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HNS42 Orbit Flashcards

1
Q

***Contents of the orbit

A
  1. Eyeball
    - 1/5 of orbit
  2. Muscles
    - Recti x4
    - Oblique x2
    - Levator palpebrae superioris
    - Superior tarsal muscle (Muller’s muscle)
  3. Nerves
    - CN2, 3, 4, 6
    - CNV1 (Lacrimal, Frontal, Nasociliary)
    - CNV2 (Infraorbital, Zygomatic)
  4. Vessels
    - Ophthalmic artery and branches (ICA)
    - Infraorbital vessels (ECA —> Maxillary)
    - Middle meningeal artery and branches (Maxillary)
    - Superior + Inferior Ophthalmic vein
  5. Orbital fat, Reticular tissue, Orbital fascia
  6. Lacrimal gland + Lacrimal sac
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2
Q

Anatomy of eyeball

A

Anterior segment:

  1. Conjunctiva (anterior covering Sclera)
  2. Iris
  3. Lens (controlled by Ciliary body)
  4. Pupil
  5. Cornea
  6. Anterior chamber (anterior to iris, drainage of aqueous through trabecular meshwork)
  7. Ciliary body (production of aqueous —> posterior chamber —> anterior chamber)
  8. Posterior chamber (behind iris)

Posterior segment:

  1. Vitreous body
  2. Macula (concentration of cone cells)
  3. Retina
  4. Choroid (pack of blood vessels)
  5. Optic nerve
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3
Q

***Arterial supply of eyeball

A

Internal carotid artery —> Ophthalmic artery —>

  1. Retinal artery
  2. Posterior ciliary arteries (Long + Short)
  3. Muscular artery —> Anterior ciliary arteries

Anterior segment:
1. Iris + Ciliary body:
—> **Long Posterior ciliary artery (through choroid) anastomose with **Anterior ciliary artery (through extraocular muscles)
—> Minor arterial arcade + Major arterial arcade (trauma: Hyphema)

  1. Sclera + Conjuntiva + Iris
    —> ***Anterior ciliary artery

Posterior segment:

  1. Retina —> ***Retinal artery (within RNFL Retina Nerve Fibre Layer)
  2. Choroid —> **Long (anterior to equator)+ **Short Posterior ciliary artery (posterior to equator)
    - ***Dual circulation —> Retina and Choroidal circulations are separate circulations
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4
Q

Central retinal artery

A
  • Supply retina
  • Pierce Dural sheath of optic nerve 12 mm behind the globe
  • Gives off small meningeal branches to supply Pial sheath of optic nerve

**Clinical relevance: **Central retinal artery occlusion
—> Retinal circulation occluded by emboli
—> Choroidal circulation unaffected
—> **Cherry red spot at fovea (unaffected Choroidal circulation) in middle of **Pale retina (occluded Retinal circulation) (oedematous retina due to ischaemia)

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5
Q

Ciliary arteries

A

Major blood supply of globe

  1. Long Posterior ciliary artery
    - paired arteries that pierce sclera outside the circle of Zinn and travel forward in suprachoroidal space to **Ciliary body
    - gives recurrent branches that supply **    Choroid anterior to equator and anastomose with Short Posterior ciliary artery
  2. Short Posterior ciliary artery
    - 10-20 branches pierce sclera around optic nerve (i.e. at the back)
    - anastomotic circle of Zinn supply optic nerve head (Optic disc)
    - supply ***Choroid posterior to equator (posterior 2/3 Choroid)
  3. Anterior ciliary artery
    - 7 arteries —> 2 for each **rectus muscle except Lateral Rectus (only 1)
    - supply **    Sclera + **Conjuntiva + **Iris
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6
Q

Anterior segment

A
  1. Long Posterior ciliary artery
  2. Anterior ciliary artery
    —> Iris + Ciliary body
  • Iris vessels: Non-fenestrated (endothelial tight junctions)
  • Ciliary body vessels: ***Fenestrated (NO tight junctions) —> allow production of aqueous humour
  • ***Blood aqueous barrier (tight junctions in ciliary epithelium + iris endothelium to prevent substances going into eye)
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7
Q

