Vision

Question 1

What makes up the outer layer of the globe?

Answer 1

• sclera
• Limbus
• Cornea

Question 2

What makes up the middle layer of the globe?

Answer 2

• choroid, ciliary body, iris stroma

- melanocytes

Question 3

What makes up the inner layer of the globe?

Answer 3

• retinal pigmented epithelium
• Neural retina
• Ora serrata
• anterior ciliary processes
• posterior iris

Question 4

What is an open globe injury?

Answer 4

-a full thickness laceration or perforation of the cornea, limbus, or cornea

**opthalmic emergency

Question 5

What are the three smooth muscles in the eye?

Answer 5

• constrictor muscle
• Dilator muscle
• circumferential muscle (in ciliary body)

Question 6

What is the Near Synkinesis reflex made up of?

Answer 6

• Accomodation
• Convergence
• Miosis

Question 7

Which nerve controls the levator palbebrae superioris?

Answer 7

CNIII

Question 8

Which nerve controls the circumferential ciliary body muscle?

Answer 8

-CNIII

Question 9

Which nerve controls the Iris constrictor muscle?

Answer 9

CNIII

Question 10

In which portion of the eye is ocular melanoma most common?

Answer 10

-Choroid

Question 11

What types of neurons are in the retina?

Answer 11

• photoreceptors
• bipolar cells
• ganglion cells
• interneurons (horizontal & amacrine cells)

Question 12

What is the blood supply to the retina?

Answer 12

• inner 2/3 = central retinal artery

- outer 1/3 = choroidal vasculature

Question 13

What is the ora serrata?

Answer 13

serrated junction between the retina and the ciliary body

Question 14

What are the signs that can lead to a diagnosis of an open globe injury?

Answer 14

• seidel positive testing
• peaked pupil
• low intraocular pressure

Question 15

What is Nystagmus?

Answer 15

• when eye shakes back and forth very quickly

- common in albinism

Question 16

What are the interneurons of the retina?

Answer 16

• horizontal cells

- amacrine cells

Question 17

What suspends the lens to the ciliary body?

Answer 17

Zonules

Question 18

What collagen is most prominent in the lens?

Answer 18

Type IV collagen

Question 19

What is a cataract?

Answer 19

a crystalline lens that has lost its transparency

Question 20

What are the 5 layers of the cornea?

Answer 20

• stratified squamous epithelium
• Bowman’s layer (Type I)
• Stroma (Type I)
• Descemet’s layer (Type IV)
• Endothelium

Question 21

What is Keratoconus? Which layer causes it?

Answer 21

a degenerative disaease of the cornea that leads to protrusion of the cornea into a cone shape

-bowman’e layer loses integrity

Question 22

What is Fuchs Dystrophy?

Answer 22

• progressive corneal dystrophy involving loss of endothelial cells
• common in older women

Question 23

What drains through the angle of the eye?

Answer 23

Aqueous humor

Question 24

Where is aqueous humor synthesized?

Answer 24

two layers of epithelial cells on the ciliary proccesses

Question 25

Describe the inflow of Aqueous humor.

Answer 25

Ciliary processes > posterior chamber > through pupil > anterior chamber

Question 26

What is the difference between Trabecular outflow and uveoscleral outflow?

Answer 26

Trabecular: Pressure dependent. Trabecular meshwork > Schlemm's Canal > Venous system Uveoscleral: Pressure independent. Anterior Chamber > Ciliary muscle > subraciliary/suprachoroidal spaces > exit via intact sclera or along its nerves/vessels

Question 27

What is the laminar portion of the optic nerve?

Answer 27

- thought to be damaged in glaucoma - continuous with sclera - provides main support for the optic nerve as it exits the eye

Question 28

What is primary open-angle glaucoma?

Answer 28

- trabecular meshwork can become dysfunctional leading to increased outflow resistance - can cause death of CNII fibers **pts experience painless, slow, progressive loss of vision, starting in periphery

Question 29

What are the 5 ways to lower the intraocular pressure?

Answer 29

- modify ANS to slow down blood flow in ciliary body - Induce parasympathetic miosis and accomodation to open up trabecular meshwork - Show down production of aqueous - Mechanically open trabecular meshwork to increase fluid drainage - Create artificial conduit to drain directly into venous system

Question 30

What adrenergic receptors are on the ciliary body, and how do they influence aqueous humor production when activated?

Answer 30

B1/2 = increase production a1/2 = decrease production

Question 31

Which of these drugs is NOT useful in treating glaucoma? 1. Beta 1 blocker 2. Carbonic anhydrase inhibitor 3. Cholinergic agonist 4. Alpha 2 antagonist 5. Acetylcholine esterase inhibitor 6. Marijuana

Answer 31

4. Alpha 2 antagonist

Question 32

Which of the following drugs will dilate pupil and also prevent accommodation? 1. Tyramine 2. Echothiophate 3. Curare 4. Atropine 5. Muscarine

Answer 32

4. Atropine

Question 33

What is the innervation tot he dilator muscle of the eye?

Answer 33

-Sympathetics from the tcarotid plexus (synapsed at superior cervical ganglion)

Question 34

What is the innervation of the constructor muscle of the eye?

Answer 34

-parasympathetics from CNIII

Question 35

Describe accomodation.

Answer 35

- lens is fatter - constriction of the circumferential muscle in the ciliary body - zonular fibers are relaxed

Question 36

What is presbyopia

Answer 36

- patients need reading glasses - normal part of aging - lens loses elasticity, so even though ciliary body contracts, the lens does not get fatter (no accomodation)

Question 37

What nerve controls the near synkinesis reflex?

Answer 37

-CN III

Question 38

Between what two layers does a retinal tear occur?

Answer 38

-Peeling of the photoreceptors from the RPE

Question 39

What is a colorful sign of the congenital form of horner's syndrome?

Answer 39

- Heterochromia | * melanocytes from neural crest

Question 40

Why does the lens continue to thicken as we age?

Answer 40

- lens epithelial cells on the anterior of the lens continuously make basement membrane which migrates posteriorly * anterior capsule continues to thicken while posterior capsule remains 4 um thick

Question 41

What is luekocoria?

Answer 41

-white pupil that is a result of cataracts

Question 42

What is the function of the endotheium of the cornea?

Answer 42

- secrete a basement membrane (Descemet's layer) | - house ATP H2O pumps that remove water out of the stromal matrix to preserve structure & Clarity