Week 3 Visual Dysfunction

Question 1

how often does someone in the United States become permanently blind

Answer 1

every 7 minutes

Question 2

Definition of blind

Answer 2

central visual acuity of 20/200 or less in the better eye with best correction, or field limited to less than 20 degrees

Question 3

definition of partially sighted or low vision

Answer 3

visual acuity better than 20/200 but less than 20/70 in better eye with best correction

Question 4

how do blind people learn

Answer 4

through tactile or auditory materials

Question 5

how do partially sighted or low vision people learn

Answer 5

enlarged print, optic aids like a magnifying glass or lens

Question 6

decrease vision loss with AIDS

Answer 6

35-75% of AIDS patients have vision loss, can be totally blind. Early diagnosis is good, but vision loss is a late complication of AIDS

Question 7

Anopsia

Answer 7

lack of vision in an eye, due to the interruption of an optic nerve

Question 8

what is cortical visual impairment

Answer 8

cortical blindness, which is damage to the visual cortex.

Question 9

does the eye show pathology in cortical blindness? what is the physiology

Answer 9

no, it is neurologic damage. The signal isn’t reaching the brain, or there is a hindered organization or decoding of information when it reaches the brain

Question 10

TF: you may be able to get some degree of functional vision if vision stimulation is provided in cortical blindness

Answer 10

true

Question 11

what is diabetic retinopathy

Answer 11

proliferation of blood vessels may cause hemorrhaging into the vitreous or scar formation of the retina.

Question 12

when do vision problems start to occur in people with diabetes

Answer 12

20 years after the onset of the diabetes

Question 13

can vision problems worsen if diabetes is uncontrolled

Answer 13

yes

Question 14

what does diabetic retinopathy look like (if you were the patient)

Answer 14

black spots showing up in the visual fields or areas.

Question 15

what is glaucoma, caused by what

Answer 15

increased pressure in the eye, from faulty drainage of the eye

Question 16

what happens if pressure in the eye continues

Answer 16

decreased blood supply so the peripheral retinal cells die, and the optic nerve may be damaged.

Question 17

what are symptoms of glaucoma

Answer 17

• poor night vision
• halos around lights
• fear of light/ sensitivity (photophobia)
• loss of contrast
• kids: tearing, sensitivity and spasming eye lids

Question 18

what will the patient see if they have glaucoma

Answer 18

peripheral vision is lost, and a dark ring around their field of vision

Question 19

what is hemianopia

Answer 19

interruption of the optic tract, resulting in loss of vision on one side of the visual field, in both eyes. so… images from only 1/2 of each eye will reach the brain. Only receives half-fields for each eye

Question 20

when do we see hemianopia

Answer 20

in CVA/stroke

Question 21

is there a treatment for hemianopia? what can we do

Answer 21

no treatment, we want to alleviate the cause (tumor or bleeding)

Question 22

can we improve visual field loses in hemianopia

Answer 22

maybe with prisms

Question 23

what is the most common hemianopia

Answer 23

right homonymous hemianopia (occurs in corresponding halves of the right visual field

Question 24

what other kinds of hemianopia are there

Answer 24

left homonymous hemianopia (left visual fields)
superior hemianopia (upper field)
inferior hemianopia (lower field)
outer halves of the fields (bitemporal hemianopsia)

Question 25

what happens to vision with brain stem strokes

Answer 25

``` ocular motility issues diplopia oscillopsia visual distortions paralysis of conjugate gaze ```

Question 26

what two things must we differentiate with vision after a stroke

Answer 26

homonymous hemianopsia | neglect

Question 27

is neglect a visual or perception problem

Answer 27

perception

Question 28

can we treat both visual problems and neglect with scanning compensation

Answer 28

no, because you are not aware you have the neglect

Question 29

nystagmus

Answer 29

oscillation of the eyes, movements that are jerky or slow, and decreased acuity because they cannot maintain a steady fixation

Question 30

what happens with a farsighted (hyperopic) eye. symptoms?

Answer 30

the eyeball is too small, and light rays focus behind the fovea of the retina. may not want to read, may rub eyes, HA, dizzy, nausea.

Question 31

what happens with a nearsighted (myopic eye). Symptoms?

Answer 31

eyeball is too long, and light rays focus before they reach the fovea. So you squint and frown.

Question 32

What is astigmatism

Answer 32

irregular curvature of the cornea, causes visual fatigue, HA, frowning and squinting.

Question 33

what is presbyopia

Answer 33

when the lens is less flexible and less able to accommodate for near point viewing. Middle age this happens

Question 34

TF: refractive errors tend to be inherited?

Answer 34

true

Question 35

what are some variables of the eye that can cause refractive errors

Answer 35

size, shape of cornea, shape of lens

Question 36

what are the treatments of refractive errors in the absence of disease

Answer 36

glasses, contacts, lasik

Question 37

can eye exercises help refractive errors

Answer 37

no

Question 38

what is retinitis pigmentosa

Answer 38

hereditary, progressive retinal deterioration, and a slow progressive field loss

Question 39

what does retinitis pigmentosa affect first, rods or cones? what can this lead to

Answer 39

rods, causes night blindness

Question 40

what can retinitis pigmentosa lead to (vision wise)

Answer 40

tunnel vision

Question 41

what is retinopathy of prematurity (ROP)

Answer 41

retrolental fibroplasia (RFL). occurs in premies that get high or prolonged oxygen. it is the proliferation of blood vessels and fibrous tissue through the retina and vitreous, stretches the retina, and can cause a retinal detachment. can have scattered vision

Question 42

what is strabismus. when can it occur

Answer 42

deviation in position of one or both eyes due to muscle imbalance. can at certain distances or time

Question 43

what is amblyopia

Answer 43

lazy eye, (a characteristic of strabismus)

Question 44

TF: strabismus can be corrected with surgery, visual training (patching or eye exercises) or injecting paralyzing drugs into the muscles involved.

Answer 44

true

Question 45

what are the three types of strabismus and which is the most common, least common

Answer 45

estropia (most common) extropia hypertropia (least)

Question 46

estropia

Answer 46

deviation of the eye towards the nose.

Question 47

extropia

Answer 47

deviation of one eye outward

Question 48

hypertropia

Answer 48

deviation of one eye upwards, and is the least common