Causes of a Causes of a watering eye  watering eye  and and    Evaluation  Evaluation 

Anatomy Anatomy The lacrimal drainage system consists of The lacrimal drainage system consists of

the following structures :the following structures : The punctaThe puncta The canaliculiThe canaliculi The lacrimal sacThe lacrimal sac The nasolacrimal ductThe nasolacrimal duct

The lacrimal apparatusThe lacrimal apparatus

Lacrimal sacLacrimalgland

Excretory ductsof lacrimal gland

Lacrimal punctum

Lacrimal canaliculus

Nasolacrimal duct

Inferior meatusof nasal cavity

Nostril

Tears:Convey social information, hydrate the eye, contain an antimicrobial agent, drain into mucous membrane of nose

Lacrimal ApparatusLacrimal Apparatus lacrimal glandslacrimal glands

produces and drains tearsproduces and drains tears lacrimal fluidlacrimal fluid

watery solution containing salts, watery solution containing salts, some mucus, and lysozymesome mucus, and lysozyme

protects, cleans, lubricates and protects, cleans, lubricates and moistens the eyeballmoistens the eyeball

spreads from lateral to medial by spreads from lateral to medial by blinkingblinking

about 1mL of lacrimal fluid per dayabout 1mL of lacrimal fluid per day

Figure 16.7bFigure 16.7b

Physiology Physiology

Tears secreted by the main and accessory lacrimal glands pass across the Tears secreted by the main and accessory lacrimal glands pass across the ocular surface. A variable amount of the aqueous component of the tear film is ocular surface. A variable amount of the aqueous component of the tear film is lost by evaporation. This is related to the size of the palpebral aperture, the lost by evaporation. This is related to the size of the palpebral aperture, the blink rate, ambient temperature and humidity. The remainder of the tears drain blink rate, ambient temperature and humidity. The remainder of the tears drain as follows  as follows  

aa    Tears flow along the upper and lower marginal strips and enter the upper     Tears flow along the upper and lower marginal strips and enter the upper and lower canaliculi by capillarity and also possibly by suction.and lower canaliculi by capillarity and also possibly by suction.

b b    With each blink, the pretarsal orbicularis oculi compresses the ampullae,    With each blink, the pretarsal orbicularis oculi compresses the ampullae, shortens and compresses the horizontal canaliculi and moves the puncta shortens and compresses the horizontal canaliculi and moves the puncta medially. Simultaneously, the lacrimal part of the orbicularis oculi, which is medially. Simultaneously, the lacrimal part of the orbicularis oculi, which is attached to the fascia of the lacrimal sac, contracts and compresses the sac, attached to the fascia of the lacrimal sac, contracts and compresses the sac, thereby creating a positive pressure which forces the tears down the thereby creating a positive pressure which forces the tears down the nasolacrimal duct and into the nose (Fig. 2.2B and C).nasolacrimal duct and into the nose (Fig. 2.2B and C).

    cc     When the eyes open the muscles relax, the canaliculi and sac expand    When the eyes open the muscles relax, the canaliculi and sac expand creating a negative pressure which, assisted by capillarity, draws the tears creating a negative pressure which, assisted by capillarity, draws the tears from the eye into the empty sac.from the eye into the empty sac.

Watering from eye

LACRIMATION : excessive secretion of tear,

due reflex stimulation of lacrimal gland

EPIPHORA : defective drainage of tear,

due to fault in the lacrimal passage

LacrimationLacrimation

Cause are :Cause are :1.1. Psychic stimulation as in weeping or laughingPsychic stimulation as in weeping or laughing2.2. Irritation of the cornea or conjunctiva, by Irritation of the cornea or conjunctiva, by

dust , fumes, chemicals. Foreign body, dust , fumes, chemicals. Foreign body, inflammation. Etcinflammation. Etc

3.3. In coughing, sneezing, vomitingIn coughing, sneezing, vomiting4.4. Exposure to bright light Exposure to bright light 5.5. Corneal ulcer, abrationCorneal ulcer, abration6.6. Different type of keratitisDifferent type of keratitis7.7. Trichiasis , ectropion Trichiasis , ectropion

Epiphora

Epiphora: Greek terminology meaning “Downpour”. This is defined as excessive watering of

eye. This is invariably caused by obstruction to tear drainage.

