Exam 2 (Eyes)

Question 1

What structures make up the Uveal tract?

Answer 1

Choroid, Iris, & Ciliary body

Question 2

What is the purpose of the Choroid?

Answer 2

provides blood flow to the retina

Question 3

What is the purpose of the Ciliary body?

Answer 3

Produces aqueous humor

Question 4

What fills the center of the eye?

Answer 4

Vitreous gel

Question 5

Sympathetic fibers of the Iris originate from?

Answer 5

The carotid plexus

Question 6

Parasympathetic fibers of the Iris originate from the _____.

Answer 6

oculomotor nerve

Question 7

Majority of the orbital structures receive blood supply from the _____ artery, a branch of the _____ and the ____ vein drains directly into the ______

Answer 7

Opthalmic artery
internal carotid
opthalmic vein
cavenous sinus

Question 8

What transmits neural signals from the retina?

Answer 8

Optic (II) nerve

Question 9

What nerves control extraocular muscle movement?

Answer 9

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

Question 10

What nerve senses pain & touch for the eye?

Answer 10

Trigeminal (V)

Question 11

Upper eyelid sensation is innervated by the?

Answer 11

Frontal branch of the ophthalmic nerve

Question 12

Lower eye sensation is innervated by the?

Answer 12

Maxillary nerve

Question 13

What is the normal IOP?

Answer 13

10 - 20 mmHg

Question 14

What regulates IOP?

Answer 14

Resistance at the trabecular meshwork

Question 15

What causes chronic pressure elevation in open-angle glaucoma?

Answer 15

Sclerosis of the trabecular meshwork

Question 16

What causes the most significant increases in IOP?

Answer 16

Intubation & emergence

Question 17

Coughing, straining, & vomiting cause an IOP increase of about?

Answer 17

30 - 40 mmHg

Question 18

What states causes increased IOP?

Answer 18

Hypercapnia
Hypoxia
Hypertension

Question 19

How does hypercapnia increase IOP?

Answer 19

It causes choroidal congestion

Question 20

Scc increases IOP by ____ mmHg

Answer 20

8 - 10 mmHg

Question 21

What block cause the greatest increase in IOP?

Answer 21

Peribulbar block, likely due to volume injected

Question 22

What anesthesia drugs cause increased IOP?

Answer 22

Neostigmine, atropine, Sux

Question 23

A normal blink icreases IOP by ___ mmHg & a forceful lid squeeze by ___ mmHg?

Answer 23

10 mmHg
70 mmHg

Question 24

What drugs decrease IOP?

Answer 24

Volatile & IV anesthetics via relaxation of extraocular muscles
Short-acting opioids
Acetazolamide
Echothiophate (Phospholine Iodide)
Timolol (Timpoptic)

Question 25

What drugs have no effect on IOP?

Answer 25

Midazolam Nitrous oxide NMDAs Suggamadex

Question 26

What triggers the Trigeminovagal reflex?

Answer 26

- Traction on the extraocular muscles (the Medial rectus muscle). - The afferent limb of the reflex limb arises from the ophthalmic division of the trigeminal nerve and travels to the Gasserian ganglion and the sensory nucleus of the trigeminal nerve near the fourth ventricle. The afferent limb synapses with the motor nucleus of the vagus nerve

Question 27

What ventilation states worsen the oculocardiac reflex?

Answer 27

Hypercapnia & hypoxia

Question 28

What condition is characterized by peripheral visual field loss?

Answer 28

Open-angle glaucoma

Question 29

How does open-angle glaucoma lead to increased IOP?

Answer 29

Increased aqueous humor production and/or decreased outflow

Question 30

What causes closed-angle glaucoma?

Answer 30

Acute dilation of the Iris --> blocking drainage of fluid

Question 31

What is the treatment of closed-angle glaucoma?

Answer 31

Iridotomy

Question 32

What drugs are not given in closed-angle glaucoma?

Answer 32

Scopolamine Antihistamines & decongestants Benzos (relax sphincter muscle) Cocaine, Ecstasy, & marijuana Ipratropium bromide (Atrovent) Atropine Nortriptyline (lots of -mines & pines)

Question 33

What is the treatment of the Oculocardiac reflex?

Answer 33

Prevention Stop surgery Give atropine 7 - 10mcg/kg IVP Robinul 0.2mg IVP

Question 34

Which nerves are blocked with a peribulbar block?

Answer 34

CN III (Oculomotor) & CN VI (Abducens)

Question 35

When and why is a peribulbar block performed?

Answer 35

- 20mins before Sx - It is less painful and less increase in IOP

Question 36

Which nerves are blocked with a retrobulbar block?

Answer 36

CN II (Optic) CN III (Oculomotor) CN VI (Abducens)