Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

COT > Refractometry: Retinoscopy and Refinement 5% > Flashcards

Refractometry: Retinoscopy and Refinement 5% Flashcards

1
Q

Devices that are integrated into each other to automatically input data and to work together to determine the patients refractive error.

A

Automated Refractors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Automated Refraction systems may include:

A

phoropters, lensmeters, autorefractors, keratometers and may be integrated with the electronic records.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Group of ophthalmic devices used to determine refractive error.

A

Automated refraction system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Used as a starting point for subjective testing

A

Auto refractor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some advantages of automated Refraction systems?

A

Lens manual labor
More automation of repetitive tasks in the refraction
ability to present former and new values quickly for validation
Reduced risk of human error due to direct transmission of results EMR
Improved office efficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The amount of light that one candle generates from 1 foot away from a surface.

A

One foot candle of light(1 lumen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The intensity of light which on candle casts on a surface from a distance of one foot

A

One foot candle of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The amount of light cast is inversely related to the distance the candle is from the ______

A

surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The further away you move the light from what you want to illuminate the _____bright the light seems

A

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

If you measure he amount of light intensity right at the light it is ______ but when you measure at the object you have illuminated it is ___light the further away you are from that object

A

just as bright
less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The light that is measure on an object is inversely proportional to the ______the object is from the light source.

A

distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The closer you are to the light bulb the ____ the bulb is.

A

brighter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

You can’t change the amount of light coming from a bulb so in order to make more light on an object you have to move it ____ or ____

A

closer or add more light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Law that describes the relationship between the 2 angles and the index of refraction of the medium through which the light passes

A

Snell’s Law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A measurement of the angle between the incident ray and the normal line

A

angle of incidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A measurement of the angle between the refracted ray and the normal line.

A

angle of refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When light passes from air into water it is bent towards the normal line,__________

A

angle of incidence.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Physics principle that describes optics and the relationship between the angle of incidence and the angles of refraction when referring to light that passes through a boundary between 2 different media, such as water, glass or air. In optics it is used to compute the angles of incidence or angles of refraction and find the refractive index of the given material.

A

Snell’s law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In a glass of water with a straw….
the theoretical line that is placed perpendicular to the interface between the 2 substances air and water. This line is used to measure angles from.

A

Normal line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

With a glass of water with a straw:
The straw as it enters the water is he

A

incidence ray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

With glass of water with straw….
The part of the straw that is in the water is our….

A

Refracted Ray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

With glass of water with straw.:
When light passes air into water the ray of light is refracted or bent. The refracted ray is bent/refracted toward the _______. Our _________ is a measure of angle between the incident ray and the normal line. Our ________ is a measurement of the refracted ray and the normal line. When light passes from air into water it is bent towards the normal line.

A

normal line
angle of incidence
angle of refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

A measure between the angle of the incident ray and the normal line is _____

A

the angle of incidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

A measurement of the refracted ray and the normal line is_____

A

angle of refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

angle of incidence is always______ than your angle of refraction

A

larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Prism fragments the light into

A

the different colors of the spectrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

If you look closely in the refracted ray you will see….

A

the colors of the rainbow in order by wavelength.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What color has the longest wavelength

A

Red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What color has the shortest wavelength

A

violet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the Mnemonic for colors and wavelengths

A

ROYGBIV
start with the longest and end with the shortest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the definition of 1D

A

that lens which brings light to a focal point at a distance of 1M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The higher power the lens the _____it’s focal length

A

shorter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The lower the power of the lens the ____it’s focal length

A

longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

4D lens has a ____focal length and a .25D lens has a ______focal length

A

short
long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the formula to figure out focal length

A

D=1/F
Note : 100cm=1M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Eyes that form a focal point behind the macula

A

Hyperopia (eye is short)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Convex lens pull focal length in ____

A

closer to the macula
converge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Eye that form a focal point in front of the macula

A

myopic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Concave lens pulls focal point _______ so that it falls on the macula

A

further back into the eye
diverge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Rebounding of light is called…

A

reflection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

When light is reflected off of a plane mirror

A

The light is reflected at the same angle you direct it at
angle of incidence = angle of reflection
holding light at 45 degree reflects light at 45 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

A flat mirror

A

plane mirror

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

angle of incidence =

A

angle of reflection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Projectors are put into position so that the light is _______

A

reflected off the mirror and into the pts eye.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Why do we use mirrors to check visual acuity?

A

so we don’t have to have the 20 foot room

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

The angle that the projector is from the mirror must….

A

be the exact same angle at which the pt is from the mirror in order for the pt to view the eye chart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

______mirrors reflect light convergently

A

concave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Mirrors that magnify images(like the round mirror in department store)

A

concave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

____mirror reflect light divergently

A

Convex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Mirrors that minimize images (like the side view mirror on car)

A

Convex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Name the parts of the phoropter.