epiphoreepiphore

Cause :Cause :1.1. Mechanical obstruction in the drainage Mechanical obstruction in the drainage

system due to—system due to—- Congenital absence, or occlusion of the puncta- Congenital absence, or occlusion of the puncta- Canaliculitis, canalicular obstruction- Canaliculitis, canalicular obstruction- Congenital dacryocystitis- Congenital dacryocystitis- Chronic or acute dacryocystitis- Chronic or acute dacryocystitis- Neoplasms of the lacrimal sac- Neoplasms of the lacrimal sac- Nasal pathology, like polyps, tumours in the - Nasal pathology, like polyps, tumours in the

inferior meatus of the nose.inferior meatus of the nose.

epiphoreepiphore

Actinomyces within the canaliculi – Actinomyces are anaerobic gram positive bacilli resembling fungi. These organism are normal commensal of oropharynx. These organism are capable of causing cast – forming canaliculitis leading onto lacrimal tract obstruction.

Canalicular infections following herpes infections / ectropion – Viral infections constitute a well recognised common cause of acquired canalicular obstruction These patients give history of an episode of blepharokeratoconjunctivitis before epiphora. Antivirals (idoxuridine) which are prescribed for this condition too add to the woes by causing more lacrimal obstruction.

epiphoreepiphore

Lacrimal pump failure due toLacrimal pump failure due to

- Lower lid laxityLower lid laxity

- Weakness of the orbicularis occuli, as in Weakness of the orbicularis occuli, as in bell’s palsybell’s palsy

- Ectropion due to other causeEctropion due to other cause

Clinical examination goal in these patients is to distinguish between epiphora and lacrimation.

While epiphora needs to be surgically managed medically. The focus should be in differentiating

anatomical obstruction from functional disorders.

Anatomical obstruction: Obstruction to the lacrimal drainage system is

the feature to look for in this condition. Pathological changes could be seen involving the lacrimal sac, irregularities in lacrimal drainage system (canalicular stenosis, canalicular blockage, obstruction to nasolacrimal duct, diverticulous formation etc.) Lacrimal pathways can be obstructed due to internal derangements like inflammation of the epithelial linining. This is known as intrinsic obstruction. If lacrimal pathways are affected by deforming lesions from outside like tumors causing compression to it has been termed as extrinsic obstruction.

Physiologic dysfuntion causing epiphora:This is also known as functional epiphora. Here there are no anatomical changes to the lacrimal pathway. The functioning lacrimal pump mechanism is at fault. Pump mechanism can be affected in conditions like eyelid malpositions, eversion of lacrimal punctum, poor orbicularis oculi muscle tone as seen in patients with Bell's palsy.

Grading of epiphora

The commonly used grading system was devised by Sahlin

Grade Degree of Epiphora

00 No epiphora

11 Epiphora only outdoors and during windy times

22 Outdoor epiphora No indoor epiphora

33 Outdoor and indoor epiphora

Sites in the lacrimal system prone for obstruction:

Suprasaccal obstruction: In this type obstruction lies proximal to the

lacrimal sac. Obstruction can occur at the level of upper

canaliculus, lower canaliculus and common canaliculus. Obstruction in these areas can occur

following herpetic infections, taruma, irradiation.

Saccal obstruction: Here obstruction occurs at the level of lacrimal sac. This could be caused by tumors, diverticula,trauma etc

Subsaccal obstruction: In this category the obstruction lies below the

level of lacrimal sac. This condition commonly requires endoscopic dacryocystorhinostomy. This obstruction is more common than the rest.

Causes include: 1. Congenital nasolacrimal duct obstruction 2. Primary acquired nasolacrimal duct

obstruction 3. Nasolacrimal duct

obstruction following FESS

showing total subsaccular obstruction

Evaluation of watering Evaluation of watering from the eye from the eye

HistoryHistory

1.1. Watering due to epiphore is usually Watering due to epiphore is usually unilateral and is not associated with unilateral and is not associated with irritationirritation

On the other hand lacrimation is usually On the other hand lacrimation is usually bilateral and associated with bilateral and associated with irritation,itching or photophobia irritation,itching or photophobia

Clinical history

This is a very important aspect of lacrimal apparatus examination. This will provide vital clues to the presence of canalicular disorders.

