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NCLE Prep > Janet Approved > Flashcards

Janet Approved Flashcards

1
Q

Simple Hyperopic Astigmatism

A

After minus or plus transposition: Plano +

Parallel rays of light
come to two line foci,
one falling on the retina
and the other falling
behind the retina

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2
Q

Simple Myopic Astigmatism

A

After minus or plus transposition: Plano -

Parallel rays of light
come to two line foci,
one falling on the
retina and the other
falling in front of the
retina

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3
Q

Compound Hyperopic Astigmatism

A

After minus or plus transposition: + +
Both parallel light rays fall
behind the retina
* Both major meridian powers
indicate hyperopia

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4
Q

Compound Myopic Astigmatism

A

After minus or plus transposition: - -

Both parallel light rays come
to two line foci in front of
retina
* Both major meridian powers
indicate the refraction is
myopic

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5
Q

Mixed astigmatism

A

After minus or plus transposition: + -

Parallel light rays come to two-line foci,
one falling in front of the retina and the
other falling behind the retina
* One major meridian indicates the
refraction is hyperopic and the other
meridian indicates the refraction is
myopic

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6
Q

Dk/L

A

refers to the amount of oxygen which pass
through a lens material of specified thickness

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7
Q

Myoflange design

A

an increase in edge thickness to aid in better centering lenses that position low on the cornea.
Extra edge thickness creates greater lid interaction.

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8
Q

Hyperflange design

A

a decrease in edge thickness is indicated in many high minus power lens designs to limit
lid interaction, allowing the lens to position more centrally
on the cornea.

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9
Q

Vertex Distance

A

the distance between the back vertex of
the correcting lens, and the front surface of the eye

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10
Q

Wetting angle

A

the spreadability of water over a lens
surface. The lower the angle, the more wettable the
surface.

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11
Q

Lescometer

A

An attachment that holds
the calibration balls for
the keratometer

Also contains a lens
holder which enables the
keratometer to be used
to measure the base
curve of a rigid contact
lens

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12
Q

when you can’t locate the kertometric mires

A

The instrument and/or patients is not aligned properly

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13
Q

Keratometer has transient mire clarity

A

ask the patient to blink and measure quickly

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14
Q

Transient mire focus in keratometer

A

ensure patient’s forehead is against the headrest

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15
Q

Unstable patient gaze in keratometer

A

close the other eye

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16
Q

H and v mires cannot be measured concurrently in keratometer

A

irregular astigmatism

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17
Q

Only 1 minus sign is visible in the keratometer

A

patient’s eyelid is drooping

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18
Q

Only 1 plus sign is visible in the keratometer

A

occluder is in the way

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19
Q

The modulus of a lens material is the measurement of the
material’s resistance to deformation under tension. In
practical terms, the ____ the lens material, the _____ the
lens modulus

A

stiffer
higher

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20
Q

Visibility tint

A

blue or light green

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21
Q

Spin casting

A

this process, the liquid polymer mix is introduced into a spinning, open top, concave mold that will determine the
front surface configuration of the lens.
The back surface of the lens is formed in air.

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22
Q

Lathe Cutting

A
  • have exhibited the greatest consistency from lens to lens,
    based on the ability to very closely control surface
    curvatures.
  • In this process the polymerized plastic, in a dehydrated,
    rigid state, is formed into lens blanks, mounted in a base
    curve lathe, and the posterior curves
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23
Q

Cast Molding

A
  • In overcoming the previous inconsistency and quality
    disadvantages. The result has been the increasing
    availability of improved quality products at lower costs.
  • Hydrogel lenses produced in a molding process may be
    formed in the rigid, dehydrated state, resulting in a finished
    product that will subsequently be immersed in saline and
    hydrated to the specified degree
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24
Q

3-point touch

A

for soft lenses

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25
Q

Who much astigmatism induced by back surface toric

A

40%

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26
Q

WIth LARS each minute is….

A

6 degrees

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27
Q

With LARS 5 minutes is…

A

30 degrees

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28
Q

purposes for cleaning the lens

A

Clean the lens that is exposed to sebaceous secretions
* Clear the collected protein and debris
* Lower the bacterial count before the disinfection process

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29
Q

Protein removers

A

Enzymatic cleaner
pancreatin enzyme
subtilisin and subtilisin-a
Papin

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30
Q

Surfactant cleaners

A

without use of surfactant cleaner- inadequate disinfection can occur
reduces build-up
used immediately after lens removal

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31
Q

Solution sensitivities and incompatibilities

A

Sensitives normally come from preservatives: BAK, Chlorhexidine, Chlorobutanol, polyquad, dymed, PHMB, potassium sorbate

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32
Q

chemical disinfection

A

marked multi-purpose solutions and no-rub
contain cleaner, disinfectant, enzyme cleaner, and lubricant

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33
Q

Hydrogen peroxide

A

Use highly purified 3% hydrogen peroxide
perservative free
cannot be placed directly in eye

34
Q

Three borate buffers in this system produce a trace
amount of hydrogen peroxide that protects the solution from pathogens while remaining
non-toxic to the patient. The buffering agents keep the pH level stable

A

Antimicrobial Buffer System (ABS)

35
Q

It has wide antifungal and antibacterial effectiveness. a
tendency to bind corneal protein, which may produce superficial punctate keratitis in soft lens
patients.

