low vision assessment

Question 1

name 3 things that you observe about a patient in your lv clinic

Answer 1

• postural abnormalities
• mobility
• appearance

Question 2

what is the most important part of a low vision assessment

Answer 2

history taking

Question 3

how is a lv history taking different to a pcc history taking

Answer 3

more follow up questions are asked and more time is spent on it

Question 4

list 9 things you will ask about in history taking of your lv assessment

Answer 4

• the duration of condition and onset
• stability of condition and differences between the eyes
• patients knowledge of the condition and prognosis
• ongoing hospital monitoring and or treatment
• registration status
• education and or employment
• present aids and spectacles
• general health and medications
• reason for making the appointment

Question 5

why will you ask the patient about their knowledge of the condition and prognosis, during history taking

Answer 5

as the patient needs to understand the eye condition to know how to deal with it and they will know if the condition will deteriorate so they can adjust to it well

Question 6

why will you need to know if a lv patient is on any ongoing hospital monitoring and or treatment

Answer 6

to know if you should prescribe glasses or not
and you dont want to dilate the patient unless they’re having a new symptom, because if they’re at the hospital then they are getting dilated already, but if they’re not then you must dilate

Question 7

why will you want to know about a patients registration status during history taking

Answer 7

to know if they’re SI or SSI
and you want to know if they have access to any benefits e.g. social services
if not you may need to follow up with them or refer them to be registered

Question 8

why will you want to know about a patients education status during history taking

Answer 8

if its a child, you want to know if they’re in an ordinary or a specialist school

Question 9

why will you want to know about a patients employment status during history taking

Answer 9

incase you need to tell them about the access to work scheme

if they’re employed they can use lv aids at work

Question 10

why will you want to know about present aids and spectacles during history taking

Answer 10

to know if the aids/spectacles have been working in order to avoid wasting your patients time

Question 11

why will you want to know about a patients general health and medications during history taking

Answer 11

to know which aid to give e.g. patient may have arthritis or Parkinson’s therefore they cannot hold a magnifier and you will want to give glasses instead etc

Question 12

why will you want to know about a patients reason for making the appointment during history taking

Answer 12

you don’t want to assume that the px made the appointment themselves
sometimes they don’t know why they have made the appointment, as in the UK, the patient will be referred by the ophthalmologist and they don’t know why they came to the clinic

Question 13

why do you want to ask about distance vision to your lv patient during history taking

Answer 13

• difficulty seeing: faces, buildings, cars, street signs, road signals, bus numbers and steps
• vision fluctuates or not
• eccentric viewing status
• problems with glare: wears tinted glasses
• vision better outdoors/indoors

Question 14

which type of eye conditions will a lv px have if they have difficulty seeing faces

Answer 14

AMD or stargart’s / any macula problem

Question 15

why would you want to know if a patients distance vision fluctuates or not during history taking

Answer 15

because you want to be aware, incase you give the wrong lv aid or glasses

Question 16

why would you want to know about a patients eccentric viewing status during history taking

Answer 16

because if they dont use this technique, then you can give advice on how to use it for e.g. AMD or stargart’s patient management

Question 17

why would you want to know if vision is better outdoor or indoor during history taking

Answer 17

as this can cause a fluctuation in vision and this can impact on what LVA you give to the px

Question 18

what do you want to know about a patients mobility in the lv clinic

Answer 18

does the patient walk alone, or accompanied in new/familiar environments

Question 19

give an example of a px who will have problems with mobility in unfamiliar environments

Answer 19

px who’s had a stroke and got a hemianopia

Question 20

list 4 things you want to ask about a patients home situations during history taking

Answer 20

• if the patient lives alone or with family
• if they have difficulty getting around the house
• if they have difficulty watching tv
• if they have difficulties with colours

Question 21

why would you want to ask a lv patient is they live alone or with family in your history taking

Answer 21

• if lives alone, they may need additional help e.g. with reading letters etc
• if lives with family, you know that support is easier for them

Question 22

what 3 things will you ask your lv px during history taking about reading, close work and hobbies

Answer 22

• do they have difficulties seeing books, newspapers, headlines, large print, own writing
• is vision better in dim light or bright light
• do they have difficulties with hobbies such as sewing, bingo etc

Question 23

why would you want to ask your lv px about their reading during history taking

Answer 23

it is one of the main problems a lv px faces, especially the elderly as they tend to stay at home and read

Question 24

why would you want to ask your lv px about their hobbies during history taking

Answer 24

to know how to best help the px

Question 25

whats a good idea to do at the end of history taking

Answer 25

make a list of the patients priorities in order to know what help the patients wants then summarise your findings to the patient and offer help by asking the patient

