Neuro - Anat & Phys (Eye Applications Pt. 1)

Question 1

What is glaucoma, and its characteristic sign? What other 2 signs/symptoms are associated with it?

Answer 1

Optic disc atrophy with characteristic cupping, usually with increased intraocular pressure (IOP) and progressive peripheral visual field loss

Question 2

What are 3 factors associated with open angle Glaucoma?

Answer 2

Associated with (1) Increased age, (2) African-American race, (3) Family history.

Question 3

What kind of pain do patients with open angle glaucoma experience?

Answer 3

Painless

Question 4

What are the types of glaucoma? Which is more common in the U.S.?

Answer 4

(1) Open angle (More common in U.S.) (2) Closed/Narrow angle

Question 5

What is the cause of primary versus secondary open angle glaucoma?

Answer 5

PRIMARY: cause unclear; SECONDARY: blocked trabecular meshwork from WBCs (e.g., uveitis), RBCs (e.g., vitreous hemorrhage), retinal elements (e.g., retinal detachment);

Question 6

What is the pathogenesis of primary closed/narrow angle glaucoma and its effects?

Answer 6

Primary - enlargement or forward movement of lens against central iris (pupil margin) leads to obstruction of normal aqueous flow through pupil –> fluid builds up behind iris, pushing peripheral iris against cornea and impeding flow through trabecular network

Question 7

What is the pathogenesis of secondary closed/narrow angle glaucoma and its effects?

Answer 7

Secondary - hypoxia from retinal disease (e.g., diabetes, vein occlusion) induces vasoproliferation in iris that contracts angle

Question 8

How does chronic closure glaucoma often present? With what 2 kinds of damage is it associated?

Answer 8

Often asymptomatic with damage to optic nerve and peripheral vision

Question 9

Which type of glaucoma is a true ophthalmic emergency?

Answer 9

Acute closure (of closed/narrow angle) - true opthalmic emergency

Question 10

What is the cause and effect associated with acute closure glaucoma?

Answer 10

Increase IOP pushes iris forward –> angle closes abruptly

Question 11

What are 5 signs/symptoms associated with acute closure glaucoma?

Answer 11

(1) Very painful, (2) Sudden vision loss, (3) Halos around lights, (4) Rock-hard eye, (5) Frontal headache.

Question 12

What drug should not be given to patients with acute closure glaucoma, and why?

Answer 12

Do not give epinephrine, because of its mydriatic effect.

Question 13

What is catarct, and how does it present?

Answer 13

Painless, often bilateral, opacification of lens –> decrease in vision

Question 14

What are 10 risk factors associated with cataract?

Answer 14

Risk factors: (1) Increased age, (2) Smoking, (3) EtOH, (4) Excessive sunlight, (5) Prolonged corticosteroid, (6) Classic galactosemia, (7) Galactokinase deficiency, (8) Diabetes (sorbitol), (9) Trauma, (10) Infection.

Question 15

What is papilledema, and what causes it? Is it usually bilateral or unilateral?

Answer 15

Optic disc swelling (usually bilateral) due to increased intracranial pressure (e.g., secondary to mass effect)

Question 16

What is seen on fundoscopic exam of patients with papilledema?

Answer 16

Enlarged blind spot and elevated optic disc with blurred margins seen on fundoscopic exam.

Question 17

Draw the eye and label the following extraocular muscles attached to it: (1) Superior rectus m. (CN III) (2) Superior oblique m. (CN IV) (3) Trochlea (4) Medial rectus m. (CN III) (5) Inferior rectus m. (CN III) (6) Inferior oblique m. (CN III) (7) Lateral rectus m. (CN VI).

Answer 17

See p. 479 in First Aid 2014 for visual in middle of page

Question 18

Which cranial nerves are associated with each of the following extraocular muscles: (1) Superior rectus m. (2) Superior oblique m. (3) Lateral rectus m. (4) Medial rectus m. (5) Inferior rectus m. (6) Inferior oblique m.

Answer 18

(1) CN III (2) CN IV (3) (CN VI (4) CN III (5) CN III (6) CN III; Think: “cn VI innervates the Lateral Rectus, cn IV innervates the Superior Oblique, cn III innervates the Rest. The chemical formula LR6SO4R3.”

Question 19

What are the symptoms seen with CN III damage?

Answer 19

Eye looks down and out; Ptosis, pupillary dilation, loss of accommodation

Question 20

What are the symptoms seen with CN IV damage?

Answer 20

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

Question 21

What are the symptoms seen with CN VI damage?

Answer 21

Medially directed eye that cannot abduct

Question 22

What is a problem that these patients with CN IV may have? What is a way that they compensate for this damage?

Answer 22

Problems going down stairs, may present with compensatory head tilt in opposite direction

Question 23

What 3 actions does the superior oblique have on the eye?

Answer 23

The superior oblique abducts, intorts, and depresses while adducted

Question 24

Draw an image depicting the direction the patient must look in order to test each of the extraocular muscles.

Answer 24

See p. 479 in First Aid 2014 for visual at bottom

Question 25

Where should your patient look if you are trying to test the Inferior Oblique?

Answer 25

IOU: To test Inferior Oblique, have patient look Up

Question 26

In what direction do the oblique muscles (superior and inferior) move the eye in reference to each other?

Answer 26

Obliques move the eye in the Opposite direction