Low Vision 1

Front 1

The goal of vision rehab is _____.

Back 1

functional

Front 2

1. what is: the consequence to the bodily organ affected
2. what is: describes the consequence to the patient; lack, loss or reduction of an individual's ability to perform certain tasks
3. what is: consequence to the patient in terms of their interaction with the society in which they live
4. what is: actual damage of the anatomical structure or physiological function of the eye

Back 2

1. impairment (VA and VF measure this)
2. disability
3. handicapp
4. disorder

Front 3

Dr. Oliver prefers a _____ definiteion of low vision--> as vision that is not adequate for the person's needs

Back 3

functional

Front 4

What act (and year) defines legal blindness?

Back 4

Social Security Act in 1935

Front 5

What is the definition of legal blindness used in the U.S.?

Back 5

BCVA in the better eye less than or equal to 20/200 OR the visual field is less than or equal to 20 degrees in the widest diameter

Front 6

What is the difference between the definition for the SSA and IRS?

Back 6

The SSA allows acuities between 100-200 and the IRS only allows 20/200 or worse

Front 7

Is 20/125+1 considered legally blind?

Back 7

No!

Front 8

Which Humphrey VF test (kinetic perimeter) is allowed to define legal blindness?

What decibel stimulus must you use for automated static threshold perimetry?

Back 8

SSA Test Kinetic

10dB (= a 4e stimulus)

Front 9

T or F: If a person has a visual field horizontal radius of 12 degrees and a 10 degree vertical radius, they are legally blind (regardless of VA)

Back 9

F! RADIUS vs. DIAMETER

Front 10

T or F: compared to other ages/races, 75+ blacks have the highest prevalence of visual impairment

Back 10

T

Front 11

The Framinham eye study found that blindness and visual impairment were higher in which gender? Also, visual impairment increased with what?

Back 11

Female; age

Front 12

In the Mud Creek eye study, what were the 2 leading causes of legal blindness?

Back 12

cataract and ARMD

(glaucoma is the other leading cause but this study didn't evaluate it)

Front 13

Which eye study was the first to evaluate blindness in an urban, multiracial population?

Back 13

Baltimore Eye Study

Front 14

T or F: according to the Salisbury eye evaluation, VA, contrast and glare sensitivity, stereo acuity and visual fields all decline with age

Back 14

T

Front 15

What are 3 risk factors for visual impairment?

Back 15

Age, ethnic background, socio-economic status

Front 16

Most low vision practitioners feel the ____ should take the Hx.

Back 16

clinician (to develop rapport)

Front 17

____________- understanding the environment so they are comfortable with it

___________- the ability to get around in their environment saftely and independently

Back 17

orientation

mobility

Front 18

Personal hygiene, cooking, cleaning and communication are all part of what category that needs to be asked in a thorough case Hx?

Back 18

Activities of Daily Living

Front 19

What are the two starred categories on the Case Hx lecture which are very important?

Back 19

Expectations and establishing realistic goals

Front 20

4 methods for specifying visual acuity are?

which one is universally used in most clinical settings?

Back 20

Detection, Pattern Resolution (contrast sensitivity), Localization (vernier actuity or stereo), Recognition

recognition (snellen/landolt C)

Front 21

What's the minimum angle of resolution that a normal human eye should see?

Back 21

1 minute of arc

(20/20)

Front 22

An _____ progression of the denominator will result in an overcrowing at the large letter end of the chart

_____ progression of decimal acuity like (.1, .2) gives over representation at the small letter end of the chart (Snellen)

______ progression (Bailey-Lovie) uses MAR and uses an arithmetic progression in the logarithm of MAR

Back 22

Arithmetic

Linear

Geometric

Front 23

The logMAR chart (ETDRS) has a progression of letters by a size factor of ____, so every 3 steps or 4th line will be a factor of ___ times.

Back 23

1.26

2X (6 steps is 4x and 9 steps is 8x)

Front 24

Differences of low vision charts vs. projector charts? (3 of them)

Back 24

1. moveable
2. more letter sizes
3. better contrast

Front 25

Which VA chart has separation between optotypes and between rows standardized to be proportional to the size of the optotype (giving the chart a triangular appearance)

Back 25

ETDRS

Front 26

If a 78 y.o. patient using the ETDRS chart has BCVA at the 20/200 line at one meter and the trial frame reads +3.50, what is the final Rx they need for distance?

Back 26

+2.50! Take away +1.00 since that's what an absolute presbyope needs to see the chart at 1 meter.

Front 27

For M notation, a 1M letter subtends ___ minutes of arc at 1 meter. A 1M letter is ___mm tall. What is the snellen equivalent? What is the point size of a 1M letter?

Back 27

5

1.45

20/50

8 pt

Front 28

What type of progression does the ETDRS chart use?

Back 28

Geometric (logarithmic progression and proportional spacing)

Front 29

The lighthouse game card and continuous text card both use geometric progression but what phenomenon happens?