Question 26

what is the next thing to do in your lv assessment after history taking

Answer 26

measure visual acuity

Question 27

record visual acuity ____________ then ___________ ______ and ___________ aid

Answer 27

record visual acuity monocularly then binocularly with and without aid

Question 28

where is it best to start testing va's

Answer 28

a close distances and then modify

Question 29

what must you never resort to when measuring va's and why

Answer 29

contain fingers | because if the px can read 6/60 at 1m then they can definitely see counting fingers at 1m, so don't resort to it

Question 30

give an example of how precisely va should be recorded

Answer 30

3/60 instead of

Question 31

if a lv patient does not have a previous va history, how must you start

Answer 31

start at 3 metres as this is a positive start and the patient is most likely to read

Question 32

when measuring near vision on your lv px, what 2 things must you do/record

Answer 32

- distance at which near vision assessment was made | - measure reading speed if possible

Question 33

why must you measure the distance at which near vision assessment was made

Answer 33

because for example, N40 at 40cm can be different to N40 at 20cm so must record working distance

Question 34

what must you make sure of when measuring near vision of your lv px

Answer 34

that field of illumination is uniform and glare free | reading charts should not be laminated

Question 35

give an example of how you will record distance VA unaided

Answer 35

if px wears glasses then record their unaided va's with glasses RE: 3/60 LE: 2/60 BE: 3/60

Question 36

give an example of how you will record distance VA with an lv aid

Answer 36

distance va with (Eschenbach telescope, 6x) used with RE | RE: 6/9

Question 37

give an example of how you will record near VA unaided

Answer 37

``` Near va (reading glasses)/MNREAD charts RE: N36 LE: N36 BE: N36@ 40cm ```

Question 38

give an example of how you will record near VA with an lv aid

Answer 38

near va with (Eschenbach HM, 6x) | N6 at 12cm

Question 39

after measuring visual acuity, what is the next step to your lv assessment

Answer 39

determine refractive error

Question 40

when may you observe a dull reflex on your lv px during retinoscopy and what will you need to do

Answer 40

if the px has cataract | you need to move closer

Question 41

what can you do in difficult cases of retinoscopy when you can see the reflex at all

Answer 41

use old glasses as a guide, but be careful

Question 42

why is it a good idea to use a trial frame and full aperture lenses when determining refractive correction on your lc px

Answer 42

it is easier to see their facial expressions while testing, which you can't with a phoropter

Question 43

what can you use for high refractive errors whilst determining your refractive correction

Answer 43

Harlberg clips where you refract over the patients glasses used if can't see ret reflex and want an idea of px's rx and then do subjective that way

Question 44

what steps of spheres and cross cyls should you use when refining your rx when determining the refractive correction of your lv px

Answer 44

+/- 2DS spheres +/-1DC JCC px has low va's so can't appreciate small steps

Question 45

how and when will you check the binocular status of your lv px when determining they refractive correction

Answer 45

- by doing CT or EOM if required | - only check if px has diplopia or you see a squint, as VI px will usually have one very bad eye

Question 46

what must you remember to take into account when prescribing

Answer 46

the working distance used for subjective acceptance. it is important if the px's working distance is 3m or less

Question 47

what must be in place in order to determine near acuity on your lv px

Answer 47

distance correction and appropriate addition

Question 48

what add should you always check with for what a px can read when determining a lv px's near vision and at what distance should this be

Answer 48

+4.00D add at 25cm

Question 49

what type of near chart us best to use on your lv px when checking their near acuity and why

Answer 49

a word chart | because the px can guess the next word in the sentence and this is not a good estimation of near va

Question 50

as well as near acuity, what else must you record when measuring near vision

Answer 50

record what type of illumination was preferred

Question 51

name 2 additional tests you can carry out after determining the refractive error of your lv px

Answer 51

- visual field test: area of distortion/defect | - contrast sensitivity: if you feel theres a need to that

Question 52

which three things can you use to measure visual fields on your lv px

Answer 52

- amsler grid: for central vf - arc perimeter - tangent screen

Question 53

what 2 things do 10-20% of lv patients only need

Answer 53

a good refraction and advice on lighting so don't need a full lv examination

Question 54

what is required in va of an lv px to appreciate subjective improvement

Answer 54

an increase of at least 2 lines | so only change glasses if theres that much of an difference

Question 55

what may not all lv px's benefit with

Answer 55

an LVA | they may need sensory substitution e.g. braille or convert text to speech

Question 56

what must you need to determine when prescribing magnification

Answer 56

whether monocular or binocular correction would be preferable

Question 57

how is magnification for distance calculated

Answer 57

mag = required va/present va e.g. required va = 6/6 (to watch tv) present va = 6/18 mag = (6/6) / (6/18) = 3x.....18/6 = 3x (dist lv aid)

Question 58

how is magnification for distance calculated using a LogMAR chart

Answer 58

