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Orbit, Eyelids, and Lacrimal System > Lacrimal System > Flashcards

Lacrimal System Flashcards

1
Q

what type of gland is the lacrimal gland

A

exocrine

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2
Q

what divides the two lobes of the lacrimal gland, and what are the two lobes?

A

lateral horn of the levator aponeurosis divides orbital and palpebral lobes

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3
Q

where should biopsy of the lacrimal gland be performed, and why?

A

orbital (because palpebral gland has lacrimal ducts running through it which can be damaged by biopsy)

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4
Q

what types of glands are Krause and Wolfring, and where are they located

A

both exocrine glands; Krause in the fornices, Wolfring at superior border of tarsus

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5
Q

name components of lacrimal drainage system in order

A

punctum, canaliculus, common canaliculus, lacrimal sac, valve of Rosenmuller, NLD, valve of Hasner, inferior meatus

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6
Q

what is another name for the posterior medial canthal tendon, and where does it attach

A

Horner muscle, attaches to posterior lacrimal crest

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7
Q

length of NLD

A

12-18 mm

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8
Q

which muscle is responsible for active pumping of most of the tear flow

A

orbicularis oculi

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9
Q

most common location of lacrimal cutaneous fistula

A

infranasal to medial canthus

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10
Q
  • constant tearing suggests___
  • constant tearing w/ mucopurulent discharge suggests ___
  • intermediate tearing w/ mucopurulent discharge suggests ___
A
  • canalicular obstruction
  • complete NLD obstruction
  • intermittent NLD obstruction
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11
Q

most common cause of congenital obstruction of the lacrimal drainage system?

A

membrane blocking valve of Hasner; 90% resolve spontaneously by 1 year

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12
Q

length and direction of canaliculus

A

2mm inferior, then bends for 8-10mm medial

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13
Q

soft stop on probing?

hard stop?

A

soft - usually obstruction

hard - usually kink in canaliculus created by bunching of tissues

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14
Q

management of congenital NLD obstruction

A
  • start conservative: observation, lacrimal sac massage, topical or oral abx
  • then probe if not resolved (90% will be cured with probing)
  • stent if residual obstruction, use silicone stent (example: Crawford stent); 70% success rate
  • balloon dacroplasty can be performed for refractory cases
  • DCR is definitive management for refractory cases
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15
Q

intermittent epiphora and mucoid discharge from punctum, especially when associated with cold-like symptoms. probing reveals inferior turbinate lateralized against the NLD. treatment?

A

medial infracture of the inferior turbinate

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16
Q

small, nontender, slighlty bluish bump infranasal to medial canthus in newborn

A

dacrocystocele. treat like regular NLD obstruction

17
Q

normal tear break-up time? what does abnormal value suggest?

A

10 seconds or more; abnormal suggests deficient mucin or lipid layer of tears

18
Q

Steps to Schirmer test, and what is abnormal value?

A

apply topical anesthetic. place strip in inferior fornix for 5 minutes. abnormal is 15 mm

19
Q

abnormal dye disappearance test?

A

persistence of sye past 5 minutes

20
Q

reflux of saline from same canaliculus during irrigation? from opposite canaliculus? reflux of mucus?

A

same: canalicular obstruction
opposite: common canalicular obstruction
mucus: NLD obstruction

21
Q

utility of NLD probing in kids v adults

A
  • kids: useful b/c NLD obstruction usually due to thin membrane over valve of Hasner which can be fixed w/ probing
  • adults: not useful b/c NLD obstruction usually 2/2 scarring which cannot be probed. irrigation is used for adults
22
Q

treatment for punctal stenosis?

A

dilation for first line although has short lived effects. most patients will need punctoplasty (snipping small portion of ampulla). stenting for refractory cases

23
Q

most common cause of enlarged puncta? how do these patients present?

A

iatrogenic (stenting, punctoplasty). present w/ epiphora (impaired punctal seal prevents negative pressure in lacrimal sac and therefor tears are not sucked through canaliculi effectively)

24
Q

causes of acquired canalicular obstruction

A

trauma, punctal plug issues, chemo, infection, ocular cicatricial pemphigoid, Stevens-Johonson, graft-v-host, neoplasm

25
Q

CanaliculoDCR v ConjunctivoDCR v DCR

A

CanaliculoDCR: enter through canalicular system, resect obstructed segment, and anastamose canaliculus to lacrimal sac or lateral nasal wall mucosa

ConjunctivoDCR: bypass created from caruncle to new hole in nose (rhinostomy)

DCR: creation of anastamosis of lacrimal sac to nasal cavity through bony ostium

26
Q

causes of acquired NLD obstruction

A

involutional stenosis, dacrolith, sinus disease, trauma, inflammatory disease, lacrimal plogs, radioactive iodine, neoplasm

27
Q

treatment of choice for most patients with acquired NLD obstruction

A

DCR

28
Q

benefits of endonasal DCR v external DCR

A

endonasal: less discomfort, no visible scar, quicker recovery

29
Q

timing of repair of traumatic canalicular injury

A

ASAP, w/in 48 hours

30
Q

effects of having only one functional canaliculus?

A

50% get intermittent or constant epiphora

31
Q

utility of direct suturing of severed canaliculi ends back together?

A

usually not useful; using a lacrimal stent and restoring normal anatomy of surrounding tissues is suffiecient

32
Q

in the absence of complications, how long are stents generally left in after traumatic canalicular repair?

A

2 months

33
Q

most common viral cause of dacroadenitis

A

EBV

34
Q

most common cause of infectious canaliculitis

A

Actinomyces israelii

35
Q

initial treatment of canaliculitis

A

warm compresses, massage, topical or oral abx. curettage or canaliculotomy for refractory cases

36
Q

approach to canaliculotomy for canaliculitis

A

conjunctival approach, only to horizontal portion, then leave open to heal by secondary intention

37
Q

most common cause of dacrocystitis

A

complete NLD obstruction

38
Q

management of acute dacrocystitis

A
  • intubation and stenting are NOT recommended
  • topical abx NOT useful
  • oral abx most useful (GP bacteria, but suspect GN in diabetics and immunocompromised)
  • I&D as needed for an abscess. IV abx for severe cases
  • DCR is definitive treatment to prevent recurrence. this should be performed before elective intraocular surgery

Orbit, Eyelids, and Lacrimal System (14 decks)

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