Back 29

crowding

Front 30

The Beaver Dam Eye study found that visual impairment is ____ times the amount of people who are legally blind

Back 30

3-4

Front 31

________ is the leading cause of NEW blindness in adults

Back 31

diabetes

Front 32

Illumination should be ___ and ____. What can aid in eliminating one of these?

Back 32

uniform and glare free

back illuminated charts (for glare)

Front 33

T or F: There is never a situation that you would want to test VA with dim levels of illumination

Back 33

F! (ex: cone abnormalities)

Front 34

What is the difference between Preferred retinal locus (PRL) and eccentric viewing (EV)?

Back 34

With PRL, the patient doesn't attempt to foveate and automatically goes to an extrafoveal point. With EV, an attempt to foveate is made and then a search for an extrafoveal point

Front 35

How do you record the angle of EV?

Back 35

From the PATIENT'S perspective (OS superior temporal position is 11:00)

Front 36

Why would a person have multiple PRLs?

Back 36

Viewing a distance target is different than viewing a near target...near PRL may be further from central scotoma to get a good clear image...that's why it's important to determine magnification from near acuity and not distance acuity

Front 37

What type of visual field defect might show better acuity with smaller letters?

Back 37

visual field constriction (shorter testing distance might cut off some of the larger letter sizes making it harder to see them)

Front 38

What are the testing distances for the ETDRS chart?

Back 38

4, 2, 1

Front 39

T or F: you cannot record finger counting as a visual actuity

Back 39

T

Front 40

How would you record this:

The patient's VA is tested with the left eye on the Feinbloom chart at 10ft. and they can see a 120 optotype with eccentricly viewing temporally to the actual letter

Back 40

OS 10/120 Feinbloom EV 9:00

4 things!

Front 41

T or F: if you need to equate a 10/60 visual acuity with the left eye (Feinbloom chart and no EV) as a Snellen equivalent for reporting purposes, record it as:
OS 20/120 Feinbloom no EV

Back 41

F!!! have to say the real VA and testing distance and then can put Snellen equivalent at the end of the line

OS 10/60 Feinbloom no EV S.E. 20/120

Front 42

T or F: When evaluating near acuity, single letter acuities should be evaluated until threshold is reached

Back 42

T

Front 43

Paul Freeman technique for patients having difficulty with the clock dial technique for EV: if the patient looks straight ahead (both eyes open) and the patient reports optimal VA with the chart moved directly to the right, what is the Ev recorded?

Back 43

9:00

Don't forget to do this monocularly and binocularly!

Front 44

If the uncorrected VA is better than the corrected VA, what objective test should you do?

Back 44

Keratometry

Front 45

What frequently dampens pendular nystagmus? (Which will help for trying to do keratometry)

Back 45

Convergence

(Need to find the null point)

Front 46

How should retinoscopy be performed on a low vision patient?

Back 46

With the trial frame or Halberg/Janelli clips

Front 47

If you do over refraction using a Halberg clip over spectacles to find the Rx, how do you find the final new power?

Back 47

Put the system in a lensometer! Can't just add things together if not on the same axis

Front 48

What are the two methods to measure vertex distance on a trial frame?

Back 48

The scale of the TF or a distometer

Front 49

Kestenbaum method: The add required to read 1M at near is equal to the ?

Modified Kestenbaum?

Back 49

reciprocal of the distance VA

reciprocal of the distance VA multiplied by 1.5

Front 50

Sloan M Notation Method (Dr. O prefers):

What is the add for this pt to allow them to read a 1M letter: They can read a 4M letter at 40cm.

Back 50

4M x 2.50 (the add allowing them to read at 40cm)= +10 add

Front 51

T or F: both Kestenbaum methods use the near VA to find the predicted add

Back 51

F!!! distance VA!

Front 52

In a patient with new onset macular changes, if they report that words are running together when reading or that the print appears blurry even tho they are at the right distance, what might be occuring and what should they do when reading?

Back 52

Retinal rivalry; occlude one eye for that task

Front 53

Patients acuities that differ by a factor no more than ____ need to have binocularity invegstigated (certain advantages)

Back 53

1.5

ex: 20/40 and 20/60

Front 54

Cover test, Hirschberg and vergence testing all test what aspect of binocular vision in low vision patients?

Back 54

motor

Front 55

Worth 4-dot, Red filter/Maddox rod, Prism test and Stereo testing all test what aspect of binocular vision in low vision patients?

Back 55

sensory

Front 56

If the patient reports that the Fly or Reindeer is popping out of the page, the patient has ___ stereopsis. That means you can test finer levels of stereo using ___ or ____.

Back 56

gross; animals or wirt circles (random dot tend to be harder)

Front 57

What are the 4 categories of Eleanor Faye's approach to functional loss?

Back 57

1. no field defects but blur throughout field
2. no field defects but reduced vision at fovea
3. central field defects
4. peripheral field defects

Front 58

What 4 areas of the eye will lead to blur across the entire field with no scotomas?