History should include patient's present and past ophthalmological problems, nasal symptoms, medical and interventional relevant procedures also.

Unilateral tearing usually indicate obstructive pathology whereas bilateral tearing could be physiological. A child with a history of tearing since birth should arouse suspicion of membranous obstruction to nasolacrimal duct. Nasal disorders like nasal polyposis / sinusitis can also cause unilateral epiphora.

histroyhistroy

Past history of bell’s palsy is important, it Past history of bell’s palsy is important, it suggest lacrimal pump failure rather than suggest lacrimal pump failure rather than a mechanical obostruction.a mechanical obostruction.

h\o of medication like, topical idoxuridine h\o of medication like, topical idoxuridine (IDU), Phospholone iodine ans systemic (IDU), Phospholone iodine ans systemic 5-FU (fluoro-uracil) may be cause of 5-FU (fluoro-uracil) may be cause of punctal stenosispunctal stenosis

When to Contact DoctorWhen to Contact Doctor

You should consult your You should consult your doctor if you are if you are experiencing: experiencing:

Unexplained tearing over a long period Unexplained tearing over a long period Eyes that are red and producing Eyes that are red and producing

discharge discharge Watery eyes and eye pain Watery eyes and eye pain Watery eyes and sore sinuses Watery eyes and sore sinuses

examinationexamination

Inspection and

palpation

Inspection and palpation should involve the following areas:

1. Eyelids 2. Medial canthus 3. Palpation of lacrimal sac

Eye lid examination:

Look out for lower eyelid laxity Ectropion Punctal eversion Trichiasis Blepharitis

Eye lid examination: Snap-back test – This test is performed by pulling the

lower eye lid down and away from the globe and held for several seconds. On release the lower lid resumes its normal position. The time taken for resumption of normal position is noted. The patient should not blink during the test. This test provides an assessment of laxity of lower lid. The longer it takes for the lower lid to spring back to position the more lax it is. This test is graded on a scale of 4 starting from 0. 0= normal and 4= lax lower lid.

Medial canthal laxity Lateral canthal laxity Orbicularis oculi muscle tone check Pinch test – This test helps to assess orbicularis oculi

muscle tension.

Evaluation Evaluation External examination External examination     11        The puncta and eyelidsThe puncta and eyelids are best examined on the slit-lamp are best examined on the slit-lamp

for evidence of the following conditions:for evidence of the following conditions:         AA Punctal stenosis.Punctal stenosis.

    B B   ) ) Ectropion causing malposition of the punctum, often Ectropion causing malposition of the punctum, often associated with secondary stenosis (Fig. 2.3Aassociated with secondary stenosis (Fig. 2.3A

..    CC      Punctal obstruction by an eyelash (Fig. 2.3B) or a fold Punctal obstruction by an eyelash (Fig. 2.3B) or a fold of redundant conjunctiva (conjunctivochalasis – Fig. 2.3C).of redundant conjunctiva (conjunctivochalasis – Fig. 2.3C).

D D A large caruncle displacing the punctum away from A large caruncle displacing the punctum away from the globe (Fig. 2.3D).the globe (Fig. 2.3D).

    EE      A pouting punctum is typical of canaliculitis (Fig. A pouting punctum is typical of canaliculitis (Fig. 2.3E).2.3E).  

    F F  Centurion syndrome is characterized by anterior Centurion syndrome is characterized by anterior malposition of the medial part of the lid, with malposition of the medial part of the lid, with displacement of puncta out of the lacus lacrimalis displacement of puncta out of the lacus lacrimalis due to a prominent nasal bridge (Fig. 2.3F).due to a prominent nasal bridge (Fig. 2.3F).

Examination of medial canthus:

Lacrimal sac enlargement will be seen as mass below medial canthal tendon.

Enlargement above medial canthal tendon indicates neoplasm.

palpationpalpation

The lacrimal sacThe lacrimal sac should be palpated. Punctal should be palpated. Punctal reflux of mucopurulent material on lacrimal reflux of mucopurulent material on lacrimal compression is indicative of a mucocele with a compression is indicative of a mucocele with a patent canalicular system, but with an patent canalicular system, but with an obstruction either at or distal to the lower end obstruction either at or distal to the lower end of the lacrimal sac. In acute dacryocystitis of the lacrimal sac. In acute dacryocystitis palpation is severely painful and compression palpation is severely painful and compression should be avoided. Rarely, palpation of the sac should be avoided. Rarely, palpation of the sac will reveal a stone or a tumour.will reveal a stone or a tumour.

