The Lacrimal Drainage System

Anatomy Of The Lacrimal Gland

• It consists of an upper lid and a lower lid with two puncta: upper and lower punctum.
• The upper and lower canaliculi join to form common canaliculi, which open into the lacrimal sac and open into the nasolacrimal duct.

• The punctum divides the eyelid into pars lacrimalis (one-sixth of the part without eyelashes) and pars ciliaris (five-sixth of the portion with eyelashes).
• The length of the Naso-lacrimal duct varies from 17-18mm.
• Length of ampulla – 2mm.
• The valve of Rosen muller is present between the common canaliculi and lacrimal sac.
• The Hasner valve is present in the NLD (nasolacrimal duct) just before the opening of the inferior meatus.
• The nasolacrimal duct opens into the Anterior portion of the inferior- meatus of the nose.
• The upper puncta is medial to the lower puncta.

Also Read: Retina Of The Eye

Physiology Of The Lacrimal Gland

• The tear is formed from lacrimal gland i.e., accessory lacrimal gland and main lacrimal gland.
• It lubricates the ocular surface. After lubricating, some are evaporated, and some tears are drained.
• Blinking plays an important role in the drainage of the tear.

• When the eyes are open, negative pressure in the lacrimal sac expands. 
• Due to the negative pressure and capillary forces, the tear flows from the puncta to the canaliculus.
• Now, when we close our eyes, the positive pressure developed in the lacrimal sac pushes the tear into the nasolacrimal duct.

Types Of Watering

Examination

Meniscus Height Of The Tear

• Under the slit lamp, check the meniscus height of the tear film.
• The height of the lower meniscus has increased (the normal height is 0.2-0.4mm).
• If there is drainage blockage it can go up to 0.6mm.

Conjunctivochalasis

• It is a loose conjunctiva that is not properly attached.
• It covers the puncta, and the tear cannot drain.

Lacrimal Puncta

• Check for Stenosis of the puncta.
• Malposition of the puncta
• If there is pouting, it is a sign of canaliculitis.

Caruncle

• Large caruncle which obstructs the puncta.

Regurgitation Test

• Press the medial canthus at the sac area. If the nasolacrimal duct is blocked, regurgitation occurs.

Investigation

1. Fluorescein Disappearance Test
   • Fluorescein is put in the eye and waited for 5 to 10 minutes.
   • If fluorescein is present, there is some drainage issue in the eye.
   • Fluorescein clearance test: 
   • To assess the tear turnover for dry eye.
   • It is a test for dry eye where 5 microlitres of flourescein is added in the eye.
   • We check how much flourescein is retained in the eye after five minutes.
2. Syringing 
   • We dilate the puncta with a dilator.
   • With a 26-gauge blunt tip needle, insert it into the sac.
   • Check whether you observe a hard or soft stop.
   • If it is a hard stop, then the canaliculi are normal.
   • If it is a soft stop, then there is an issue with the common canaliculi or lower canaliculi.
   • If lower canaliculi are blocked, it regurgitates from the lower puncta.
   • If the common canaliculi are blocked, it regurgitates from both the puncta.
   • During the hard stop,

• If there is a hard stop with doubt of partial obstruction or pump failure, or punctual obstruction, the Jones dye test is done.

3. Jones Dye Test

• The primary test differentiates it from hypersecretion.                                               
• Fluorescein is put in the conjunctival sac, and we wait for five minutes.
• Cotton soaked with anaesthetic is put in the inferior turbinate of the nose.
• If fluorescein is present in the cotton, the inference is that it is a case of hypersecretion.
• False- positive is high in this test.
• The oropharynx is checked with cobalt blue light to countercheck the negative.
• If it is negative, we perform the secondary test.
• After washing off the fluorescein, saline is injected into the conjunctiva sac.
• There is either fluorescein-stained saline or only plain saline coming out of the nose. 
• Fluorescein-stained saline indicates that fluorescein has entered the tract and this suggests that the upper lacrimal passage is normal. There may be partial obstruction of NLD distal to the sac.
• If no fluorescein is present in the saline, then the fluorescein has not entered the lacrimal sac. The upper lacrimal passage has an obstruction.
  • There is either a partial physical obstruction or pump failure. 

4. Dacryocrystography (DCG TEST)

• Detailed study of the lacrimal sac
• The radiopaque contrast is ethiodized oil.
• The oil is injected into the canaliculi and the magnified images are taken.
• Tumours or stones in the sac are found using this method.