What are the main difficulties (complaints) in these people?

What are some devices you should recommend to reduce the complaints?

Back 58

Cornea, Pupil, Lens, Vitreous

Glare (Veiling glare= disability glare) and poor contrast discrimination (major problem for traveling outdoors)

Wide brim hats, clip on sunglasses, absorptive lenses like neutral gray, YELLOW, red

Front 59

For a person with no field defects but reduced vision involving the fovea only:
1. what are two major conditions this occurs in?
2. what is major complaint?
3. what are tx options?

Back 59

1. Achromatopsia and Albinism
2. lack of distance acuity (and glare especially in albinism)
3. all types of absorptive lenses and illumination control (placing of light sources and wearing hats)

Front 60

Retinal disease marked by _______________________ is the most common cause of non-refractice visual impairment seen in a general eye practice.

Back 60

central or paracentral scotomas

Front 61

The main conditions causing scotomas of the central retina (30 degrees of posterior pole) are what?

Back 61

Macular degeneration (dry and wet) and neovascular membranes

Front 62

T or F: atrophic ARMD usually has a favorable response to optical/visual devices whereas exudative ARMD has a guarded prognosis with these devices

Back 62

T

Front 63

T or F: Patients with central scotomas and VA of 20/50-20/400 will have more problems with mobility than reading

Back 63

F!! opposite

Front 64

What devices can we suggest for the patient with central scotomas?

Back 64

large print material, adequate illumination, sunglasses and a magnifying device (all types)

Front 65

What are some conditions associated with peripheral field defects?

Back 65

RP, rhegmatogenous RD, Demyelinating dz (MS), CVA, diabetes, proliferative ret, post-PRP, glaucoma

Front 66

T or F: in a patient with peripheral field defects, bringing an object closer to their eye will help in detection

Back 66

F! less information as they bring the object closer

Front 67

T or F: mobility is more difficult than reading in patients with peripheral field defects

Back 67

T

Front 68

T or F: beyond 20/400, as in the case of someone with an island of useful vision at the equator of the eye, the prognosis for reading is poor and magnification devices have a poor prognosis

Back 68

T

Front 69

Difficulties in mobility and other activities occur when field is restricted to ____ degrees in the widest diameter.

Back 69

10

Front 70

When considering attempting visual field ENHANCEMENT, visual field testing is not enough. What is the other important factor? How do you evaluate it?

Back 70

Functional ability; careful patient history (is loss due to VA or field?)

Front 71

What are the 5 techniques and devices to ENHANCE the visual field?

Back 71

Scanning, reverse telescopes, fresnel prisms, mirrors, concave lenses

Front 72

Although a 2X reverse telescope will provide twice the field, what's the disadvantage?

BUT: what's the purpose of the reverse telescope?

Back 72

the image is minified by the same amount (reducing VA by the power of the telescope)

To enhance MOBILITY (not read an acuity chart)

Front 73

What's the most successful form of therapy for field enhancement?

How many prism diopters are needed for a noticeable effect?

Back 73

Fresnel prism

15-25 degrees

Front 74

What is the major disadvantage of using mirrors to enhance the visual field?

What patients might they be better for?

Back 74

they block some of the remaining useful field

Those needing a larger shift in image (increased prism = increased chromatic aberration)

Front 75

Concave lenses work like ____ ____ (another visual field enhancer). You are essentially making what kind of device?

Back 75

reverse telescope

reversed Galilean telescope

Front 76

T or F: a patient must have sufficient accommodation to use a concave lens or else an add is required

Back 76

T

Front 77

What type of prism is used for a bedridden patient to view the TV?

Back 77

NAP prism (?)

Front 78

T or F: glaucoma is twice as prevalent as ARMD

Back 78

F! opposite

Front 79

T or F: contrast deficits may be present even when VA appears normal

Back 79

T (that's why you should test contrast sensitivity)

Front 80

Sensitivity= ?

What's normal peak sensitivity for humans?

Back 80

1/threshold

4cpd

Front 81

Which person will have more problems with mobility: a person with a low SF deficit or high SF deficit?

Back 81

low SF

Front 82

According to Pizzimenti's lecture, when should you occlude one eye to improve VA/CSF? (3)

Back 82

1. unequal metamorphopsia
2. subjective response to occlusion
3. CSF shows no binocular summation

Front 83

What are two tests for evaluating glare?

Back 83

brightness acuity test and photostress recovery test

Front 84

What's the most useful method in low vision for evaluating the peripheral visual field?

Back 84

Goldmann/ARC Perimetry

Front 85

Which visual field analyzer uses hyperacuity stimuli?

What portion of the VF does it test?

Back 85

PreView PHP

central 14 degrees

Front 86

Laser interferometry assesses the endpoint grating acuity by finding the ___ ___ ____ or highest SF at max contrast

Back 86

spatial resolving limit