NASAL EXAMINATIONNASAL EXAMINATION

To detect DNS polyp or tumour.To detect DNS polyp or tumour. To detect hypertrophy of the inferior To detect hypertrophy of the inferior

turbinateturbinate To detect the position of anterion end of To detect the position of anterion end of

the middle turbinate when DCR is the middle turbinate when DCR is contemplatedcontemplated

To know the condition of the nasal To know the condition of the nasal mucosa.mucosa.

Diagnosis of epiphora the Phylosophy behind it: Theoretically speaking excessive tearing may be

caused by - Hypersecretion Epiphora Combination of both

Diagnostic evaluation should include: 1. Quantification of tear production 2. Assessment of nasolacrimal system patency 3. Differentiating epiphora from lacrimation 4. Defining the pathological process of epiphora 5. Differentiating anatomical from functional obstruction 6. Attempting to locate the obstruction in order to

define the optimal surgical approach

Classification of Tests for lacrimal drainage pathway:

Anatomical tests Functional tests Secretory tests

Anatomical tests:

These tests are performed to locate the probable area of lacrimal tract obstruction. These tests include:

Palpation of lacrimal sac Syringing / irrigation Diagnostic probing Dacryocystography Nasal examination CT / MRI

Functional tests: These are performed to access the function of

lacrimal apparatus under physiologic conditions.

This test is performed if there is no obstruction as evdenced by negative anatomical tests.

These tests include: Flourescein dye disappearance test Scintigraphy Jones dye test I Sacharin test

Knowledge of various causes of lacrimation and epiphora really helps in clinical examination ofthese patients

Excess lacrimation:Supranuclear causes – Psychogenic

/ emotionsStimulation of V cranial nerve –

(Reflex tearing)Lid causes (Blepharitis / Trichiaris)

Conjunctival diseasesCorneal diseases

NeuralgiaOcular inflammation

Infranuclear causes – facial palsy, abberant innervation,

crocodile tearsLacrimal gland stimulation

Others – Bright lights, sneezing

Epiphora:Functional insufficiency

Incorrect lid closureLid malposition

Punctal eversionPunctal medialization

Anatomical obstructionCombined lacrimation / epiphora – A

combination of the above two categoriesFacial nerve palsy –

Corneal irritation and pump defectsLower lid ectropion –

Conjunctival irritation , Ineffective pump mechanism

Thyroid diseases – Corneal irritation,

defective canalicular function

Fluorescein Fluorescein disappearance testdisappearance test

Fluorescein disappearance testFluorescein disappearance test The marginal tear strip of both eyes should The marginal tear strip of both eyes should

be examined on the slit-lamp prior to any be examined on the slit-lamp prior to any manipulation of the eyelids or instillation of manipulation of the eyelids or instillation of topical medication, as these may prejudice topical medication, as these may prejudice the clinical picture. Many patients with the clinical picture. Many patients with watering do not have obvious overflow of watering do not have obvious overflow of tears onto the face but merely show a high tears onto the face but merely show a high marginal tear strip on the affected side . The marginal tear strip on the affected side . The fluorescein disappearance test is performed fluorescein disappearance test is performed by instilling fluorescein 2% drops into both by instilling fluorescein 2% drops into both conjunctival fornices. Normally, little or no conjunctival fornices. Normally, little or no dye remains after 5 minutes. Prolonged dye remains after 5 minutes. Prolonged retention is indicative of inadequate lacrimal retention is indicative of inadequate lacrimal drainage and can be graded from 1–4.drainage and can be graded from 1–4.

Jones dye testing Jones dye testing

Dye testing is only indicated in patients Dye testing is only indicated in patients with suspected partial obstruction of the with suspected partial obstruction of the drainage system. These patients drainage system. These patients manifest epiphora, but the lacrimal manifest epiphora, but the lacrimal system can be successfully irrigated. Dye system can be successfully irrigated. Dye testing has high false positive and testing has high false positive and negative rates and is of no value in the negative rates and is of no value in the context of total obstruction.context of total obstruction.

