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First Aid STEP 1 - Neurology > Ophthamology > Flashcards

Flashcards in Ophthamology Deck (40)
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1

What is the definition of hyperopia?

eye too short for refractive power of cornea and lens --> light focused behind retina

2

What is the definition of myopia?

eye too long for refractive power of cornea and lens --> light focused in front of retina

3

What is the definition of astigmatism?

abnormal curvature of cornea resulting in different refractive power at different axes

4

What is the definition of presbyopia?

decrease in focusing ability during accommodation d/t sclerosis and decreased elasticity

5

What is the definition of uveitis?

inflammation of anterior urea and iris, with hypopyon (sterile pus), accompanied by conjunctival redness

6

What diseases are associated with uveitis?

sarcoid, RA, juvenile idiopathic arthritis, TB, HLA- B27 - assoc. conditions

7

What is the definition of retinitis?

retinal edema and necrosis --> scarring

8

What diseases are associated with retinitis?

immunosuppression

often VIRAL (CMV, HSV, HZV)

9

What clinical findings are seen with central retinal artery occlusion?

acute, painless monocular vision loss

retina cloudy with attenuated vessels and "cherry-red" spot at the fovea

10

What is the definition of retinal vein occlusion?

blockage of central or branch retinal vein d/t compression from nearby arterial atherosclerosis --> retinal hemorrhage and edema in affected area

11

What are the 2 types of diabetic retinopathy?

Diabetic retinopathy = retinal damage d/t chronic hyperglycemia

Type 1: non-proliferative - damaged capillaries leak blood --> lipids and fluid seep into retina --> hemorrhages and macular edema. Tx: blood sugar control and macular laser

Type 2: proliferative - chronic hypoxia --> new blood vessel formation with resultant traction on retina Tx: peripheral retinal photocoagulation, anti-VEGF injections

12

What structure of the eye collects aqueous humor that flows through the anterior chamber?

trabecular meshwork

13

What structure in the eye collects aqueous humor from the trabecular meshwork?

Canal of Schlemm

14

What are findings of glaucoma?

characteristic "cupping"
usually with increased intraocular pressure (IOP) and progressive peripheral visual field loss

15

What risk factors are associated with open angle glaucoma?

Increased age
African Americans
family history

16

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

enlargement or forward movement of lens against central iris --> obstruction of normal aqueous flow through pupil --> fluid builds up behind iris --> peripheral iris pushed against cornea, impeding flow through trabecular meshwork

17

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

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

18

Very painful, sudden vision loss, halos around lights, rock-hard eye, and frontal HA are associated with what emergent condition?

acute closed angle glaucoma

19

What are risk factors for cataracts?

old age
smoking
alcohol
excessive sunlight
prolonged corticosteroid use
classic galactosemia
galactokinase deficiency
diabetes (sorbitol)
trauma
infection

20

What is papilledema?

optic disc swelling d/t increased intracranial pressure

21

What physical exam findings will you see with papilledema?

enlarged blind spot
elevated optic disc with blurred margins seen on fundoscopic exam

22

What can be observed with CN III damage?

eyes look DOWN and OUT
ptosis
pupillary dilation
loss of accommodation

23

What can be observed with CN IV damage?

eyes move UPWARD

often have problems going down the stairs, may present with compensatory head tilt in the opposite direction

24

What can be observed with CN VI damage?

medially directed eye that cannot abduct

25

What is the nerve path for miosis?

1st neuron: Edinger-Westphal nucleus to ciliary ganglion via CN III

2nd neuron: short ciliary nerves to pupillary sphincter muscles

26

What is the nerve path for mydriasis?

1st neuron: hypothalamus to ciliospinal center of Budge (C8-T2)

2nd neuron: exit at T1 to superior cervical ganglion (travels along cervical sympathetic chain near lung apex, subclavian vessels)

3rd neuron: plexus along internal carotid, through cavernous sinus; enters orbit as long ciliary nerve to pupillary dilator muscles

27

How does illumination in 1 eye result in bilateral pupillary constriction?

light in either retina sends a signal via CN II to pretectal nuclei in midbrain --> activates bilateral Edinger-Westphal nuclei --> bilateral pupil constriction

28

What is a Marcus Gunn pupil?

afferent pupillary defect where you see decreased bilateral pupillary constriction when light is shone in affected eye relative to unaffected eye.

Caused by damage to OPTIC NERVE or SEVERE RETINAL INJURY

29

With damage to CN III, what physical findings will you see?

a "down and out" gaze

30

What is the pathogenesis of retinal detachment?

separation of neurosensory layer of retina from outermost pigmented epithelium --> degeneration of photoreceptors --> vision loss