EYE 0426

Question 1

retinitis

Answer 1

retinal necrosis + edema = atrophic scar

Question 2

iritis

Answer 2

systemic inflammation

Question 3

near vision (myopia)

Answer 3

ciliary muscle contracts: zonular fibers relax, lens relaxes, more convex.

Question 4

distant vision (hyperopia)

Answer 4

ciliary muscle relaxes: lens flattens.

Question 5

aging

Answer 5

sclerosis and decreased elasticity causes PRESBYOPIA (no near vision)

Question 6

retinal artery occlusion

Answer 6

acute, PAINLESS monocular vision loss.

pale retina, cherry red macula (choroid artery).

Question 7

glaucoma

Answer 7

increased intraocular pressure due to impaired flow of aqueous humor.

results in optic disk atrophy with cupping.

Question 8

open/wide angle glaucoma

Answer 8

obstructed outflow (canal of Schlemm).
assoc. with myopia, age, Af Am.
more common.
painless and silent.

Question 9

closed/narrow angle glaucoma

Answer 9

obstruction of flow between iris and lens.
pressure builds up behind iris, in posterior chamber.
iris pushed forward against cornea and blocks flow through trabecular meshwork.

very painful.
decreased vision.
rock-hard eye.
frontal headache.
ophtho emergency.
DO NOT GIVE EPINEPHRINE.

Question 10

glaucoma tx: alpha agonist

Answer 10

epinephrine: decrease aq humor synthesis by vasoconstriction. SE: mydriasis, stinging.
brimonidine: decrease aq humor synthesis. no pupillary or vision changes.

Question 11

glaucoma tx: beta blockers

Answer 11

timolol, betaxolol, carteolol.

decrease aq humor secretion.

Question 12

glaucoma tx: diuretics

Answer 12

acetazolamide.

decrease aq humor secretion due to inhibition of carbonic anhydrase, decrease HCO3-.

Question 13

glaucoma tx: cholinomimetics

Answer 13

direct: pilocarpine, carbachol.
indirect: physostigmine, echothiophate.
increase outflow of aq humor.
contract ciliary m. and open trab meshwork into canal of Schlemm.
SE: miosis, cyclospasm.

use PILOCARPINE in emergencies.

Question 14

glaucoma tx: prostaglandin

Answer 14

latanoprost (PGF2a).
increase outflow of aq humor.
SE: darkens color of iris (BROWNING).

Question 15

cataract

Answer 15

painless, bilateral opacification of lens = decrease in vision.

Question 16

cataract RFs

Answer 16

age
smoking
alcohol
sunlight
classic galactosemia
galactokinase deficiency
diabetes (SORBITOL)
trauma
infection
steroids

Question 17

papilledema

Answer 17

increased intraCRANIAL pressure.
elevated optic disk with blurred margins.
bigger blind spot.
ex: HYDROCEPHALUS.

Question 18

CN III damage

Answer 18

eyes looks down and out.

mydriasis, ptosis, loss of accomm.

Question 19

CN IV damage

Answer 19

eye drifts up - vertical diplopia.

trouble going downstairs and reading newspaper.

Question 20

CN VI damage

Answer 20

medially directed eye

Question 21

constriction of pupil (miosis)

Answer 21

pupillary sphincter m. (circular m.)
parasymp.
CN III from e-w nucleus to ciliary ganglion.

Question 22

dilation of pupil (mydriasis)

Answer 22

pupillary dilator m. (radial m.)
symp innervation.
T1 pregang symp to superior cervical ganglion to postsymp symp to long ciliary n.

Question 23

marcus gunn pupil

Answer 23

AFFERENT pupillary defect.
no bilateral constriction when light shone in affected eye.
BUT both eyes constrict when light shone in normal eye.

due to optic nerve damage or retinal detachment.

Question 24

inner CN III

Answer 24

output to ocular mm.
affected by vascular disease (diabetes).
decreased perfusion to inner nerve.

result: lose CN III mm. ptosis. down and out gaze.

Question 25

outer CN III

Answer 25

parasymp output.
affected by compression (uncal herniation, PCOMM berry aneurysm).

result: “blown pupil” (mydriasis - no constriction, always dilated).

use pupillary light reflex to assess.

Question 26

retinal detachment

Answer 26

separation of neurosensory layer of retina from pigment epithelium = degeneration of photoreceptors = vision loss.

may be second to trauma, diabetes.

Question 27

ARMD

Answer 27

degeneration of macula (central area of retina with highest visual acuity).

LOSS OF CENTRAL VISION (SCOTOMA).

presents with difficulty doing ADL (reading, driving).

Question 28

dry, atrophic ARMD

Answer 28

slow, gradual loss in vision.
due to fat deposits.
can progress to WET.

Question 29

wet ARMD

Answer 29

FAST.
due to neovascularization.
increased VEGF.
gray subretinal membrane.

Question 30

visual field defects

Answer 30

remember that temporal visual fields CROSS in optic chiasm to run with nasal visual fields of opposite eye.

Question 31

Meyer’s loop

Answer 31

inferior retina field (SUPERIOR VISUAL FIELD).
loops around inferior horn of lateral ventricle.

injury via temporal lobe, MCA.
upper quadrantic anopia.

Question 32

dorsal optic radiation

Answer 32

superior retina field (INFERIOR VISUAL FIELD).
takes shortest path via internal capsule.

injury via parietal lobe, MCA.
lower quadrantic anopia.

Question 33

visual cortex

Answer 33

macular sparing with all cortical lesions.

injury via PCA.

Question 34

optic nerve injury

Answer 34

unilateral ANOPIA

Question 35

optic chiasm injury

Answer 35

bitemporal hemianopia

Question 36

optic tract injury

Answer 36

homonymous hemianopia

Question 37

internuclear ophthalmoplegia (MLF syndrome)

Answer 37

lesion in medial longitudinal fasciculus = medial rectus palsy on attempted lateral gaze.

normal (abducting) eye = nystagmus.
convergence (CN III) normal.
common in MS.