Posterior segment

A
  1. Retina: ***Retinal artery
    - 10 layers:
    —> Inner 2/3: Central retinal artery
    —> Outer 1/3 (beyond Outer Plexiform Layer): Watershed area (diffusion to get nutrients) —> Foveal avascular zone: absent capillaries over fovea (highest concentration of cone cells) —> age-related macular degeneration
  2. Choroid: ***Long + Short Posterior ciliary artery
    - Short Posterior ciliary artery: posterior to equator
    - Long Posterior ciliary artery: anterior to equator
  • **Blood retinal barrier:
  • Tight junction between Retinal Pigment Epithelium
  • Separate retinal circulation from choroidal circulation —> prevent substances going into eye
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8
Q

***Blood aqueous barrier + Blood retinal barrier

A
  • **Blood aqueous barrier:
  • Tight junctions in ciliary epithelium + iris endothelium to prevent substances going into eye
  • **Blood retinal barrier:
  • Tight junction between RPE (retinal pigment epithelium) of retina
  • Separate retinal circulation from choroidal circulation —> prevent substances going into eye
  • Immune privileged site: Part of the brain but exposed to outside
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9
Q

***Venous drainage of eye

A
  1. Retina: ***Central retinal vein
  2. Choroid: 4 Vortex veins (2 superior, 2 inferior)
    - exit eyeball posterior to equator
    - **Superior Vortex veins —> Superior Ophthalmic vein / Cavernous sinus
    - **    Inferior Vortex veins —> Inferior Ophthalmic venous plexus / Cavernous sinus
    - Central retinal vein
    - Supraorbital vein
    - Facial vein

Clinical relevance:

  1. Cavernous sinus thrombosis (infection of orbit —> proptosis)
  2. Central retinal vein occlusion (haemorrhage of retina due to blockage of drainage)
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10
Q

***Orbit

A

4 walls from 7 bones:

  1. Ethmoid
  2. Frontal
  3. Lacrimal
  4. Maxillary
  5. Palatine
  6. Sphenoid
  7. Zygomatic

Anatomical space boundary:

  • Superior: Anterior cranial fossa
  • Inferior: Maxillary sinus
  • Medial: Nasal cavity + Ethmoidal air cells
  • Lateral: Middle cranial fossa
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11
Q

Superior wall

A

Triangular shape

Bones:

  1. Frontal bone (anterior)
  2. Lesser wing of sphenoid (posterior)
Relations:
- Above:
—> Frontal lobe + meninges
- Below:
—> Periorbita, Frontal nerve, Trochlear nerve, LPS, SR, SO, Lacrimal gland

Anterior + Posterior Ethmoidal canals: present at junction of roof + medial wall

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12
Q

Inferior wall / Floor

A

Triangular shape, Shortest

Bones:
1. Maxillary bone (medial)
2. Zygomatic bone (lateral)
3. Palatine bone (posterior)
—> ***Inferior orbital fissure separate posterior part of floor from lateral wall

Infraorbital nerve + vessels:
- Inferior orbital fissure —> groove —> canal —> Infraorbital foramen

Relations:
- Below:
—> Mamillary + Palatine air sinus
- Above:
—> Inferior oblique muscle + Rectus muscle + Nerve to Inferior oblique muscle

Clinical relevance:
- Orbital blow-out fracture —> floor fracture —> can damage Infraorbital nerve

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13
Q

Medial wall

A

Quadrangular shape

Bones:

  1. Frontal process of maxilla
  2. Lacrimal bone
  3. Orbital plate of ethmoid
  4. Sphenoid body

Lacrimal fossa (Maxilla + Lacrimal bone):

  • Anterior lacrimal crest = Maxilla
  • Posterior lacrimal crest = Lacrimal bone
Relations:
- Medial:
—> Anterior, Middle, Posterior Ethmoid sinus
—> Middle meatus
- Orbital surface related to Superior oblique + Medial rectus:
—> Anterior + Posterior ethmoid nerve
—> Intratrochlea nerve
—> Terminal branch of ophthalmic artery
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14
Q

Lateral wall

A

Triangular shape

Bones:

  1. Zygomatic bone (anterior)
  2. Greater wing of sphenoid (posterior)
Relations:
- Lateral:
—> Temporal fossa (anterior)
—> Middle cranial fossa (posterior)
- Medial:
—> Lateral Rectus muscle
—> Lacrimal nerves + vessels
—> Zygomatic nerves and their communication
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15
Q

