Exam 1 Material Flashcards
(140 cards)
1
Q
What are the 3 requirements for binocular vision?
A
- Corrected refractive error
- Motor fusion
- Sensory fusion
2
Q
What drop is used for a “damp” refraction?
A
Tropicamide
3
Q
What drop is used for a “wet” refraction?
A
Cycloplegic drop
4
Q
What is mohindra?
A
Near point retinoscopy used for infants
Monocular, in a dark room
Infant looks at light
1.25 D working distance
5
Q
What kind of blur would a moderate hyperope experience?
A
Near point blur
6
Q
What kind of blur would a moderate myope experience?
A
Distance blur
7
Q
What is heterophoria?
A
Natural deviated resting position of dissociated eyes
8
Q
What is fusional vergence demand?
A
Amount of motor fusion needed to compensate for phoria that is present
9
Q
What type of convergence errors are esophoria and exophoria?
A
ESOphoria - OVER convergence when dissociated
EXOphoria - UNDER convergence when dissociated
10
Q
What type of fusional vergence compensates for ESOphoria?
A
NFV
Negative Fusional Vergence
11
Q
What type of fusional vergence compensates for EXOphoria?
A
PFV
Positive Fusional Vergence
12
Q
What is the term for eyes that have normal alignment under dissociated conditions?
A
Orthophoria
13
Q
What 3 symptoms does poor motor fusion create?
A
- Diplopia
- Fatigue
- Blur
14
Q
In terms of accommodation, what helps with an eso deviation?
A
Relaxing accommodation
Plus lenses
15
Q
In terms of accommodation, what helps with an EXO deviation?
A
Stimulating accommodation
Minus lenses
16
Q
What allows for the foundation of stereopsis?
A
Two eyes with two different visual directions
17
Q
What are the Big 6 of the binocular exam?
A
- Refractive Error
- Phoria
- Accommodation
- Vergence
- Oculomotor skills
- Fusion
18
Q
What equipment can be used to screen and check if the patients tentative Rx is appropriate?
A
+/- 2.00D Flipper
19
Q
What is the scale that gives a functional number for cover test, rather than just the magnitude of deviation?
A
Mayo Control Scale for XT
20
Q
What is the expected AC/A ratio if near is relatively more EXO (>5 prism diopters) than distance?
Low or high?
A
Low AC/A
This is me
21
Q
What is the expected AC/A ratio if near is relatively more ESO (>5 prism diopters) than distance?
Low or high?
A
High AC/A
22
Q
What is the difference between comitant and non-comitant phoria?
A
Comitant: Constant phoria in all positions of gaze
Non-Comitant: Phoria changes with position of gaze
23
Q
If a patient is more ESO at near while performing kinetic cover test, is their expected AC/A high or low?
A
High AC/A
24
Q
Is the “Push-up” or “Pull-away” test better for patients that don’t understand the concept of blur?
A
“Pull-away” test
Instruct patient to say when line is clear
25
What is the MINIMUM expected accommodative amplitude of a patient as described by Hoffsteter's formula?
```
15 minus (0.25 x patient age)
Example: 20 year old
15 - (0.25x20) = 15-5 = 10D
```
26
At what distance should MEM retinoscopy be performed?
At reading distance for the patient
27
What does it mean to have accommodative lag?
Patient is using LESS accommodation than necessary
28
What does it mean to have accommodative lead?
Patient is using MORE accommodation than necessary
29
If a patient views the HORIZONTAL lines as darker in Binocular Cross Cylinder testing:
What is happening with accommodation?
What corrective lenses should be used?
Accommodative LAG
| Plus lenses
30
If a patient views the VERTICAL lines as darker in Binocular Cross Cylinder testing:
What is happening with accommodation?
What corrective lenses should be used?
Accommodative LEAD
| Minus lenses
31
Is accommodative LAG or accommodative LEAD the expected normal value?
Accommodative LAG
32
What should be used as a suppression check for accommodative facility testing?
Red/Green Bar Readers
33
How long should accommodative facility be tested?
One minute
34
What is an example of a "smooth" vergence range measurement?
Risley prism
35
What is an example of a "step" vergence range measurement?
Prism bar
36
What are 3 examples of oculomotor skills to test?
1. Fixation
2. Saccades
3. Pursuits
37
What does Worth 4 dot testing measure?
Presence and/or size of scotoma
38
What is a requirement for a global stereopsis test?
Must be bifoveal
39
What is the absence of fusion?
Suppression
| No depth perception
40
What is an example of a patient where prescribing the full Rx would negatively impact posture?
Uncorrected hyperope w/ significant exo posture
41
What are 2 important considerations for performing static retinoscopy on pediatric patients?
1. Bracket
| 2. Be fast and precise
42
Mohindra is typically performed monocularly. What is an example of where it would be performed binocularly?
Infants
43
What is a common error of autorefractor readings?
Over-minusing of patients
44
When is an autorefractor useful for rechecking a prescription?
