OPHTHALMOLOGY: 476-479

Question 1

What type of vision impairments improve with glasses?

Answer 1

Refractive errors

Question 2

What are 4 types of refractive errors?

Answer 2

1. Hyperopia
2. Myopia
3. Astigmatism
4. Presbyopia

Question 3

What is hyperopia?

Answer 3

Eye too short for refractive power of cornea and lens - light ends up being focused behind the retina

Question 4

What is myopia?

Answer 4

Eye too long for refractive power of cornea and lens - light ends up being focused in front of the retina

Question 5

In a patient with astigmatism, why is the refractive power different at different axes?

Answer 5

Abnormal curvature of the cornea

Question 6

Why is there a decrease in focusing ability during accommodation in presbyopia?

Answer 6

Sclerosis and decreased elasticity

Question 7

Name the 2 structures inflamed in uveitis and 2 accompanying symptoms.

Answer 7

2 structures: anterior uvea and iris

2 symptoms: hypopyon (sterile pus) and conjunctival redness

Question 8

What does long term retinitis lead to?

Answer 8

Scarring (from retinal edema and necrosis)

Question 9

Name 3 common causes of retinitis.

Answer 9

Viral - CMV, HSV, HZV

Question 10

What type of patient is more likely to get retinitis?

Answer 10

Immunosuppressed

Question 11

On physical exam, you notice that a patient has a cloudy retina with attenuated vessels and a “cherry-red” spot at the fovea. What is your diagnosis?

Answer 11

Central retinal artery occlusion

Question 12

How does central retinal artery occlusion present?

Answer 12

Acute, painless monocular vision loss

Question 13

What is retinal vein occlusion usually secondary to?

Answer 13

Blockage of the central or branch retinal vein is often secondary to compression from nearby arterial atherosclerosis

Question 14

What 2 things are typically observed in retinal vein occlusion in the affected area?

Answer 14

Retinal hemorrhage and edema

Question 15

What are the 2 types of diabetic retinopathy?

Answer 15

Proliferative and non-proliferative

Question 16

What metabolic imbalance causes diabetic retinopathy?

Answer 16

Chronic hyperglycemia

Question 17

Describe what happens in non-proliferative diabetic retinopathy.

Answer 17

Damaged capillaries leak blood –> lipids and fluid seep into retina –> hemorrhages and macular edema

Question 18

What is the treatment for non-proliferative diabetic retinopathy?

Answer 18

Blood sugar control, macular laser

Question 19

What proliferates in proliferative diabetic retinopathy and why?

Answer 19

New blood vessel formation due to chronic hypoxia. This leads to traction on the retina.

Question 20

What is the treatment for proliferative diabetic retinopathy?

Answer 20

Peripheral retinal photocoagulation, anti-VEGF injections

Question 21

Describe the flow of aqueous humor.

Answer 21

1. Synthesized by the ciliary epithelium on the ciliary muscle
2. Secreted into the posterior chamber
3. Flows between the front of the lens and the back of the iris into the anterior chamber
4. Drains out of the eye via trabecular meshwork into the Canal of Schlemm

Question 22

What is the definition of glaucoma and what are 2 common symptoms?

Answer 22

Optic disk atrophy with characteristic cupping often presenting with:

1. Increased intraocular pressure
2. Progressive peripheral visual field loss

Question 23

What are the two types of glaucoma?

Answer 23

Open angle and closed/narrow angle

Question 24

Is open angle painful?

Answer 24

No - Painless

Question 25

In what kind of patients is open angle glaucoma more common in?

Answer 25

Older, African-American, family history, more common in the U.S.

Question 26

What is the cause of primary open angle glaucoma?

Answer 26

Unclear

Question 27

Name the major problem in secondary open angle glaucoma and 3 potential causes.

Answer 27

Blocked trabecular meshwork from any of the following: 1. WBC's (e.g. uveitis) 2. RBC's (e.g. vitreous hemorrhage) 3. Retinal elements (e.g. retinal detachment)

Question 28

Describe the pathogenesis in primary closed/narrow angle glaucoma.

Answer 28

Enlargement or forward movement of the lens against the central iris leads to obstruction of normal aqueous flow through the pupil --> fluid builds up behind the iris --> peripheral iris pushes against the cornea --> impedes flow through the trabecular meshwork

Question 29

What is the major problem in secondary closed/narrow angle glaucoma?

Answer 29

Hypoxia from retinal disease (e.g. diabetes, vein occlusion) induces vasoproliferation in the iris causing contraction of the angle --> impaired flow

Question 30

Compare and contrast acute vs. chronic closure in closed/narrow angle glaucoma.

Answer 30

Chronic - often asymptomatic with damage to optic nerve and peripheral vision Acute - EMERGENCY, very painful, sudden vision loss, halos around lights, rock-hard eye, frontal headache

Question 31

What drives acute closure in closed angle glaucoma?

Answer 31

Increased intraocular pressure pushes the iris forward and closes the angle abruptly

Question 32

What is contraindicated in acute closure in closed angle glaucoma? Why?

Answer 32

Epinephrine because of its mydriatic effect

Question 33

What is a cataract?

Answer 33

Painless opacification of the lens

Question 34

Are cataracts often unilateral or bilateral?

Answer 34

Bilateral

Question 35

What are some risk factors for cataracts?

Answer 35

``` CATARACTS: Cigarette Age (older) Trauma Alcohol ``` Rare genetic metabolic disorders (classic galactosemia, galactokinase deficiency) Autosomal recessive Corticosteroids Tanning (excessive sunlight) Sorbitol or sugar (diabetes)

Question 36

Is papilledema usually unilateral or bilateral?

Answer 36

Bilateral

Question 37

What is papilledema?

Answer 37

Optic disc swelling due to increased intracranial pressure

Question 38

On fundoscopic exam, what is observed with papilledema?

Answer 38

Enlarged blind spot and elevated optic disc with blurred margins

Question 39

Which cranial nerve innervates the lateral rectus?

Answer 39

CN VI

Question 40

Which cranial nerve innervates the superior oblique?

Answer 40

CN IV

Question 41

What does CN III innervate?

Answer 41

Superior rectus, inferior rectus, medial rectus, inferior oblique

Question 42

Patient's eye looks down and out. Which cranial nerve is damaged and what else do you expect to see?

Answer 42

CN III Also expect ptosis, pupillary dilation, loss of accomodation

Question 43

What happens if you damage CN VI?

Answer 43

Medially directed eye that cannot abduct

Question 44

What three motions does the superior oblique mediate?

Answer 44

Abduction, intorsion, depression

Question 45

If CN IV is damaged, what does the eye do?

Answer 45

Eye moves upward, particularly with contralateral gaze and head tilt toward the side of the lesion

Question 46

Do the obliques move the eye in the same or opposite direction as their name suggests?

Answer 46

Opposite

Question 47

Describe the pathway of light through the eye.

Answer 47

Cornea --> aqueous humor (anterior chamber) --> iris --> pupil --> lens --> vitreous chamber --> retina --> optic nerve

Question 48

Where is vision the sharpest?

Answer 48

At the fovea centralis in the center of the macula

Question 49

Where is the blind spot?

Answer 49

At the optic disc, where the nerve joins the retina

Question 50

What are the three layers of the eye that go all the way around?

Answer 50

Sclera - white of the eye Choroid - vascular layer Retina - contain the receptors for vision

Question 51

What bends the light so it reaches the macula?

Answer 51

Lens

Question 52

What is the purpose of the ciliary body?

Answer 52

Controls the lens

Question 53

Which structure controls the size of the pupil?

Answer 53

Iris