Apex of orbit

A
  1. Superior orbital fissure
    - CNV1 (Lacrimal + Frontal)
    - CN4
  2. Inferior orbital fissure
    - CNV2 (Zygomatic)
    - Infraorbital nerve
  3. Optic canal
    - Optic nerve
  4. Annulus of Zinn (origin of most extraocular muscles)
    - CN3 (superior + inferior)
    - CNV1 (Nasociliary)
    - CN6
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16
Q

Thyroid eye disease

A

Inflammation of ocular muscles —> Enlarged

  1. Proptosis + Diplopia
  2. Compress CN2 at apex —> Vision loss
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17
Q

Arterial supply of orbit

A

Internal carotid artery —> Ophthalmic artery —>

  1. Anterior + Posterior Ethmoidal artery
  2. Supratrochlear artery
  3. Supraorbital artery
  4. Lacrimal artery
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18
Q

Venous drainage of orbit

A

Posterior:
- Cavernous sinus + Deep facial vein

Anteromedial:

  • Ophthalmic vein
  • Angular vein

Anterolateral:
- Superficial temporal vein

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19
Q

***Innervation of orbit

A

CNV1 —> Medial part:

  1. Supraorbital nerve
  2. Supratrochlear nerve

CNV2 —> Lateral + Inferior part:

  1. Infraorbital nerve
  2. Zygomatic nerve
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20
Q

Ocular alignment of extraocular muscles

A

Globe not in parallel with axis of orbit

Synchronous ocular movement is performed by 6 extraocular muscles in each orbit (Rectus x4, Obliques x2)
—> Muscles controlled by brainstem via CN3, 4, 6

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21
Q

Rectus muscle

A

Pierce Tenon’s capsule —> insert into Sclera in front of equator

Blood supply:
Anterior ciliary artery
- 7 arteries —> 2 for each ***rectus muscle except Lateral rectus (only 1)
1. Medial muscular artery —> Medial, Inferior rectus
2. Lateral muscular artery —> Lateral, Superior rectus

Nerve:

  1. CN3 —> Medial, Superior, Inferior rectus
  2. CN6 —> Lateral rectus

(Superior rectus: Complex with Levator palpebrae superioris
—> allow retraction of eyelid when eye elevate
Inferior rectus: Complex with Lower lid retractor)

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22
Q

Superior oblique + Inferior oblique muscles

A

Blood supply:

  1. Medial muscular artery: Inferior oblique
  2. Lateral muscular artery: Superior oblique

Nerve supply:

  1. CN4: Superior oblique (***Contralateral)
  2. CN3: Inferior oblique

Inferior oblique: only muscle NOT from Annulus of Zinn, originate from Anterior orbit!!!

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23
Q

Actions of extraocular muscles

A

Medial rectus: Adduction (向內望)
Lateral rectus: Abduction (向外望)

Superior rectus: Elevation (+ adduction, intorsion)
Inferior rectus: Depression (+ adduction, extorsion)

Superior oblique: Intorsion (向內擰) (+ abduction, depression)
Inferior oblique: Extorsion (向外擰) (+ abduction, elevation)

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24
Q

Suspensory ligament of eyeball

A

Connect between extraocular muscle

—> allow eyeball to float within orbit

25
Q

Synchronous eye movement

A

Brainstem coordinates conjugate eye movement
—> Activate Lateral + Medial rectus on 2 eyeballs
—> Inhibit Antagonist of each eyeball

Fusion reflex ensures images on both retina area similar
—> Brain becomes confused when eyes are focused on different objects
—> Diplopia

26
Q

Image stabilisation

A

Images remains stable even if the viewer / subject is moving, rely on:

  1. Proprioception input
  2. Vestibular input
  3. Smooth pursuit eye movement
  4. Saccadic eye movement
  5. Higher processing
27
Q

Eyelids

A
  1. Thin fold of skin —> covers and protects eye
    - thinnest skin in whole body
    - fine row of eyelashes —> protect from dust, foreign body, perspiration
  2. Regularly spread tears, other secretions —> keep eye moist
  3. Corneal + Menace reflex —> protect eye from foreign body
28
Q

Anatomy cross section of eyelid

A

Above lid crease

  1. Skin
  2. Orbicularis muscle
  3. Orbital septum
  4. Orbital fat (behind orbital septum)
  5. Levator aponeurosis tendon
  6. Superior tarsal muscle (innervated by sympathetic NS)
  7. Conjunctiva