After cycloplegic drops
45
When is a handheld autorefractor useful?
Wheelchair bound patients
| Young or small patients
46
Why is a cycloplegic refraction used?
To control accommodation
47
What are the 3 most common cycloplegic agents?
1. Atropine
2. Cyclopentolate
3. Tropicamide
48
What is the most potent cycloplegic agent and how long does it last?
Atropine
| 1 week
49
How long do the effects of cyclopentolate last?
24 hours
50
For about how long do the effects of tropicamide last?
4-6 hours
51
How much residual accommodation is left when using tropicamide?
About 5 diopters
52
How much residual accommodation is left when using cyclopentolate?
0.75 diopters
53
What type of drug is cyclopentolate and what is its action?
Anticholinergic
| Inhibits iris sphincter and ciliary muscle
54
What is pseudomyopia caused by?
Spasm of the ciliary muscle
55
What should dosage of cyclopentolate be for patients under 1 year old?
Over 1 year old?
Under 1 - 0.5% cyclopentolate
| Over 1 - 1.0% cyclopentolate - 2 drops 5 mins apart
56
What are some adverse reactions to cyclopentolate to be aware of?
Blur, photophobia (expected)
Increased IOP if angle closes
Seizures, behavior change, cardiac problems
57
What are 5 types of patients to monitor closely if cyclopentolate is used?
1. New patient
2. Previous adverse reaction
3. Frail cardiovascular system
4. Compromised CNS (Down's, TBI, etc...)
5. Narrow anterior chamber angle
58
What does a binocular refraction allow for greater control of?
Accommodation
| Also, more accurate endpoint for cylinder axis
59
What are 3 techniques of refraction that do not require blur balance as an additional step?
1. Septums (infinity balance)
2. Polarized slides (vectographic)
3. Fogging (Humphriss)
60
What is true of most hyperopic infants?
They will stay hyperopic, but the extent will lessen
61
What is true of most myopic infants?
They will become hyperopic and then proceed into myopic during the school age years
62
Are hyperopes or myopes at higher risk of developing amblyopia?
Hyperopes
63
When should you prescribe lenses for hyperopes?
Greater than +2.00D at any age
64
What should you prescribe lenses for myopes?
Greater than -3.00D for 1-3 year olds
| Greater than -1.00D for all over 3 years old
65
When should you prescribe lenses for astigmats?
Greater than -1.25D of cyl
66
What is the goal of case analysis?
Evaluate all exam data to make a diagnosis
67
What is very important for all BV patients?
Management of symptoms
68
What are the 3 steps of the integrative analysis approach?
1. Compare tests to tables of expected findings
2. Group findings that deviate from expected results
3. Identify the syndrome
69
What specific norms are we using for this class?
Morgan's norms
70
What syndromes are associated with LOW AC/A?
Insufficiencies
| convergence and divergence
71
What syndromes are associated with HIGH AC/A?
Excess
| convergence and divergence
72
What is the near triad?
Convergence
Accommodation
Miosis
73
What is the formula for calculated AC/A?
```
PD + (NFD)(Hn-Hf)
NFD = Near Fixation Distance in meters
Hn = Near Phoria
Hf = Distance Phoria
All eso is plus
All exo is minus
```
74
Where is gradient AC/A performed?
At near
75
What is CA/C ratio?
Convergence Accommodation/ Convergence
76
What are direct tests for PFV and NFV?
Smooth and step BO and BI ranges
77
What will all direct tests of accommodation be?
Monocular
78
Are convergence problems near or distance problems?
NEAR problems
79
Are divergence problems near or distance problems?
DISTANCE problems
80
What is the definition of fixation disparity?
Small angle of misalignment of the eyes under binocular conditions
81
What is required to be occurring for fixation disparity to be present?
Fusion
82
In order for fusion to be present, where must the amount of inaccuracy be within?
Panum's Fusional Area
83
Where in Panum's Fusional Area are patients more likely to experience symptoms with fixation disparity?
Near the edges of Panum's Fusional Area
| Results from larger magnitude fixation disparity
84
What type of fixation disparity is a patient with esophoria likely to have?
Eso fixation disparity
85
What is a 'slang' term for fixation disparity as related to the visual system?
"ready position"
86
What are 5 examples of methods/equipment that measure fixation disparity?
1. Mallet Box
2. Disparometer
3. Borish Card
4. Wesson Card
5. Saladin Card
87
What is a very precise method of measuring fixation disparity?
Disparometer
88
What 3 things must all measuring methods of fixation disparity provide?
1. Binocular fusion lock
2. Two monocular nonius lines
3. Natural conditions (not dissociated)
89
What does the x-axis of a fixation disparity curve measure?
Prism amount in prism diopters
90
What does the y-axis of a fixation disparity curve measure?
Magnitude of fixation disparity in arc minutes
91
What is the x-intercept of a fixation disparity curve and what are its units?
Associated phoria
| prism diopters
92
What is the y-intercept of a fixation disparity curve and what are its units?