A

Occluder, sphere power display, sphere power dial, cylinder power knob, axis dial, VD knob, jackson cross cylinder, cylinder power display, level, PD knob

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What should you do first before starting the refraction and retinoscopy?

A

Level the phoropter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Why must we level the phoropter prior to refracting the pt?

A

to make sure we are accurately representing the pts astig axis. If we don’t the axis is inaccurate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

When refracting start with….

A

The AR, Retinoscopy, or WRx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the steps to take before refracting?

A
  1. Start with AR, Retinoscopy, or WRx
  2. Position the phoropter in front of the pt
  3. level the phoropter
  4. Occlude the left eye so the pt is looking with the right eye only
  5. Open the eye chart to one line larger than the line they read with their glasses
  6. Tell pt Look at a letter you can see easily
  7. Encourage pt blinking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Steps of refracting:

A
  1. Sphere(0.50 increments) offer more plus first
  2. Determine axis then cyl with Jackson Cross Cylinder (JCC) (use Dots, Landolt’s Broken ring chart, or one line larger than BCVA on Snellen)
  3. Balance Sphere & Cyl (for each 0.50 change in cyl power, you must adjust the sph power by 0.25 in the opposite direction)
    4.Refine Sphere (0.25 increments) offer more plus first.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

The smallest cross-section of the blur circle between two focal lines formed by an astigmatic lens. (the macula will ideally be in between the 2 focal planes)

A

Circle of least confusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

An eye that has_____forms two focal plans, not 2 focal points ( 2 lines of light rather than to points of light.

A

astigmatism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

The 2 focal planes in an astigmatic eye are typically separated by __degrees and one or both of the planes are not on the macula

A

90

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the goal when refracting an astigmatic eye

A

to get the 2 focal planes as close to each other as possible and as close to the macula as possible. Ideally the macula will be right in between the 2 focal planes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Theoretical point in the eye formed by a spherocylinder lens that represents the area of the least amount of blur

A

circle of least confusion

62
Q

Why do we have to balance our sphere and cylinder

A

without adjusting them you make the focal planes further apart instead of closer together, inducing blur

63
Q

What is the purpose of the +1.00 Blur test?

A

To avoid over minus-ing patient

64
Q

How do you perform +1.00 blur test?

A

1.After monocular refraction is complete
2. ck monocular va
3. Add +1.00 sph (tell pt it will be blurry)
4. Check VA (should be approx 2 lines worse if not, add + sph until it is)
5. Reduce + sph in 0.25D increments
6. ck VA after each click (do not ask “better one or two”)
7. Stop removing +sph as soon as BVA attained

65
Q

When is over minusing an issue?

A

When pt is young or latent hyperope
(usually done if supsected latent hyperope or under age 45)

66
Q

What is the purpose of binocular balancing?

A

to equalize the accommodation efforts of the 2 eyes.

67
Q

You can only perform binocular balancing when pt has….

A

approximately equal visual acuity in each eye

68
Q

A slight imbalance in favor of dominant eye is ..

A

ok

69
Q

Be careful ______to reverse the natural dominance of the 2 eyes.

A

never

70
Q

All methods of binocular balancing are only for refining_____

A

sphere

71
Q

Explain how to perform Binocular Balancing with low plus blur.

A

-Remove occluder so pt is binocular
-ck binocular VA
-Tell pt you’re going to make things look blurry
-Add+1.00D sph over refraction(RF) in both eyes (this fogs and relaxes their accommodation)
-Measure VA again (should be 2 lines worse. If not, add more plus until it is)
-Reduce plus power in 0.25 increments until BVA obtained(do not ask better one or two)

72
Q

Binocular balancing with the DuoChrome exploits the fact that

A

Light of a longer wavelength is refracted more than light of a shorter wavelength. (red being the longest and green has a much shorter wavelength)

73
Q

Red and green filter test for binocular balancing

A

DuoChrome

74
Q

Explain how to perform binocular balancing with DuoChrome.