11        The primary testThe primary test :differentiates partial obstruction of :differentiates partial obstruction of the lacrimal passages from primary hypersecretion of the lacrimal passages from primary hypersecretion of tears. First, a drop of 2% fluorescein is instilled into the tears. First, a drop of 2% fluorescein is instilled into the conjunctival sac. After about 5 minutes, a cotton-tipped conjunctival sac. After about 5 minutes, a cotton-tipped bud moistened in a local anaesthetic is inserted under the bud moistened in a local anaesthetic is inserted under the inferior turbinate at the nasolacrimal duct opening. The inferior turbinate at the nasolacrimal duct opening. The results are interpreted as follows:results are interpreted as follows:

     aa        PositivePositive: fluorescein recovered from the nose : fluorescein recovered from the nose indicates patency of the drainage system. Watering is due indicates patency of the drainage system. Watering is due to primary hypersecretion and no further tests are to primary hypersecretion and no further tests are necessary.necessary.    bb        NegativeNegative: no dye recovered from the nose indicates : no dye recovered from the nose indicates a partial obstruction (site unknown) or failure of the a partial obstruction (site unknown) or failure of the lacrimal pump mechanism. In this situation the secondary lacrimal pump mechanism. In this situation the secondary dye test is performed immediately.dye test is performed immediately.

The secondary (irrigation) testThe secondary (irrigation) test identifies the probable site of partial identifies the probable site of partial obstruction, on the basis of whether the topical fluorescein instilled for obstruction, on the basis of whether the topical fluorescein instilled for the primary test entered the lacrimal sac. Topical anaesthetic is the primary test entered the lacrimal sac. Topical anaesthetic is instilled and any residual fluorescein washed out. The drainage instilled and any residual fluorescein washed out. The drainage system is then irrigated with saline with a cotton bud under the system is then irrigated with saline with a cotton bud under the inferior turbinate.   inferior turbinate.   

aa        PositivePositive: fluorescein-stained saline recovered from the nose : fluorescein-stained saline recovered from the nose indicates that fluorescein entered the lacrimal sac, thus confirming indicates that fluorescein entered the lacrimal sac, thus confirming functional patency of the upper lacrimal passages. Partial obstruction functional patency of the upper lacrimal passages. Partial obstruction of the nasolacrimal duct is inferred.of the nasolacrimal duct is inferred.

    bb        NegativeNegative: unstained saline recovered from the nose indicates : unstained saline recovered from the nose indicates that fluorescein did not enter the lacrimal sac. This implies partial that fluorescein did not enter the lacrimal sac. This implies partial obstruction of the upper lacrimal passages (puncta, canaliculi or obstruction of the upper lacrimal passages (puncta, canaliculi or common canaliculus) or a defective lacrimal pump.common canaliculus) or a defective lacrimal pump.

Probing and irrigation Probing and irrigation Probing and irrigation are performed only after ascertaining punctal Probing and irrigation are performed only after ascertaining punctal

patency.patency.

     aa    Local anaesthetic is instilled into the conjunctival sac.    Local anaesthetic is instilled into the conjunctival sac.

    bb    The lower punctum is dilated (Fig. 2.5A—next page).    The lower punctum is dilated (Fig. 2.5A—next page).

    cc    A gently curved, blunt-tipped 26-gauge lacrimal cannula on a 2 mL     A gently curved, blunt-tipped 26-gauge lacrimal cannula on a 2 mL saline-filled syringe is inserted into the lower punctum and, whilst keeping saline-filled syringe is inserted into the lower punctum and, whilst keeping gentle stretch laterally on the eyelid, advanced a few mm following the gentle stretch laterally on the eyelid, advanced a few mm following the contour of the canaliculus prior to irrigation (Fig. 2.5B). Failure of the tip of contour of the canaliculus prior to irrigation (Fig. 2.5B). Failure of the tip of the cannula to enter the punctum indicates stenosis or obstruction and the cannula to enter the punctum indicates stenosis or obstruction and further dilatation of the punctum may be needed before patency beyond further dilatation of the punctum may be needed before patency beyond can be established.can be established.

    dd    If irrigation confirms lacrimal obstruction an attempt can be made to     If irrigation confirms lacrimal obstruction an attempt can be made to pass the tip of the cannula into the lacrimal sac, the medial wall of which pass the tip of the cannula into the lacrimal sac, the medial wall of which lies against the bone of the lacrimal fossa.lies against the bone of the lacrimal fossa.

    ee    The cannula can come either to a hard stop or to a soft stop.    The cannula can come either to a hard stop or to a soft stop.

