Head & Neck Surgery: Eyes (Exam II)

Question 1

Eye Anatomy placeholder

Answer 1

Question 2

What produces the aqueous humor?

Answer 2

Ciliary body

Question 3

What artery perfuses the majority of the orbital structures?
Where does this artery branch off from?

Answer 3

Opthalmic artery (branches off the internal carotid).

Question 4

Where does the opthalmic vein drain?

Answer 4

Cavernous sinus

Question 5

Which CN transmits neural signals from the retina?

Answer 5

Optic Nerve (CN II)

Question 6

Which cranial nerves control extraocular muscle movement?

Answer 6

• III (Oculomotor)
• IV (Trochlear)
• VI (Abducens)

Question 7

Which CN transmits pain and touch sensations of the eye?

Answer 7

Trigeminal (V)

Question 8

Which CN innervates the orbicularis muscle via its zygomatic branch?

Answer 8

VII (Facial)

Question 9

Blockade of the facial nerve would prevent what?

Answer 9

Accurate TOF assessment of the orbicularis oculi

Question 10

What provides sensation to the upper and lower eyelids?

Answer 10

• Upper - frontal branch of ophthalmic nerve
• Lower - maxillary nerve

Question 11

What is normal intraocular pressure?

Answer 11

10 - 20 mmHg

Question 12

> ____ mmHg is a pathological intraocular pressure.

Answer 12

> 25 mmHg

Question 13

Quantity of _____ fluid and ______ blood volume help regular IOP.

Answer 13

aqueous fluid : choroidal blood volume

Question 14

Which two anesthesia “things” have the greatest effect on IOP?

Answer 14

• Laryngoscopy
• Emergence

Question 15

Coughing, straining, and vomiting can result in a _______ mmHg increase in IOP.

Answer 15

30 - 40 mmHg

Question 16

How will CO₂ affect IOP?

Answer 16

Hypercapnia = ↑IOP via choroidal congestion

Question 17

Hypoxia and hypertension will ↓IOP. T/F?

Answer 17

True

Question 18

What common anesthetic drugs are known intraocular pressure increasing drugs?

Answer 18

• Succinylcholine
• Neostigmine
• Atropine

Question 19

How much does IOP increase with sugammadex?

Answer 19

Trick question. Sugammadex does not increase IOP.

Question 20

Ocular blocks will increase IOP by 5 - 10 mmHg. Which block will cause the greatest increase?

Answer 20

Peribulbar blocks

Question 21

A forceful squeeze of our eyelids can increase IOP by _____ mmHg.

Answer 21

> 70 mmHg!

Normal blink is 10 mmHg.

Question 22

What common anesthetic drugs decrease IOP?

Answer 22

• VAA
• IV anesthetics
• Short-acting opioids
• Mannitol

Depression of CNS ocular centers = relaxation of extraocular tone.

Question 23

What effect do midazolam, nitrous oxide, and non-depolarizing neuromuscular blockers have on IOP?

Answer 23

No change

Question 24

What is another name for the oculocardiac reflex?

Answer 24

Trigeminovagal Reflex

Question 25

What are the triggers for the oculocardiac reflex?

Answer 25

- Traction on the extraocular muscles. **Especially the medial rectus**. - Pressure on the globe - Retrobulbar block

Question 26

What surgery is the oculocardiac reflex seen in most frequently?

Answer 26

Strabismus repair of pediatric patients.

Question 27

What are non-pharmacologic treatments of the oculocardiac reflex?

Answer 27

- STOP surgery - Correct hypercapnia and/or hypoxia - Prevention/pretreatment

Question 28

What are the pharmacologic treatments for oculocardiac reflex?

Answer 28

- Atropine 7-10 mcg/kg IV - Glycopyrrolate 0.2 mg IV - LA in the rectus muscle

Question 29

Open Angle Glaucoma is a ______ condition.

Answer 29

chronic

Question 30

_____ _____ _____ causes chronic pressure elevation and development of open angle glaucoma.

Answer 30

Trabecular meshwork sclerosis

Question 31

How painful is the development of open angle glaucoma?

Answer 31

Gradual and painless

Question 32

What are the treatment goals of open angle glaucoma?

Answer 32

- ↓ IOP - ↓ aqueous humor production - Trabeculectomy/trabeculoplasty

Question 33

Acute dilation of the iris with obstruction of aqueous drainage is...

Answer 33

Closed angle glaucoma *Very painful*.

Question 34

What is the treatment for closed angle glaucoma?

Answer 34

Iridotomy

Question 35

How quickly must iridotomy be performed for closed angle glaucoma?