A

benzalkonium chloride (bak)

36
Q

chlorhexidine

A

this preservative has limited effectiveness against yeast and fungus
organisms, it is often mixed with other solutions for increased strength. Can cause binding of
proteins that could cause corneal sensitivity.

37
Q

chlorobutanol

A

This preservative reacts slowly in killing bacteria and fungus. It is only used in
conjunction with other preservatives like benzalkonium chloride.

38
Q

polyquad, dymed and phmb

A

low concentration preservatives, and are used as disinfecting
agents in multi-purpose solutions.

39
Q

This preservative was first used as a replacement for thimerosal It also
has a tendency to bind to organic deposits on the lens surface and can cause discoloration of
certain contact lens materials.

A

Potassium Sorbate

40
Q

Used primarily as a substitute for thimerosal in soft lens solutions, this
preservative has limited antimicrobial effect on the yeast and fungus groups.

A

sorbic acid

41
Q

thimerosal

A

Many patients have shown adverse sensitivity to solutions containing thimerosal.
Thimerosal and another mercurial, phenylmercuric nitrate, are not as effective against gram
negative organisms as some other preservatives. Thimerosal is rarely used in care systems in
the United States.

42
Q

… Instructions must be provided on insertion, removal,
re-centering, solutions, storage, wearing time signs and symptoms of
possible complications as well as wearing schedules.

A

written

43
Q

Rigid lenses that are not worn for long periods of time should be
stored …

A

dry

44
Q

rigid lens wear: sharp pain upon instertion or suddenly

A

foreign body, damaged lens

45
Q

Soft lens wear: pain after several hours of wear

A

poor fit

46
Q

rigid lens wear: pain after several hours of wear

A

lens rubs the cornea, either centrally due to flat lens/ cornea relationship, or peripherally due to poor edge.

47
Q

corneal tomography

A

produces high-resolution imaging of the cornea,iris, and anterior chamber (eye ultrasound)

48
Q

burning upon insertion

A

reaction to solution

49
Q

Soft lens wear: burning after several hours of wear

A

Tight lens, improper blinking

50
Q

Rigid lens wear: burning after several hours of wear

A

improper blinking, tight fit, poor lens movement

51
Q

Soft lens wear: excessive blinking

A

Lens awareness, lens damage

52
Q

Rigid lens wear: excessive blinking

A

lens awareness

53
Q

Rigid lens wear: excessive tearing

A

damaged or dirty lens

54
Q

Soft lens wear: excessive tearing

A

lens damage

55
Q

Soft lens wear: itching

A

allergic reaction to solutions, lens deposits, or material

56
Q

Rigid lens wear: itching

A

allergic reaction to solutions, environment, or material

57
Q

Rigid lens wear: scratchy feeling

A

foreign body,lens damage, improper edge design

58
Q

Soft lens wear: scratchy feeling

A

foreign body,lens damage, lens deposits, edge standoff

59
Q

Rigid lens wear: photophobia

A

edema, dirty lens, corneal abrasion

60
Q

Soft lens wear: photophobia

A

edema, dirty lens

61
Q

poor visual acuity

A

dirty lens, switched lenses, corneal changes

62
Q

Rigid lens wear: foggy or smokey vision

A

edema, dirty lens

63
Q

Soft lens wear: foggy or smokey vision

A

edema

64
Q

Rigid lens wear only: flare

A

too small optical zone, decentration, large pupil

65
Q

Rigid lens wear: ghost images

A

residual astigmatism, warped lens

66
Q

Soft lens wear: ghost images

A

residual astigmatism, oily film on lens

67
Q

headaches

A

wrong power, edema

68
Q

problems reading

A

wrong power, onset of presbyopia

69
Q

Every ____mm of radius equals approximately ____diopters.

A

0.05
0.25

70
Q

Slit lamp filter that enhances the view of fluorescein dye in the eye’s tear film. Typically used for fluorescein staining and Goldmann tonometry

A

Cobalt blue

Symbol: Blue filled Circle

71
Q

Slit lamp filter used to enhance the view of blood vessels and hemorrhages

A

Red free

Symbol: green filled circle

72
Q

Slit lamp filter that decreases maximum brightness for photosensitive patients

A

neutral density

Symbol: Circle with hashed lines

73
Q

Slit lamp filter that decreases patient discomfort

A

Head absorbing

Built in to slit lamp

74
Q

Slit lamp filter that decreases maximum brightness for photosensitive patients

A

Grey

Symbol: Circle with thick line

75
Q

Slit lamp filter good for contrast enhancement when using fluorescein and cobalt blue filter.

A

Yellow filter

Symbol: Yellow filled circle located in the observation system

76
Q

Slit lamp filter used for general overall observations of the eye and adnexa

A

Diffuser

Symbol: May be a flip-up filter placed on the illumination source

77
Q

A … in the optic zone flattens the fit by enlarging the peripheral curve.

A

decrease

78
Q

A decrease in sagittal vaulting creates a … lens to cornea relationship.

A

flatter

79
Q

Decreasing the overall lens diameter also … the sagittal depth.

A

decreases

80
Q

When classic keratometry is performed by having the patient sight on the mirrored image of their eye, alignment of what is accomplished

A

The optical axis with the visual axis

81
Q

Inadequate limbal coverage change diameter

A

Mess with diameter

82
Q

Sam and fap is swapped when

A

Effective power is used
Fam and sap

NCLE Prep (26 decks)

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