Below lid crease

  1. Skin
  2. Orbicularis muscle
  3. Tarsal plate (maintain shape + secrete oily substance)
  4. Conjunctiva
29
Q

Periorbital fat

A

Upper lid:

  1. Medial (nasal)
  2. Preaponeurotic pre-Levator fat pad
  • divided by:
    —> Medial horn of Levator aponeurosis
    —> Lateral fascia on superior oblique muscle

Lower lid:

  1. Lower medial fat pad
    - separated by inferior oblique
  2. Lower central fat pad
    - separated by Arcuate expansion of inferior oblique
  3. Lower lateral fat pad
30
Q

Asian vs Western eyelid

A
  • Fibres vs Fat position
  • Created by anterior insertion of Levator aponeurosis
  • Attachments prevent descent of orbital fat —> Lid crease
31
Q

Blood supply of eyelids

A
  1. Medial Palpebral artery (from Ophthalmic artery) —> supply medial part
  2. Lateral Palpebral artery (from Lacrimal artery) —> supply lateral part

Palpebral arteries (from ICA) anastomose with **Facial artery (ECA) and its branch (Zygomatico-temporal artery + Angular artery)
—> at lateral aspect of lid
—> form **Marginal + Peripheral Palpebral arcades

32
Q

Venous drainage of eyelid

A

Superior + Inferior Palpebral vein

—> Angular vein + Facial vein etc.

33
Q

Lacrimal gland + Nasolacrimal duct

A 
Blinking causes tear to travel and distribution of tears over the globe
—> Superior + Inferior papilla
—> Superior + Inferior canaliculi
—> Common canaliculus
—> Drain / suck into Lacrimal sac
—> Nasolacrimal duct
—> Inferior meatus
34
Q

After this slide is exam-related notes

A

After this slide is exam-related notes

35
Q

Anatomy of eyeball

A

Anterior segment:

  1. Conjunctiva (anterior covering Sclera)
  2. Iris
  3. Lens (controlled by Ciliary body)
  4. Pupil
  5. Cornea
  6. Anterior chamber (anterior to iris, drainage of aqueous through trabecular meshwork)
  7. Ciliary body (production of aqueous —> posterior chamber —> anterior chamber)
  8. Posterior chamber (behind iris)

Posterior segment:

  1. Vitreous body
  2. Macula (concentration of cone cells)
  3. Retina
  4. Choroid (pack of blood vessels)
  5. Optic nerve
36
Q

***Blood aqueous barrier + Blood retinal barrier

A
  • **Blood aqueous barrier (前面):
  • Tight junctions in ciliary epithelium + iris endothelium to prevent substances going into eye
  • **Blood retinal barrier (後面):
  • Tight junction between RPE (retinal pigment epithelium) of retina
  • Separate retinal circulation from choroidal circulation —> prevent substances going into eye
  • Immune privileged site: Part of the brain but exposed to outside
37
Q

***Arterial supply of eyeball

A

Internal carotid artery —> Ophthalmic artery —>

  1. ***Retinal artery
  2. ***Posterior ciliary arteries (Long + Short)
  3. Muscular artery —> ***Anterior ciliary arteries

Anterior segment:
1. Iris + Ciliary body:
—> **Long Posterior ciliary artery (through choroid) anastomose with **Anterior ciliary artery (through extraocular muscles)
—> Minor arterial arcade + Major arterial arcade (trauma: Hyphema)

  1. Extraocular muscles + Sclera + Conjuntiva + Iris
    —> ***Anterior ciliary artery

Posterior segment:

  1. Retina —> ***Retinal artery (within RNFL Retina Nerve Fibre Layer)
  2. Choroid —> **Long (anterior to equator) + **Short Posterior ciliary artery (posterior to equator)
    - ***Dual circulation —> Retina and Choroidal circulations are separate circulations
38
Q

***Venous drainage of eyeball

A
  1. Retina: ***Central retinal vein
  2. Choroid: 4 Vortex veins (2 superior, 2 inferior)
    - exit eyeball posterior to equator
    - **Superior Vortex veins —> Superior Ophthalmic vein / Cavernous sinus
    - **    Inferior Vortex veins —> Inferior Ophthalmic venous plexus / Cavernous sinus
    - Central retinal vein
    - Supraorbital vein
    - Facial vein

