluation

Dacryocystography

Nuclear lacrimal scintigraphy

CT

MRI

Dacryocystography

Anatomical investigation

Creates interior image of the entire lacrimal system

Radio opaque water soluble dye is injected into the canaliculus

Magnified images are created

Digital subtraction is used

Radiologic criteria of lacrimal pathology

Regurgitation of radio-opaque fluid into the conjunctival sac

Absence of fluid in the nose

Fluctuation of lumen of lacrimal system

Irregularity in contrast

Deformation involving lacrimal sac

Nuclear lacrimal scintigraphy

Non invasive physiological test

Utilizes radiotracer technitium-99M pertechnitate.

Images can be captured using epiphora

Drop of technetium-99m instilled into conjunctiva

Recording is made using gamma camera

20 mins is the recording time

CT/MRI

Helpful in identifying adjacent areas and other mass lesions

Secretory tests

Schimer's test

Rose bengal test

schirmer's test

35x5 mm paper

5 mins duration

10-30 mm wetness normal

Above 30mm epiphora

10mm dryness

Thankyou

Autor: drtbalugeetha 16.09.12