A) Dilatation of the inferior punctum (B) irrigation

A hard stopA hard stop occurs if the cannula enters the lacrimal occurs if the cannula enters the lacrimal sac. It comes to a stop at the medial wall of the sac, sac. It comes to a stop at the medial wall of the sac, through which can be felt the rigid lacrimal bone (Fig. through which can be felt the rigid lacrimal bone (Fig. 2.6A). This excludes complete obstruction of the 2.6A). This excludes complete obstruction of the canalicular system. If the saline passes into the nose, canalicular system. If the saline passes into the nose, when it will be tasted by the patient, a patent lacrimal when it will be tasted by the patient, a patent lacrimal system is present, although it may still be stenosed; system is present, although it may still be stenosed; alternatively there may be subtle lacrimal pump failure. alternatively there may be subtle lacrimal pump failure. Failure of saline to reach the nose is indicative of total Failure of saline to reach the nose is indicative of total obstruction of the nasolacrimal duct. In this situation, obstruction of the nasolacrimal duct. In this situation, the lacrimal sac will become distended during irrigation the lacrimal sac will become distended during irrigation and there will also be reflux through the upper and there will also be reflux through the upper punctum. The regurgitated material may be clear, punctum. The regurgitated material may be clear, mucoid, mucopurulent or frankly purulent, depending mucoid, mucopurulent or frankly purulent, depending on the contents of the lacrimal sac.on the contents of the lacrimal sac.

A soft stopA soft stop is experienced if the cannula stops at or is experienced if the cannula stops at or proximal to the junction of the common canaliculus and proximal to the junction of the common canaliculus and the lacrimal sac, i.e. at the lateral wall of the sac. The the lacrimal sac, i.e. at the lateral wall of the sac. The sac is thus not entered – a spongy feeling is experienced sac is thus not entered – a spongy feeling is experienced as the cannula presses the soft tissue of the common as the cannula presses the soft tissue of the common canaliculus and the lateral wall against the medial wall of canaliculus and the lateral wall against the medial wall of the sac and the lacrimal bone behind it (Fig. 2.6B). the sac and the lacrimal bone behind it (Fig. 2.6B). Irrigation will therefore not cause the sac to distend. In Irrigation will therefore not cause the sac to distend. In the case of lower canalicular obstruction, a soft stop will the case of lower canalicular obstruction, a soft stop will be associated with reflux of saline through the lower be associated with reflux of saline through the lower punctum. Reflux through the upper punctum indicates punctum. Reflux through the upper punctum indicates patency of both upper and lower canaliculi, but patency of both upper and lower canaliculi, but obstruction of the common canaliculus.obstruction of the common canaliculus.

Contrast Contrast dacryocystography dacryocystography

Dacryocystography (DCG) Dacryocystography (DCG)

This is an anatomical investigation involves the injection of radio-opaque contrast medium into the canaliculi involves the injection of radio-opaque contrast medium into the canaliculi

followed by capture of magnified images. The test is usually performed on followed by capture of magnified images. The test is usually performed on both sides simultaneously. A DCG is not necessary if the site of both sides simultaneously. A DCG is not necessary if the site of obstruction is obvious such as in the case of a regurgitating mucocele. It obstruction is obvious such as in the case of a regurgitating mucocele. It should also not be performed in a patient with acute dacryocystitis.  should also not be performed in a patient with acute dacryocystitis.  

          IndicationsIndications

    ••        To confirm the site of lacrimal drainage obstruction, especially To confirm the site of lacrimal drainage obstruction, especially prior to prior to surgery.surgery.

    ••        To diagnose diverticuli, fistulae and filling defects caused by stones or To diagnose diverticuli, fistulae and filling defects caused by stones or tumours.tumours.