A

Put the green and red filter over the snellen eye chart
(Test each eye seperately)
Fog the eye with +0.75sph
Gradually remove in 0.25 increments until backgrounds are equally clear
As you remove the 0.25 increments ask which letters are the clearest and sharpest (letters in green or red back ground)
If they say letters on red background are clearer you add more minus
If they say letters on green background are clearer you add more plus
Mnemonic=RAM GAP (Red add minus, Green add plus)

75
Q

In DuoChrome test, if the letters on the green side are the sharpest you add more____

A

plus

76
Q

In DuoChrome test, if letter in Red are the clearest add_____

A

minus

77
Q

In Duochrome test test each eye _____

A

seperately

78
Q

What is the approximate ADD power at age 40-45

A

+1.00

79
Q

What is the approx ADD power for age 45-50

A

+1.50

80
Q

What is the approx ADD power for ages 50-55

A

+1.75

81
Q

What is the approx ADD power for age 55-60

A

+2.00

82
Q

What is the approx ADD power for ages 60-65

A

+2.50

83
Q

What is the approx ADD power for ages 65+

A

+3.00

84
Q

List the age ranges and corresponding ADD power.

A

Age 40-45 +1.00
Age 45-50 +1.50
Age 50-55 +1.75
Age 55-60 +2.00
Age 60-65 +2.50
Age 65+ +3.00

85
Q

Accommodative amplitude _______as we age.

A

decreases

86
Q

Computer ADDS are typically _____ the power of the reading ADD

A

1/2
(ex: if they normally require 2.50D to read at their preferred distance, their computer ADD would be approx +1.25)

87
Q

Most peoples computer monitors are ____

A

25-30” away

88
Q

Refract for computer the same way you do for reading, but___________

A

at the further distance

89
Q

Most peoples axis are ______to one another in the 2 eyes.

A

mirror image

90
Q

Most axis are oriented near or around ___or ____

A

180 ore 90

91
Q

Younger people tend to be at around axis ____and older people tend to be around_____in plus cyl.

A

90
180

92
Q

The higher the ADD power the ______the pt will have to hold the reading card.

A

closer

93
Q

If pt is tall with long arms, he will generally need _____ADD power than someone who is small with shorter arms.

A

less

94
Q

Is the astigmatic clock subjective or objective

A

subjective

95
Q

A subjective test used to determine approx axis of pt astig

A

Astigmatic clock

96
Q

How do you perform Astigmatic Clock.

A

Blur pt to about 20/50
Ask pt which lines are darkest and most distinct
Take the lower number of the line they choose and multiply by 30
This will give you the approx axis of astig

97
Q

When performing astigmatic clock you multiply the ____number by___

A

lower
30

98
Q

A way to estimate a pt refractive error with objective measurements

A

Retinoscopy

99
Q

Is Retinoscopy subjective or object

A

objective

100
Q

Retinoscopy doesn’t require any _______response on the pts part

A

subjective

101
Q

The retinoscope has and _____system, which shines ____lights into the pts eye, which is then _______as a reflex in the pt pupil.

A

Illuminating
Diverging
Reflected back

102
Q

What is the working distance in Retinoscopy?

A

67cm or 26” (+1.50 lens)-average arms
50cm (+2.00 lens)-shorter arms
It is the distance between the pts eye and the retinoscope

103
Q

Why is it important to know the working distance in retinoscopy?

A

Because you must account for it and subtract the +1.50D from the Refraction (or +2.00 for shorter arms)

104
Q

A wet streak uses ____, a dry streak does not

A

Cycloplegia

105
Q

In Retinoscopy have the pt focus on _____

A

Have pt focus on 20’ non accommodative target(Typically the big E)

106
Q

In Retinoscopy you must ____the fellow eye

A

fog

107
Q

In retinoscopy what are some causes of irregular reflexes?

A

KCN
Warped K from ill fit CL
Subluxated lens
K Scar
Lens opacities
Dirty soft CL
Post op Ks

108
Q

Why should you streak in plus when performing retinoscopy?

A

Because it’s easier to recognize with motion

109
Q

When performing retinoscopy we are comparing the _____________

A

Size, shape and movement of the retinoscope’s light with the reflected light from the patient’s pupil

110
Q

What is the light that comes from the retinoscope called?

A

the intercept

111
Q

The retinoscope has a ____system and a _____system

A

viewing
illuminating

112
Q

The illuminating system shines _____rays of light into the pt eye

A

diverging

113
Q

All retinoscopes have 2 basic setting, a ______mirror setting and a ____mirror setting.

A

Plane
Concave

114
Q

For retinoscopy we use the ___mirror setting in order to have parallel light rays entering the eye

A

plane

115
Q

What are the 2 basic types of Retinoscopes?

A

Copeland or Nikon and all others

116
Q

For Copeland and Nikon retinoscopes the sleeve is _____ for the plane mirror affect. For all other types of retinoscopes the sleeve is ____for the plane mirror affect.