5. Dacryoscintillography Or Nuclear Lacrimal Scintigraphy

• Labelling the tear with a radioactive substance.
• Studying the flow of tears in physiological conditions.
• This is the IOC for lacrimal pump failure.
• investigation of choice for lacrimal pump failure: Dacryoscintillography

6. CT/ MRI Scan

• Pathology of the lacrimal sac
• Paranasal sinuses

Also Read: Refractive Errors: Types, Symptoms and Treatment

Obstruction Of Lacrimal Pathway

Congenital Lacrimal Pathway Obstruction

1. Nasolacrimal duct obstruction
2. Dacryocele

Acquired lacrimal pathway obstruction

1. Conjuctivochalasia
2. Lacrimal punctal stenosis: Primary (no punctal eversion) or secondary (Punctal eversion)
3. Canalicular obstruction
4. Dacryolithiasis

Dacryocystitis

It is the inflammation of the lacrimal sac.

Congenital Dacryocystitis

• Causes of Congenital Dacryocystitis: Non-canalisation of the NLD
• Symptoms of Congenital Dacryocystitis: Child with Epiphora or discharge
• Investigations for Congenital Dacryocystitis: Fluorescein disappearance test or Regurgitation test
• Differential Diagnosis of Congenital Dacryocystitis:
  • Congenital glaucoma
  • Neonatal conjunctivitis 
  • Punctal atresia
• Treatment of Congenital Dacryocystitis:
  • If the patient is less than 9 months old, a Crigglers massage is performed. The hydrostatic pressure of the nasolacrimal duct is increased. The maximum success of Crigglers massage is within 6 months of age.
  • If the patient is greater than 9 months, probing is done. The Bowman’s probe is pushed down the lacrimal duct. The success rate is till 18 months (2 years)
  • If the child is greater than 4 years, DCR (dacryocystorhinostomy) surgery is done.
  • Another new modality of treatment is intubation and balloon dilatation of NLD.
• While performing the DCR surgery,  the opening is made in the Middle meatus.
• Types of DCR:
  • External DCR
  • Endonasal DCR
  • Endonasal Laser DCR
  • Trans canalicular laser DCR
  • The laser used is diode: 980nm or Holmium-YAG laser

Congenital Dacryocele

• Cause of Congenital Dacryocele: Amniotic fluid and mucous is trapped in the lacrimal sac.
• Symptoms of Congenital Dacryocele:
  • Bluish cystic swelling
  • Epiphora
• Treatments of Congenital Dacryocele:
  • Antibiotics
  • Probing

Acute Acquired Dacryocystitis

• The most common etiological agent of acute dacryocystitis is Staph Aureus or Streptococcus
• Symptoms of Acute Acquired Dacryocystitis:
  • Epiphora
  • Discharge
  • All signs of inflammation, like redness, pain and tenderness.
• This acute inflammation may lead to lacrimal abscess or pre-septal cellulitis.
• If any drainage is done, it may lead to Lacrimal fistula formation.
• Treatment of Acute Acquired Dacryocystitis:
  • Conservative treatment with Antibiotics/ anti-inflammatory
  • DCR

Chronic Acquired Dacryocystitis

• More common in females than males.
• MC aetiology: Staph aureus
• C/F: epiphora, discharge, and mucocele
• Symptoms are the same as those of acute acquired dacryocystitis.
• Sequelae:
  • Mucocoele formation can lead to Pyocoele formation which can lead to lacrimal fibrosis.
• Treatment of Chronic Acquired Dacryocystitis:
  • Treatment for lacrimal fibrosis is DCT(Dacryocystectomy).

Canaliculitis

• Causes of Canaliculitis
  • Actinomyces Israeli
  • Herpes simplex virus
• Symptoms of Canaliculitis
  • Pouting of puncta (Hallmark of canaliculitis)
  • Concretions inside canaliculi ? that get complicated as canalicular obstruction.
• Treatment of Canaliculitis
  • Broad-spectrum antibiotics
  • Canaliculotomy: give linear incision and curettage the concreations.

It is important to learn the lacrimal drainage as it is a very common ailment presented in the pediatric OPD and would really help young doctors to make up a diagnosis. This topic can also be asked in the NEET-PG/ FMGE examinations. It is recomended you watch our detail video on this topic from the prepladder app.

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