``` magnification = (1.25)n n = number of steps e.g. required va = 0.1 present va = 0.5 ``` mag required = (1.25)4 = 2.5x n = 4 steps

Question 59

what is the rule of thumb when predicting near magnification from distance vision

Answer 59

always divide by 3 e.g. if distance va = 6/18 then near va = 18/3 = N6 but it is better not to predict near vision from distance vision

Question 60

what are three disadvantages to predicting near magnification from distance va

Answer 60

- crowding effects with words (as with distance va you're measuring isolated letters on a chart) - increased va with sentences (can guess whats coming up next) - cataracts (e.g. nuclear sclerosis makes px more myopic, bad dv but good nv, so can't use the divided by 3 rule)

Question 61

at what distance should you measure patients current near va

Answer 61

25cm

Question 62

how do you use the LogMAR chart to measure a patients near magnification

Answer 62

same as for distance mag ``` magnification = (1.25)n n = number of steps e.g. required va = 0.1 present va = 0.5 at 25cm ``` mag required = (1.25)4 = 2.5x n = 4 steps

Question 63

how do you use N notation to measure a patients near magnification

Answer 63

magnification = present va/required va present va = N16 @ 25cm required va = N8 @ 25cm magnification = 16/8 = 2x

Question 64

what are the 2 ways to calculate near magnification

Answer 64

- LogMAR chart | - N notation

Question 65

what will a lv px require for each task that they wish to perform

Answer 65

a separate lv aid

Question 66

what will a lv patients ability to read for leisure depend on

Answer 66

their acuity and contrast reserve

Question 67

what type of magnifier is available for distance tasks

Answer 67

telescope: monocular or binocular

Question 68

what 4 types of magnifiers are available for near tasks

Answer 68

- spectacle mounted magnifier - hand magnifier - stand magnifier - near vision telescope

Question 69

when trialling a predicted magnification, what should you assess

Answer 69

the patients visual acuity with the selected aid

Question 70

what should you increase or decrease the magnification go the aid depending on

Answer 70

the acuity achieved and task requirement always give minimal magnification that gives you best acuity

Question 71

which rx does a distance telescope need to be used with

Answer 71

distance rx

Question 72

which rx does a hand magnifier need to be used with and why

Answer 72

distance rx | as the rays of light leaving the HM are parallel so the patient does not accommodate when using this aid

Question 73

which rx does a stand magnifier need to be used with and why

Answer 73

near rx as the rays of light diverge, the px needs the rays of light to converge, whereas older patients can't accommodate so they need a near rx

Question 74

what can you do with a lv aid if its under the nhs

Answer 74

loan the aid for home trial

Question 75

what must you mention when explaining to the patient how to use the lv aid

Answer 75

- which rx the aid should be used with | - how to clean the aid and charge the batteries if required

Question 76

what is the next step after dispensing a lv aid

Answer 76

a follow up visit

Question 77

after how long is a follow up visit after dispensing a lv aid

Answer 77

usually 3 weeks (to check that they know how to use the LVA)

Question 78

after the first 3 weeks visit of dispensing a lv aid, how often should subsequent visits be

Answer 78

either yearly or whenever the patient experiences difficulties

Question 79

name 3 reasons why an lv aid may not be successful at a follow up visit

Answer 79

- deterioration in va 9 (e.g. wet AMD) - aid is used incorrectly e.g. too far away from the eye or inappropriate lighting - using the aid for a different task than what is was intended for

Question 80

what should you do with the LVA if it isn't successful due to deterioration in va

Answer 80

select a different possible stronger aid

Question 81

what should you do with the LVA if it isn't successful due to the aid being used incorrectly

Answer 81

give appropriate training/advice

Question 82

what should you do with the LVA if it isn't successful due to using the aid for a different task than what it was intended for

Answer 82

explain the intended use of the aid

Question 83

what 4 final things should you do upon completing the lv assessment visit

Answer 83

- give patient the contact details of the practice and encourage the patient to call if a problem arises - encourage the patient to implement practical tips that were suggested e.g. the use of felt tip pens etc - give the px useful contacts such as: RNIB, macular degeneration society, social services department - report to the: GP/optometrist/ophthalmologist where appropriate