Answer 35

< 24 hours

Question 36

_______ drugs **MUST** be avoided in closed angle glaucoma patients.

Answer 36

**Anticholinergic** Drugs - Scopolamine - Antihistamines - Decongestants - Antidepressants - Benzodiazepines - Ipatropium bromide

Question 37

What carbonic anhydrase inhibitor is used for the treatment of chronic glaucoma?

Answer 37

Acetazolamide

Question 38

What two common side effects are seen from acetazolamide?

Answer 38

- Hypokalemia - PONV

Question 39

What type of drug is Echothiophate? What condition does it treat & how?

Answer 39

- Anticholinesterase inhibitor - Treats glaucoma by maintaining miosis

Question 40

Excess echothiophate can result in what?

Answer 40

- Systemic plasma cholinesterase inhibition *Caution with succinylcholine and ester LA's*

Question 41

Phenylephrine using topically on the eye does what?

Answer 41

Dilates the eye *2.5% vs 10%*

Question 42

What drugs are used intraoperatively after lens extraction to induce pupillary constriction?

Answer 42

- Pilocarpine - Acetylcholine

Question 43

What is timolol used for?

Answer 43

Glaucoma via ↓ aqueous humor production *non-selective β1 blocker*.

Question 44

What possible side effects does timolol have?

Answer 44

- ↓ HR - Bronchospasm - CHF exacerbation

Question 45

What type of drug is netarsudil?

Answer 45

Rho Kinase inhibitor *Treats glaucoma*.

Question 46

What is a cataract?

Answer 46

Opacity of the lens of the eye

Question 47

What type of anesthesia is used for cataracts?

Answer 47

- Topical - Regional - Minimal/No IV anesthesia

Question 48

What procedure is defined by the replacement of an infected/traumatized or poorly optical cornea?

Answer 48

Keratoplasty

Question 49

How is a low and stable IOP maintained with a keratoplasty?

Answer 49

Mannitol (used because of lasting effects, 5-6 hours)

Question 50

Is topical anesthesia an option for keratoplasty?

Answer 50

No. - GETA typically

Question 51

What are the advantages to regional anesthesia for keratoplasty's?

Answer 51

- Perioperative analgesia - Akinesia - No oculocardiac reflex - ↓ PONV

Question 52

Answer 52

Succinylcholine *Echothiophate causes plasma cholinesterase inhibition.*

Question 53

What is a trabeculectomy performed for?

Answer 53

Refractory glaucoma *Excision of trabecula to increase drainage of aqueous humor & ↓IOP*.

Question 54

What two drugs are used in a trabeculectomy to prevent flap scarring and increase surgical success?

Answer 54

- Mitomycin-C - 5-FU

Question 55

What is surfer's eye?

Answer 55

Ptyergium = triangular piece of fibrovascular tissue

Question 56

________ is used to prevent recurrence after ptyergium excision.

Answer 56

Mitomycin-C

Question 57

What is Ectropion?

Answer 57

Question 58

What is Entropion?

Answer 58

Eyelid turning inward

Question 59

What is blepharoplasty?

Answer 59

Correction of defect, deformity, or disfiguration of eyelids

Question 60

What is ptosis?

Answer 60

Drooping upper eyelid

Question 61

What is strabismus?

Answer 61

Misalignment of visual axis - Double vision (Diplopia)

Question 62

What conditions is strabismus associated with?

Answer 62

- Trisomy 21 - Cerebral Palsy - Hydrocephalus - Malignant Hyperthermia - Myotonic Dystrophy

Question 63

Describe the postoperative pain and nausea/vomiting after strabismus repair.

Answer 63

- No severe post-operative pain - **PONV** is significant (50 - 80%)

Question 64

What pain control strategies are used for strabismus repair?

Answer 64

- Ketorolac (minimize opioids)

Question 65

What drug is added to local anesthetic injectate to prevent damage to the extraocular muscles?

Answer 65

hyaluronidase

Question 66

What block provides akinesia of the CN II, III, and VI and a sensory block of the conjunctiva and cornea?

Answer 66

Retrobulbar block

Question 67

What are possible complications of retrobulbar block?

Answer 67

- Hematoma - Optic nerve injury - Globe perforation

Question 68

Which cranial nerves are blocked with a peribulbar block?

Answer 68

- CN III & CN VI - CN II **is not blocked**.

Question 69

What complication is avoided with a peribulbar block vs a retrobulbar block?

Answer 69

Retrobulbar hemorrhage

Question 70

What topical anesthetic is used for eye surgeries?

Answer 70

0.5% proparacaine

Question 71

What is blocked (and not blocked) with topical proparacaine?

Answer 71

Blocked: - Conjunctive, cornea, and sclera Not Blocked: - Iris & ciliary body