Clinical relevance:

  1. Cavernous sinus thrombosis (infection of orbit —> proptosis)
  2. Central retinal vein occlusion (haemorrhage of retina due to blockage of drainage)
39
Q

***Clinical relevance of Blood supply of eyeballs

A
  1. Central retinal artery occlusion
    **Retinal circulation occluded by emboli
    —> Choroidal circulation **    unaffected
    —> **Cherry red spot at fovea (unaffected Choroidal circulation) in middle of **Pale retina (occluded Retinal circulation) (oedematous retina due to ischaemia)
  2. Hyphema
    Damage to iris
    —> much bleeding ∵ highly vascularised
    —> bleeding fills anterior segment of eye
3. Cavernous sinus thrombosis
Severe infection of orbit
—> clogged up Cavernous sinus
—> Thrombosis
—> blood unable to drain
—> ↑ Intraorbital pressure
—> Proptosis
40
Q

***Summary of 4 walls of Orbit

A

Medial wall:

  1. Frontal process of Maxilla
  2. Lacrimal bone
  3. Orbital plate of Ethmoid
  4. Sphenoid body

Lateral wall:

  1. Zygomatic bone (anterior)
  2. Greater wing of Sphenoid (posterior)

Inferior wall:

  1. Maxillary bone (medial)
  2. Zygomatic bone (lateral)
  3. Palatine bone (posterior)

Superior wall:

  1. Frontal bone (anterior)
  2. Lesser wing of Sphenoid (posterior)
41
Q

***Orbital fissure and Optic canal

A

Superior + Inferior orbital fissure
- separated into 3 segments by ***annulus of Zinn

Superior orbital fissure:

  • Superior to annulus of Zinn
    1. Lacrimal nerve (CNV1)
    2. Frontal nerve (CNV1)
    3. CN4
  • Inside annulus of Zinn
    1. Nasociliary nerve (CNV1)
    2. CN3 (superior + inferior branch)
    3. CN6
    4. Optic canal (but NOT in orbital fissure)

Inferior orbital fissure:
1. Inferior Ophthalmic vein

42
Q

Arterial supply of Orbit

A

Internal carotid artery —> Ophthalmic artery —>

  1. Anterior + Posterior Ethmoidal artery
  2. Supratrochlear artery
  3. Supraorbital artery
  4. Lacrimal artery
43
Q

Venous drainage of Orbit

A

Posterior:
- Cavernous sinus + Deep facial vein

Anteromedial:

  • Ophthalmic vein
  • Angular vein

Anterolateral:
- Superficial temporal vein

44
Q

***Innervation of Orbit

A

Vision: CN2

Superior orbit + Upper lids sensation:

  • **CNV1
    1. Nasociliary nerve —> Anterior + Posterior ethmoidal nerve
    2. Frontal nerve —> Supraorbital nerve
    3. Lacrimal nerve

Inferior orbit + Lower lids sensation:

  • **CNV2
    1. Infraorbital nerve
    2. Zygomatic nerve

Motor:

  • Extraocular muscles: CN3, 4, 6
  • Opening of lids: CN3
  • Eye closure + Brow movement: CN7
45
Q

Clinical relevance of Orbit

A

Blow out fracture:
Fracture in ***orbital floor
—> damage in Infraorbital nerve
—> Infraorbital numbness (∵ nerve damage + compression)

46
Q

***Movement of Extraocular muscles

A

Medial rectus: Adduction (向內望)
Lateral rectus: Abduction (向外望)

Superior rectus: Elevation (+ adduction, intorsion)
Inferior rectus: Depression (+ adduction, extorsion)

Superior oblique: Intorsion (向內擰) (+ abduction, depression)
Inferior oblique: Extorsion (向外擰) (+ abduction, elevation)

47
Q

Innervation of Extraocular muscles

A

CN3:

  • Superior rectus
  • Inferior rectus
  • Medial rectus
  • Inferior oblique

CN4:
- Superior oblique (***Contralateral)

CN6:
- Lateral rectus

48
Q

Insertion + Origin of Extraocular muscles

A

Medial rectus:

  • Origin: Annulus of Zin
  • Insertion: 5.3-5.5mm from Corneal limbus (corneal-scleral junction)

Lateral rectus:

  • Origin: Annulus of Zin
  • Insertion: 6.9mm from from CL

Superior rectus:

  • Origin: Annulus of Zin
  • Insertion: 7.7mm from CL

Inferior rectus:

  • Origin: Annulus of Zin
  • Insertion: 6.5mm from CL

Superior oblique:

  • Origin: Annulus of Zin (anatomical), Trochlea (functional)
  • Insertion: 12-14mm behind CL (anterior end), 17-19mm behind CL (posterior end)

Inferior oblique:

  • **Origin: **Maxilla (From a shallow depression on orbital plate of Maxilla)
  • Insertion: Lower + Upper sclera behind equator
49
Q

Suspensory ligament of eyeball

A
  • Suspend eyeball in orbit
  • Connect between EOM
  • Help different EOM in place
  • act as fulcrum (支點) / pulley as EOM move in orbit
50
Q

Higher coordination centres for eye movement

A 
Midbrain + Pons
—> coordinators for eye movement
—> e.g. Activate Lateral + Medial rectus on 2 eyeballs, Inhibit Antagonist of each eyeball
1. Synchronised eye movement
2. Image stabilisation
3. Saccadic eye movement
4. Smooth pursuit eye movement
5. Optokinetic response
6. Other movements

Midbrain / Nerve / Orbital problems that limit the coordination —> Diplopia

51
Q

Eyelid

A
  1. ***Thin fold of skin —> covers and protects eye
    - thinnest skin in whole body
    - fine row of eyelashes —> protect from dust, foreign body, perspiration
  2. Regularly ***spread tears, other secretions —> keep eye moist
  3. ***Corneal + Menace reflex —> protect eye from foreign body
52
Q

Anatomy cross section of Eyelid

A

Above lid crease

  1. Skin
  2. Orbicularis muscle
  3. Orbital septum
  4. Orbital fat (behind orbital septum)
  5. Levator aponeurosis tendon
  6. Superior tarsal muscle (innervated by sympathetic NS)
  7. Conjunctiva

Below lid crease

  1. Skin
  2. Orbicularis muscle
  3. Tarsal plate (maintain shape + secrete oily substance)
  4. Conjunctiva
53
Q

Asian vs Caucasian eyelid

A

Asian:

  • Lower lid crease
  • Smaller tarsal plate
  • Lower orbital fat (眼腫腫)
  • 50% single lid crease

Caucasian:

  • Higher lid crease
  • Larger tarsal plate
  • Orbital fat above lid crease
  • Almost all have double lid crease
54
Q

Blood supply of eyelids

A

Artery:
Superior + Inferior **Palpebral arterial arcades
- Anastomosis between Facial artery + **Medial Palpebral (from Ophthalmic artery) + ***Lateral Palpebral (from Lacrimal artery)

Venous:
Superior + Inferior ***Palpebral vein
—> Angular vein + Facial vein etc.

55
Q

***Supraorbital foramen + Infraorbital foramen

A

Supraorbital foramen / groove:

  • Supraorbital artery (Ophthalmic artery)
  • Supraorbital nerve (CNV1) —> upper lid

Infraorbital foramen:

  • Infraorbital artery (Maxillary artery)
  • Infraorbital nerve (CNV2) —> lower lid
56
Q

***Lacrimal gland + Meibomian glands

A
  1. **Lacrimal gland:
    - in **    Lacrimal fossa of Frontal bone (外側上面)
    - Produce ***tears (together with other smaller palpebral glands)
    - Lubricate eye

Physiology:
Blinking causes tear to travel and distribution of tears over the globe
—> ***Lacrimal sac (內側) pump mechanism while blinking
—> draws tears into it via drainage system

  1. **Meibomian glands at lid margins —> make **Meibom —> prevent tears from evaporating quickly
57
Q

***Tears drainage system

A

Blinking causes tear to travel and distribution of tears over the globe
—> Superior + Inferior **punctum / papilla
—> Superior + Inferior **canaliculus
—> **Common canaliculus
—> Drain / suck into **Lacrimal sac
—> **Nasolacrimal duct
—> **Inferior meatus

58
Q

Clinical relevance of Nasolacrimal duct

A

***Dacrocystitis
Blockage of NLD
—> infection of Lacrimal sac

Treatment:
- Drainage surgery to relieve abscess

Definitive treatment:
- Dacryocystorhinostomy (make a connection to nose)

HNNS (58 decks)

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