TechniqueTechnique

Technique Technique   a    The inferior puncta are dilated.a    The inferior puncta are dilated.

    b    Plastic catheters are inserted into the inferior canaliculi on b    Plastic catheters are inserted into the inferior canaliculi on either side; alternatively the upper puncta may be used.either side; alternatively the upper puncta may be used.

    c    Contrast medium, usually 1–2 mL of Lipiodol, is c    Contrast medium, usually 1–2 mL of Lipiodol, is simultaneously injected on both sides and postero-anterior simultaneously injected on both sides and postero-anterior radiographs are taken.radiographs are taken.

    d    Ten minutes later an erect oblique film is taken to assess d    Ten minutes later an erect oblique film is taken to assess the effect of gravity on tear drainage. Digital subtraction DCG the effect of gravity on tear drainage. Digital subtraction DCG provides a higher quality image capture than conventional.provides a higher quality image capture than conventional.

InterpretationInterpretation       ••        Failure of dye to reach the nose indicates Failure of dye to reach the nose indicates

an anatomical obstruction, the site of which is an anatomical obstruction, the site of which is usually evident (Fig. 2.8B and C).usually evident (Fig. 2.8B and C).    ••    A normal dacryocystogram (Fig. 2.8A) in     A normal dacryocystogram (Fig. 2.8A) in the presence of epiphora suggests either the presence of epiphora suggests either functional obstruction or lacrimal pump failure.functional obstruction or lacrimal pump failure.

(A)(A) Conventional DCG without Conventional DCG without subtraction shows normal filling on both subtraction shows normal filling on both sides; sides;

(B)(B) normal left filling and obstruction at normal left filling and obstruction at the junction of the right sac and the junction of the right sac and nasolacrimal duct; nasolacrimal duct;

(C)(C) digital subtraction DCG shows similar digital subtraction DCG shows similar findings findings

Radiologic criteria of lacrimal pathology

1. Regurgitation of radio-opaque fluid into the conjunctival sac

2. Absence of fluid in the nose 3. Fluctuation of lumen of lacrimal system 4. Irregularity in contrast 5. Deformation involving lacrimal sac

Nuclear lacrimal Nuclear lacrimal scintigraphy scintigraphy

This is a non invasive physiological test. Scintigraphy is a sophisticated test which assesses tear drainage Scintigraphy is a sophisticated test which assesses tear drainage

under more physiological conditions than DCG. Although it does under more physiological conditions than DCG. Although it does not provide the same detailed anatomical visualization as DCG, it not provide the same detailed anatomical visualization as DCG, it is more sensitive in assessing incomplete blocks. It is also useful is more sensitive in assessing incomplete blocks. It is also useful in assessing physiological obstruction beyond the sac. in assessing physiological obstruction beyond the sac. The test is performed as follows: The test is performed as follows:

    aa    Radionuclide technetium-99 is delivered by a micropipette to     Radionuclide technetium-99 is delivered by a micropipette to the lateral conjunctival sac as a 10 µl drop. The tears are thus the lateral conjunctival sac as a 10 µl drop. The tears are thus labelled with this gamma-emitting radioactive substance.labelled with this gamma-emitting radioactive substance.

    bb    The tracer is imaged by a gamma camera focused on the     The tracer is imaged by a gamma camera focused on the inner canthus and a sequence of images is recorded over 45–60 inner canthus and a sequence of images is recorded over 45–60 minutes (Fig. 2.8D).minutes (Fig. 2.8D).

(D)(D) nuclear lacrimal scintigraphy shows nuclear lacrimal scintigraphy shows passage of tracer in the right lacrimal passage of tracer in the right lacrimal system but obstructed drainage in the left system but obstructed drainage in the left nasolacrimal ductnasolacrimal duct

Computed tomography and MRI

Computed tomography (CT) can be helpful in assessing the structures intimately associated with the nasolacrimal drainage system. The CT scanning is used mainly when an extrinsic disease is suspected and is of great help to the patients with paranasal sinus or facial pathology associated with the lacrimal system (tumor, rhinosinusitis, facial trauma,following facial surgery, etc.)

Magnetic resonance is not used in practice in lacrimal diagnostics and is reserved only for the special cases, e.g., for differentiation of masses of the lacrimal sac.