Magnitude of fixation disparity
| arc minutes
93
What is significant about the associated phoria?
The amount of prism diopters needed to reduce the fixation disparity to ZERO
94
Where is the slope for a fixation disparity curve observed?
Between 3 BO and 3 BI
95
What does a steeply sloped fixation disparity curve signal?
Poor ability to adapt to prism
96
What does a fixation disparity curve with a flat slope signal?
Good ability to adapt to prism
97
What type of curve do most patients show with a fixation disparity curve?
Type 1
98
What does a type 2 curve look like and what does it signify?
Looks like an L
Poor adaptation to BI prism
Esophoria usually present
99
What does a type 3 curve look like and what does it signify?
Looks like a 7
Poor adaptation to BO prism
Exophoria usually present
100
What does a type 4 curve look like and what does it signify?
Looks like a Z
| Poor sensory or motor fusion
101
What 2 things are a fixation disparity curve useful for?
1. May help uncover a BV problem not found with other tests (symptomatic patient without signs)
2. Monitoring vision therapy progress
102
What are the 4 steps in the order of evaluation?
1. Comprehensive Eye Exam
2. Binocular Vision Follow Up
3. Treatment Decision
4. Follow Up/ Monitor
103
What is the main goal for treatment of accommodative and non-strabismic disorders?
Overcoming symptoms
104
What are the 2 main BV symptom surveys?
1. Convergence Insufficiency Symptom Survey
| 2. COVD QOL Survey
105
What is the purpose of a symptom survey?
Can be used to show measurable decreases in symptoms
106
What is extremely important in the prevention of amblyopia or strabismus?
Early detection
107
In order from least invasive to most invasive, what are the 6 parts of the sequential management approach for amblyopia?
1. Optical correction of ametropia
2. Added lenses
3. Prism
4. Occlusion
5. Vision therapy
6. Surgery
108
Is there an age limit on treatment of amblyopia?
NO
| Example - Stereo Sue
109
When does rapid emmetropization occur?
Infancy
| very noticeable between 3 and 9 months
110
When is it always important to prescribe a myopic Rx?
When patient has significant refractive error
| When patient is an exotrope (especially when intermittent)
111
What should you be careful with when prescribing plus lenses?
Don't want to make the patient exo
112
What is an important consideration when prescribing astigmatic correction?
Astigmatism should be deemed stable before prescribing for it
113
During what span of life are larger amounts of astigmatism common?
Less than 3 years old
114
What types of astigmatism are more stable?
With the Rule
| Oblique
115
What amount of anisometropia presents a large risk for amblyopia?
Greater than 3 diopters at 1 year old
116
Where should the bifocal line be measured for on a 3-5 year old patient?
Pupil center
117
Where should the bifocal line be measured for on a 6-7 year old patient?
Lower pupil
118
For any patient older than 8 years of age, where should the bifocal line be measured?
Lower lid margin
119
What amount of prism should you prescribe for any given patient?
The least amount needed to come to the desired result.
120
How does Sheard suggest the Compensational Fusional Vergence should relate to the phoria of a patient?
CFV should be twice the phoria
121
What is the formula for Sheard's Criterion?
Prism needed = (2/3 phoria) - (1/3 CFV)
122
How should prescribed prism be split between eyes?
Half and half
| Example 4 BI total would be 2 BI OD and 2 BI OS
123
For what type of phoria is the 1:1 rule mostly used for?
ESOphoria
124
What does the 1:1 Rule state?
Recovery is greater than or equal to the phoria
| or the patient may have symptoms
125
What amount of vertical prism is clinically significant?
0.50 prism diopters
126
Should prescribed prism allow for fusion all the time?
Should allow for fusion MOST of the time
| Remember, Rx the least amount possible for relief of symptoms
127
How long should patching occur in cases of moderate amblyopia?
2 hours a day
128
How long should patching occur in cases of severe amblyopia?
6 hours a day
129
What is the long term goal of vision therapy?
```
To develop normal:
Sensory fusion
Motor fusion
Accommodative skills
Oculomotor control
```
130
What amount of horizontal deviation may warrant surgical intervention?
Greater than 30 prism diopters
131
What is the Relative Point Value with respect to add determination?
The difference in dioptric power from the patient's BVA (therefore BVA=0)
132
What is the formula for balancing the NRA and PRA to determine the add for a patient?
(NRA+PRA)/2 + RPV
133
Should NRA be a positive or negative value?
Positive
134
Should PRA be a positive or negative value?
Negative
135
How does a high AC/A impact PRA?
High AC/A lowers the potential PRA with all else the same
136
When training BI values, what vergence direction is being trained?
Divergence
137
When training BO values, what vergence direction is being trained?
Convergence
138
What kind of lenses make divergence more difficult?
Minus lenses
139
What kind of lenses make convergence more difficult?
Plus lenses
140
What is the normal AC/A ratio based on Morgan's Norms?
4/1