A

up
down

117
Q

The primary disadvantage of the Copeland or Nikon retinoscope design is that it is _______, all other scopes use a hallogen light source that makes visualization of the retinoscopic reflex much easier, particularly when doing through _____pupils and _____

A

non hallogen light source
small
media opacities

118
Q

When performing Retinoscopy on the left eye you hold the scope in you ____and turn the dials on phoropter with the ____hand

A

left
right

119
Q

When performing retinoscopy on the right eye you hold the scope in your_____hand and move the dials on phoropter with _____

A

right
left

120
Q

When performing retinoscopy should both eyes be open or should one eye be closed?

A

both open

121
Q

What is the first things that should be done before performing Retinoscopy?

A

Level phoropter

122
Q

What are the basic steps in performing Retinoscopy?

A
  1. Level phoropter
  2. Fog fellow eye with +1.50
  3. Add minus until both meridians are with motion
  4. While sweeping in both meridians, gradually add plus until one meridian is neutral (this is the sphere meridian)
  5. Move to opposite meridian. If it is at neurality, the refraction is spherical. If it’s not at neutrality gradually add plus cyl until this meridian is neutral. (This is your cylinder meridian and your approx axis)
123
Q

What power should you fog the fellow eye with when performing retinscopy?

A

+1.50

124
Q

Retinoscopy;
Add minus until both meridians are _______

A

with motion

125
Q

Retinoscopy:
While sweeping in both meridians, gradually add plus until_____

A

one meridian is neutral

126
Q

Retinoscopy:
The first meridian to become neutral is_____

A

The Sphere

127
Q

Retinoscopy:
The second meridian to become neutral in the opposite meridian of the first is ______

A

The cyl and approx axis

128
Q

How do you confirm neutrality with retinoscopy?

A

move in slightly closer than your working distance and streak both meridians and you should see with motion, move back slightly and you should see against motion

129
Q

Retinoscopy:
Refine axis using visual clues such as ____ and ____ phenomena and ____techniques.

A

Break
Skew
Straddling

130
Q

Retinoscopy:
___________means that the reflected light through the pupil is moving in the same direction as your intercept.

A

With Movement

131
Q

Retinoscopy:
When you see with motion the focal point is _____

A

behind you

132
Q

Retinoscopy:
When you see with movement you add…

A

plus

133
Q

Retinoscopy:
Against movement means that the reflex through the pupil is …..

A

moving in the opposite direction of your intercetp

134
Q

Retinoscopy:
When you see against movement the focal point is ….

A

in front of you

135
Q

Retinoscopy:
When you see against movement you need to add….

A

minus

136
Q

Retinoscopy:
When you approach neutrality the light becomes much___

A

brighter and moves much faster as refractive error becomes less

137
Q

Retinoscopy:
Small refractive errors will have a ______reflex and larger ones will have a _____reflex

A

bright faster
dull slow

138
Q

Retinoscopy:
When the reflex fills the entire pupil the refracted error has been eliminated and your are at the focal point this is ________

A

neutralization

139
Q

Retinoscopy:
Myope-against movement, add____
Hyperope-with movment, add___

A

minus
plus

140
Q

Just before reaching neutrality in retinoscopy you’ll see the_____

A

zone of doubt

141
Q

Retinoscopy:
The point at which you don’t definitely have with motion but you may not be sure you’re at neutrality.

A

Zone of Doubt

142
Q

Retinoscopy:
When you are at Zone of Doubt what should you do?

A

Move in slightly streak both meridians(should see with motion)
Move back slightly streak both meridains (should see against motion)
If you do you’re at neutrality at working distance

143
Q

Retinoscopy;
Explain the “Skew” phenomena?

A

As you sweep watch the relationship between the direction of the movement between the intercept and the reflex. If the intercept is ‘off axis’ the intercept will appear to move in a ‘skewed’ direction compared to the reflex in the pupil

144
Q

Retinoscopy:
Explain Axis “Break” Phenomena.

A

Do not ‘sweep’…‘spiral’ by rotating your intercept
Notice that the intercept and reflex are not aligned
Reflex is less enhanced when break phenomena is present (reflex is clearer when you’re on axis)
If present, this tells you if you’re off axis

145
Q

What is the straddling technique used for?

A

To confirm your axis

146
Q

Explain Axis Straddling in retinoscopy

A

At the end of the retinoscopy, lean slightly toward the pt. The intercept is positioned and compared at 45 degrees on each side of the axis
If your retinoscopy is correct, the width of the reflex 45 degree on each side of the axis will be the same. If not, turn toward the brighter/narrower band until straddle reflexes are equal in width

147
Q

If you see dual reflex in axis straddling you are ____away from the actual axis.

A

further

148
Q

The bright, narrow band seen inf axis straddling is known as the ___

A

guide

149
Q

The guide(narrow light) in axis straddling is _____to the actual axis.

A

closer

150
Q

In Axis Straddling if both lights are equal width this means….

A

you are at the correct axis

COT (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions