Investigation and management of anomalies of convergence and accommodation Flashcards
1
Q
list the 4 classifications of convergence anomalies
A
- Convergence insufficiency
- Convergence fatigue
- Convergence paralysis
- Convergence accommodative / spasm
2
Q
what is a convergence insufficiency
A
inability to obtain adequate binocular convergence without undue effort
can’t converge the eyes binocularly but can converge eventually but with a lot of effort
3
Q
what is convergence fatigue
A
inability to maintain convergence over time
can converge the eyes binocularly to begin with but over time this fatigues and you can do it
4
Q
which classification of convergence anomaly is relatively common
A
convergence insufficiency
5
Q
what are the 2 types of convergence insufficiency
A
- primary
or - secondary
6
Q
convergence insufficiency is easily….
A
treatable
7
Q
what is meant by a primary convergence insufficiency
A
the first ocular thing that happens is the convergence insufficiency
8
Q
what is meant my secondary convergence insufficiency
A
something else happened before the CI. which then caused the CI
9
Q
list 8 precipitating factors of a primary convergence insufficiency
A
- Illness
- Fatigue
- Drugs: Antidepressants/Cocaine
- Pregnancy
- Students with a lot of exam stress
- Change of jobs/lifestyle
- Computers
- Constant distance vision
10
Q
list 7 things that a secondary convergence insufficiency can be due to
A
- Heterophoria - uncorrected exophoria
- Uncorrected refractive errors
- Accommodative insufficiency
- Iatrogenic weakened medial recti
- Parkinson’s
- Thyroid eye disease
- Inter nuclear ophthalmoplegia
11
Q
what do you need to do in order to find out if a convergence insufficiency is primary or secondary
A
you need to conduct a good BV exam
12
Q
list 7 symptoms of convergence insufficiency and fatigue (i.e. when trying to converge but can’t)
A
- Headaches
- Eyestrain
- Difficulty changing focus
- Asthenopia
- Blurred vision (XOP decomp.) - if dipl is very close together
- Diplopia (XOT) - if fail to converge
- Convergence fatigue - symptoms occur after prolonged near work (so no symptoms initially)
13
Q
when do the symptoms of convergence fatigue occur
A
after prolonged near work
14
Q
list all 11 tests that can be conducted to investigate a convergence insufficiency and fatigue
A
- cover test
- convergence, near point with RAF rule
- jump convergence
- prism fusion range
- accommodation
others that can be done:
- Measure deviation with prism cover test
- Visual acuity
- Stereoacuity
- Ocular motility
- Fundus examination
- Cycloplegic refraction in children
15
Q
what can a cover test reveal about a convergence insufficiency
A
- XOP /XOT at near
- Orthophoria distance - as eyes don’t need to converge
16
Q
what can a cover test reveal about a convergence fatigue
A
XOP /XOT at near after prolonged dissociation
so no problems initially
17
Q
what will a convergence near point test with a RAF rule reveal about a convergence insufficiency and what is the advantage of using a RAF rule
A
will have a reduced or poorly maintained near point
this is done to get a precise measurement
18
Q
why is it good practice to measure near point with the RAF rule 3 times
A
- to get a precise measurement for CI
- for CF it will be revealed on the 2nd or 3rd time and not the 1st (which will show as normal)
19
Q
what will a convergence near point test with a RAF rule reveal about a convergence fatigue
A
on 2nd/3rd attempt NP reduces
20
Q
which 2 ways can you test convergence near point with the RAF rule
A
- subjectively
and/or - objectively
21
Q
how is convergence near point with the RAF rule tested subjectively, and what do you need to keep in mind
A
- When patient reports diplopia
- Remember that the target will be blurred (test does NOT examine accommodation)
22
Q
how is convergence near point with the RAF rule tested objectively and give an example of how the results will be written down for a convergence fatigue
A
- Watch the patients eyes for convergence to break:
Note the eye which diverges first
Note the distance and whether they were able to maintain convergence
Note whether diplopia was noticed
Conv: binoc to 10,15,20 cms re diverged with diplopia
23
Q
describe how a jump convergence is carried out when testing for convergence insufficiency or fatigue and what the results will be like for someone with a convergence insufficiency
A
- Hold two objects in front of the patient (ask px to look at further away object)
- One object held closer to their face than the other
- Request the patient to look from the distance object to the near object each time bringing the near object closer
- Reduced in CI
24
Q
which other convergence test is jump test harder to do than
A
near point with RAF
25
in which type of patients in particular is prism fusion range carried out in and why when measuring convergence insufficiency
- children
- as they can make answers up
- a child is able to make their eye drift out when measuring with the RAF rule
26
what will the results in a prism fusion range test show in a child with convergence insufficiency
Base Out (cOnvergence) at near = reduced in CI
27
what will the results in a prism fusion range test show in a child with convergence fatigue
base out at near reduces on prolonged testing
28
why is accommodation tested when investigating convergence insufficiency/fatigue
because it is part of the near triad:
- convergence
- accommodation
- pupil miosis
so they're all inter-linked as with a CI you also get a accommodative insufficiency with it.
so if a px has a convergence problem, always check accommodation with it
29
describe how accommodation is measured when investigating convergence insufficiency
- Near point assessed with RAF rule in dioptres
- Assessed three times (insufficiency versus fatigue)
- Need to know normal level for their age
- Assessed monocularly and binocularly (differential diagnosis CI or AI)
30
how can you tell that a px has a problem with convergence and not accommodation when measuring accommodation with the RAF rule
- Assessed monocularly and binocularly
- if binocular accommodation is reduced, but when you check monocularly and accommodation is perfectly normal for their age, then this is a convergence problem
31
what is the outcome/results of measuring the deviation with a prism cover test with a CI patient
- XOP/XOT usually at near
- Orthophoria at distance
if the exophoria is getting bigger and bigger = convergence insufficiency is getting worse
32
what is a reduced visual acuity associated with, when investigating convergence insufficiency
- Reduced if associated with AI
- measured at distance and near
- if reduced at near = accommodation problem
33
what is the outcome/results of measuring stereo acuity on a CI patient
- Might be reduced or absent
| - if CI gets worse and exophoria becomes exotropia = steer acuity can get worse
34
what is the outcome/results of measuring ocular motility on a CI patient
- If incomitant refer (TED, INO)
- as a secondary CI can be caused by thread eye disease or INO, so make sure nothing else is the cause apart from the CI itself
35
what are the 3 main steps with management of convergence insufficiency
- Treat any pathology
- Significant refractive error corrected - give glasses
- Exercises - to most CI px's
36
what is the first line of treatment for convergence insufficiency and give 5 examples
orthoptic exercises:
- dot card
- convergence
- jump convergence
- base out fusion range at near
- voluntary convergence
- stereogram/positive relative convergence
37
list the steps of how to do an orthoptic exercise using the dot card
- Card length 30 cms.
- Place the card at the end of the nose
- The line will appear double (phys dip)
- Need to keep each dot as single
- Start with the dot furthest away and come closer whilst keeping the dot single
- want px to manage to look at the closest dot and keep it single
38
describe how convergence exercise is carried out for a patient with a CI
- Binocular convergence with a pen
- Using Lollipop stick with letters
- for a presbyope, the letter will not be clear, but just want them to keep it single
39
how will a patient be able to do base out prism fusion range at near to exercise their CI
by us lending them a prism bar
40
describe how the stereogram is carried out as an exercise for CI
- 2 similar pictures with some differing characteristics
- Patient requested to hold the card at approx. 33cms
- The patient then stares at a near object (pencil) in front of the card. They must not look at the card itself to begin with
- The position of the target is then changed until 3 figures are seen
= positive relative convergence
41
list 6 points to take into consideration about orthoptic exercises for CI in general
- Watch each patient carrying out their exercises (to make sure they do it properly)
- Symptoms may initially worsen e.g. headaches, eye strain
- Lots of encouragement
- Specify how much time
- Must relax eyes afterwards:
By looking far away or closing eyes
To reduce risk of convergence spasm
- Should be regularly monitored
42
give an example of why a person who is doing orthoptic exercises for their CI should be regularly monitored
because occasionally, the patient can do so many exercises that their convergence spasms i.e. goes to the opposite way meaning they have an over convergence and an esophoria
43
what other treatment will you do for a CI if occasionally the exercises doesn't work and name the type of this treatment
- surgery
| - Von Noorden (1976) consider M-R resections with large angled deviations (VERY,VERY RARE)
44
how will you go about treating a secondary CI
by addressing the primary condition first
45
what is a convergence paralysis
The ability to converge closer than infinity is entirely lost
i.e. no convergence what so ever
46
what are the 2 types of convergence paralysis
- primary
or
- secondary
47
list 4 possible causes of secondary convergence paralysis and what must you do with these patients
- Closed head injury
- Viral illness
- Occlusive vascular disease
- Encephalitis feature of Parinaud’s
must refer the last 2 patients urgently, always refer someone with a convergence paralysis
48
list the 6 signs and symptoms of convergence paralysis
- At distances closer than infinity:
Nil convergence
XOT
Crossed diplopia
- Accommodation may be normal reduced or absent at distances closer than infinity
Blurred near v-a if accommodation effected
- Pupillary response maybe absent for convergence
present for light
- Normal ocular movements
unless associated with another neurological condition
- Examined in exactly the same way as CI
- Absent positive fusion range
good negative fusion range
49
what type of signs and symptoms will a patient with convergence paralysis have at distances closer than infinity
Nil convergence
XOT
Crossed diplopia
50
how will a patients accommodation be and symptoms with convergence paralysis
Accommodation may be normal reduced or absent at distances closer than infinity
Blurred near v-a if accommodation effected
51
what will a patient with convergence paralysis pupillary response be like
maybe absent for convergence
| present for light
52
what will a patient with convergence paralysis ocular movements be like
Normal ocular movements
| unless associated with another neurological condition
53
what will a patient with convergence paralysis fusion range be like
Absent positive fusion range
| good negative fusion range
54
list the 6 management steps/options of convergence paralysis
```
- Urgent referral: dont try to treat yourself
Underlying cause investigated
Fundus examination (pathology treated accordingly)
```
- Occlusion: to stop diplopia, can occlude specs or use occlusive CL
- Botulinum Toxin (BT)
- Base in prisms to correct XOT: to also stop diplopia
- If also has AI then near reading addition: treat with convex lenses
- Adapt to symptoms
55
what else does a spasm of convergence also cause and what does this make difficult
- spasm of accommodation and miosis
| - therefore unable to determine which was the primary cause
56
what happens in the eye as a result of a convergence spasm
MR may become contracted
57
what happens in the eye as a result of accommodative spasm
Ciliary muscle becomes contracted
58
list 5 possible aetiologies of convergence/accommodative spasm
- Over zealous treatment of CI: too much exercise
- Uncorrected hypermetropia: try to focus their eyes themselves, in doing that it locks in
- Intermittent distance XOT
- Organic:
Drugs/ Inflammation/ alcohol
Problem within the brain: lesions caused by strokes or multiple sclerosis, so must treat these px very carefully
- Non organic:
Psychological: main cause and mainly in women
59
list 8 signs and symptoms of convergence/accommodative spasm
- Could result in a SOT
(uncrossed diplopia)
- SOT >distance and lateral positions of gaze
- Blurred vision in the distance - accommodative spasm
- Macropsia - image size is bigger than is naturally is
- Constricted pupils
- Pseudomyopia
- Headache
- Lead on dynamic retinoscopy
60
explain what pseudo myopia is (caused as a result of convergence/accommodative spasm)
when someone is really accommodating a lot, it illustrates a pseudo myopic eye as the rays of light will fall infront of the retina
dry ret and auto refractor will show myopia and then after a cylcoplegic refraction, they can show as hyperopic
61
what is the differential diagnosis of a convergence/accommodative spasm and list 3 signs that differentiate this from a convergence/accommodative spasm
- Sixth nerve palsy:
Pupils normal
Dolls head abnormal
V-A normal
if a px has an esotropia that is greater in the distance, then that could be a 6th nerve palsy
62
explain how a normal dolls head works which is present in a accommodative/convergence spasm but not in a 6th nerve palsy which it is found to be abnormal
normal = each eye will fully abduct
63
list 8 things that you can do to manage a convergence/accommodative spasm
- Pathology treated accordingly
- Cycloplegic or even better atropine refraction to elicit full hypermetropic Rx
- ANY hypermetropic refractive error corrected
- Daily atropine instillation (with convex lenses to help near work)
- Monocular occlusion
- Botulinum toxin
- Psychiatric counselling
- Treatment should include improving their negative fusion amplitude
this spasm can happen in different distributions e.g. a little bit of convergence spasm and a lot of accommodative spasm. so need to manage appropriately to the level of spasm that they got
64
list the 3 classifications/types of accommodative disorders
- Accommodative insufficiency
- Accommodative paralysis
- Accommodative inertia
65
list the 5 possible aetiologies of accommodative insufficiency/fatigue
- High hyperopia
- Children with Down’s syndrome
- Illness: Infection or glandular fever
- Drugs: antihypertensive, antidepressants
- Trauma
66
list the 6 types of symptoms of a accommodative insufficiency and fatigue
- Burred vision at near
- Remote NP accommodation
- Asthenopia
- Micropsia: image is smaller than what is naturally is
- Associated with CI
- Occasionally SOP because effort to accommodate, it pulls their eyes in
If accommodative fatigue - then above symptoms occur after prolonged near work
67
list three tests that can be done to investigate accommodative insufficiency/fatigue
- near point of amplitude - subjective
- dynamic retinoscopy - MEM or Nott method
- flipper lenses
68
describe how will you investigate someones accommodative insufficiency/fatigue from their near point of amplitude
- Using RAF rule with small print
- Carry out monocularly and binocularly
- Adjust for age
69
describe how will assess someones accommodative insufficiency/fatigue with flipper lenses
- pairs of plus and minus lenses
+/-1.00
+/-1.50
+/-2.00
- View a near target through plus lenses
- When vision clears flip to the minus lenses
