Nasolacrimal Duct Obstruction

Nasolacrimal Duct Obstruction

Neonates do weird things. Some of these things are normal… and some are not. While it is true, that you should “never trust a neonate” (See ALTE / BRUE), there are sometimes when the odd is not cause for tremendous turmoil. One example is those pesky clogged tear ducts. Let’s take a moment to consider Nasolacrimal Duct Obstruction:

Nasolacrimal Duct Obstruction: Anatomy

  • Tear ducts are complicated (as is much of the human body).
    • Lacrimal System consists of: [Orge, 2014]
      • Lacrimal Gland – an exocrine gland with 2 lobes nestled in the frontal bone
      • Lacrimal ducts – secrete the aqueous portion of tears
      • Accessory Lacrimal Glands of Krause and Wolfring – located within the conjunctival fornices
      • Puncta – located on the nasal corner of the upper and lower eyelids; serves as the exit point for tears
      • Ampulla – extend vertically from each puncta
      • Canaliculi – extend perpendicularly to the ampulla and meet to form the common canaliculus, which open into the lacrimal sac medially.
      • Lacrimal Sac – runs vertically
      • Nasolacrimal Duct – connects lacrimal sac to nasal cavity as it empties into the inferior nasal meatus (why your nose runs when you cry)
      • Valve of Hasner – a mucosal flap that separates nasal cavity from the nasolacrimal duct; one way valve.
    • Tear Drainage is also complex: [Orge, 2014]
      • Tears do not simply drain by gravity.
      • Opening and closing the eyes (AKA, Blinking), literally, generates both negative and positive pressures within the system that pumps tears through it.

Lacrimal System: What Can Go Wrong

  • Congenital Nasolacrimal Duct Obstruction [Orge, 2014]
    • Nasolacrimal Duct Obstruction (NLDO) is the most common lacrimal system problem.
    • Occurs in ~6% of all newborns!
    • Incomplete canalization of the nasolacrimal duct creating an imperforate Valve of Hasner is a common cause.
    • Infants present after tear production matures (~6 weeks of life).
    • Presents as increased tearing, matted eyelashes, mucoid discharge from tear stasis.
    • Distinguished from conjunctivitis as there is no light sensitivity and no bulbar conjunctiva redness (the eyes are still white).
    • “Dye Disappearance Test” can help also:
      • Normally, fluorescein stained tears should disappear within 5 minutes as the tears eventually flow away.
      • With Nasolacrimal Duct Obstruction, the stained tears persist.
    • Treated with:
      • Digital massage in a downward motion starting from the puncta toward the lacrimal sac and nasolacrimal duct. Increased pressure my open the obstructed valve.
      • Occasional topical antibiotic drops to help control the bacterial overgrowth in the stagnant tear pool (sounds like name of a 80’s grunge band).
      • Occasionally, surgery / procedure is required to open the obstruction and may done endoscopically or even be done in the office setting. [Galindo-Ferreiro, 2016; Miller, 2014; Lee, 2012]
  • Congenital Dacryocystocele [Orge, 2014]
    • Present as a bluish mass overlying the area of the lacrimal sac or below the medial canthus.
    • Noted soon after birth.
    • Is an out-pouching of the lacrimal sac and duct.
    • Associated with increased tearing, local inflammation, local infection, and cysts.
    • May cause respiratory distress if it is bilateral (as neonates are obligatory nasal breathers).
    • Often resistant to conservative therapy. Start with massage and topical antibiotics, but surgery may be needed.
  • Dacryocystitis [Orge, 2014]
    • Infection of the Lacrimal Sac.
    • Most commonly due to chronic tear stasis from Congenital Nasolacrimal Duct Obstruction
    • Distinguished by erythema and swelling below the medial cantonal area.
    • May be painful, but can also be painless.
    • Treat with warm compresses and oral antibiotics (against Strep and Staph).
    • Surgical drainage and repair is rarely needed.
  • Dacryoadenitis [Orge, 2014]
    • Inflammation of the Lacrimal Gland.
    • May be due to noninfectious reasons – malignancy
    • May be due to infectious reasons – EBV, Tuberculosis, local trauma related infection
  • Canaliculitis [Orge, 2014]
    • Infection of the canaliculus by viruses, bacteria, or fungi.
    • Mucopurulent conjunctivitis and drainage are seen.
    • Compression of the canaliculus can express more purulent material (gross).
    • There is no lacrimal sac distention like in dacrocystitis.
    • Treat with warm compresses, digital massage, and antibiotics (topical may be effective alone).
    • Occasionally need punctual curettage to remove stone.
  • Acquired Punctal or Canalicular Stenosis [Orge, 2014]
    • Acquired stenosis may result from viral infections (like varicella).
    • Trauma and localized masses can also obstruct the delicate drainage system.

Moral of the Morsel

  • The human body is complex in almost every detail! Simple tear production and management isn’t all that simple really.
  • Not everyone cries. Especially Neonates… may take up to 6 weeks before they develop the ability to make tears!
  • Not all matted lashes are due to conjunctivitis! Think about clogged tear ducts and recommend gentle massage.

References

Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renowned educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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