- Count how many cycles you can clear in a minute
- 1 cycle is one rotation from plus to minus to plus again
10 cycles of +/-2.00 is normal for a young adult
Like amplitude varies with age
70
what is regarded as normal accommodative facility for a young adult
10 cycles of +/-2.00
71
list 4 signs of accommodative insufficiency, revealed from the various tests used to assess it
- XOP or SOP at near (because of effort to accommodate)
xop = if given up trying to accommodate
esop = if really trying to accommodate
- Reduced NP accommodation for age
- Dynamic retinoscopy (shows a lag)
- Accommodative facility might be reduced: less than 8-10 cycles per minute
72
list 5 clinical sins of accommodative fatigue
- Unable to maintain NP of accommodation x 3
- Reduced accommodative facility
- Dynamic retinoscopy normal to begin with, then developing a lag (usually have to be quick, but won't see the fatigue like this so need to do it slowly in this case)
- Distance vision normal, near vision initially normal but then reduces over time
- CT reveals SOP for near over time
73
list 6 possible things you can do for the management of an AI/fatigue
- Fundus examination (pathology treated)
- Cycloplegic refraction
- Correct refractive error particularly hypermetropia
- Extra convex lenses for reading (CRUTCH, so will only stop symptoms, but not get any better)
- Exercises - will make the accommodation better
- Down’s syndrome
- Bifocal’s for short period
74
list 2 types of exercises you can give a patient with accommodative insufficiency/fatigue to do and describe how each one is done
- Lend Flippers
+/-1.00,+/-1.50 +/-2.00
Try to increase number of rotations they can clear/minute and do it several times a day
- Accommodative push ups
With letters on lollipop stick, ask ox to bring towards their nose and ask to try and keep the letters clear and sharp
Done for 1-2 minutes
Monocularly and binocularly
75
list 5 possible aetiologies of accommodative paralysis
- Maybe associated with convergence paralysis
- Drugs (cycloplegia may accidentally be introduced
into the conjunctival sac)
- Psychosomatic
- Neurological
Diptheria
Parinauds
Total 3rd nerve palsy
- Trauma
Blunt causing paralysis of the ciliary muscle
Closed head injuries
Whiplash
76
list 3 neurological causes of a accommodative paralysis
- Diphtheria
- Parinauds
- Total 3rd nerve palsy
77
list 3 traumatic causes of a accommodative paralysis
- Blunt causing paralysis of the ciliary muscle
- Closed head injuries
- Whiplash
78
list 5 signs and symptoms of accommodative paralysis
- No accommodation can be exerted
- Accommodative facility not possible
- Large lag with dynamic retinoscopy
- Burred visual acuity for distances closer than infinity
- Occurs monocularly and binocularly
79
list 6 possible things that can be done for the management of accommodative paralysis
- Refer urgently if recent onset to ophthalmologist
- Fundus examination (pathology treated)
- Aetiology identified and treated
- Refraction in children, but NOT cyclopegic
- Correct any hypermetropia or astigmatic error
- In unilateral paralysis attempt to match the near points of the two eyes by use of multifocal reading addition
80
how will you manage a unilateral accommodative paralysis
attempt to match the near points of the two eyes by use of multifocal reading addition
81
list 3 points that describe accommodative inertia
- Difficulty changing focus
- Difficulty relaxing and exerting accommodation
- Occurs in both eyes
82
name 2 possible aetiologies with accommodative inertia
- Associated with presbyopia
- Developing cataract
i.e. elderly patients may mainly complain of this
83
list 3 signs and symptoms of accommodative inertia
- Complains of burred vision when changing from near to distance
- Distance and near vision: both may be reduced until significant time has passed
- Take lots of time to investigate near point of accommodation
84
list 4 things that can be done for the management of accommodative inertia
- Fundus examination (pathology treated accordingly)
- Correct even minimal hypermetropic correction
- Bifocal reading addition of +1.OO DS may help
- Orthoptic exercises
Accommodative flippers
Improve near point of accommodation (push up accommodation)
Jump accommodation (like jump convergence but keeping letter clear)
85
list 3 types of orthoptic exercises given to patients with accommodative inertia
- Accommodative flippers
- Improve near point of accommodation (push up accommodation)
- Jump accommodation (like jump convergence but keeping letter clear)
86
which is the best orthoptic exercise for accommodative inertia and why
- accommodative flippers
| - as it will strengthen both their accommodation and their relaxation
87
what is a advantage and a disadvantage of giving a exercise for accommodative inertia to improve near point of accommodation (push up accommodation)
- advantage: will strengthen their accommodation
| - disadvantage: but won't strengthen/improve their relaxation
88
Which investigation would use in a child where the subjective responses were unreliable?
- RAF rule
- Dynamic retinoscopy
- Flipper lenses
- Cover test
Dynamic retinoscopy
