Lecture 5 Anomalies of convergence and Accommodation Flashcards
What convergence anomalies can you get?
convergence insufficiency
convergence fatigue
convergence paralysis
covergence/accommodative spasm
What is convergence insufficiency?
what is normal amount?
Inability to obtain binocular convergence without undue effort
primary and secondary
common abnormality
6-10cm
What are the precipitating factors of primary convergence insufficiency?
illness
fatigue
drugs (antidepressants)
pregnancy
students with exam stress
change of jobs (using one eye)
computers
constant distance vision
What are the causes of secondary convergence insufficiency?
Heterphoria-converge weakness phoria
uncorrected refractive errors-not wearing glasses
Accommodative insufficiency
latrogenic weakened medial recti-surgeon can cause CI
parkinsons
thyroid eye disease
internuclear ophthalmoplegia
What are the causes of secondary convergence insufficiency?
Heterphoria-converge weakness phoria
uncorrected refractive errors-not wearing glasses
Accommodative insufficiency
latrogenic weakened medial recti-surgeon can cause CI
parkinsons- refer to GP
thyroid eye disease- refer to GP and HES
internuclear ophthalmoplegia- refer HES
What are the symptoms of convergence insufficiency?
headaches
eyestrain
difficulty changing focus
asthenopia
blurred vision (XOP decompensating)
Diplopia (XOT)
What cover test results will you get in the distance for someone who has convergence insufficiency?
Don’t need to converge in the distance a
px will be orthophoric in distant
What cover test results will you get at near for someone who has convergence insufficiency?
failure to converge at near
exophoria
exotropia if severe CI and more constant
CR will be nasally displaced
What is convergence fatigue?
*Initially able to converge properly
*Over prolonged period, convergence decreases
*Symptoms occur after prolonged near work
What cover test results are you likely to get in a px with convergence fatigue?
*Initially cover test will be normal for distance and near
*After prolonged dissociation with occluder, it may start to reveal exophoria or exotropia at NEAR.
What differences can you expect between convergence insufficiency and convergence fatigue when measuring them using an RAF rule?
CI-reduced or poorly mantained near point
CF-first attempt normal, 2/3rd attempt near point reduces
How do you measure NPC?
Test subjectively- when px reports diplopia
Test objectively- note which eye diverges first
Make sure they are wearing glasses (presbyopes SVN, hyperopes, and high myopes).
What is Jump covergence?
*Ask them to look at a distance object and then the near object
*Px looks at the green distance star and then the near red star. Each time we come back to the near object, move the red star closer to the eyes.
*Each time they look to the near object, they will be converging more and more.
What else should you measure if convergence is impaired?
accommodation
PCT
VA
stereo acuity
ocular motility
fundus exam
cycloplegic refraction
PFR- BO at near is reduced
What is the management of convergence insufficiency?
treat underlying pathology
full refractive error corrected
exercises
What exercises can you have for convergence issues?
DOT CARD- place card at the end of nose and try to keep furthest dot single.
Binocular convergence exercise with pen
Jump convergence exercises
Lend prism bar for BO
Stereogram- done at 33cm, 2 targets with some different characteristics. px stares at near object in front (pen) and moves the target until 3 figures seen.
What are the rules about giving convergence exercises?
watch px carry out exercises
symptoms may initially worsen
give a lot of encouragement
specify how long they should do them for (1-2 mins x3 daily)
MUST relax eyes afterwards by looking at objects far away to reduce risk of convergence spasm
regular monitor these px due to risk of convergence spasm
give px written instructions for exercises
tell px if you carry out exercise regularly, they will work
What is convergence paralysis?
*The ability to converge closer than infinity is entirely lost
What is the etiology of convergence paralysis?
primary or secondary
secondary: closed head injury, viral illness, occlusive vascular disease, encephalitis feature of Parinauds
What are the symptoms and signs of convergence paralysis?
-XOT with crossed diplopia
*No response to pupil constriction when eyes converge. Pupils will converge when light shone in them.
*Blurred near vision as accommodation effected
*Normal ocular movements (unless associated with neurological condition)
*Nil BO fusional reserves
*Good BI fusional reserves
What is the Management of convergence paralysis?
URGENT referral
occlusion
Botulinum toxin
BI prisms to correct XOT
if they also have accommodative insufficiency, give near ADD
What is convergence/accommodative spasm?
*We don’t know if convergence spasmed first or accommodation spasmed first
*If you get convergence and spasm accommodation spasm, you will also get pupil miosis.
*Convergence spasm: MR may become contracted
*Accommodative spasm: ciliary muscles become contracted
What is the Aetiology of convergence/accommodative spasm?
*Overzealous treatment of CI (exercising too much)
*Uncorrected hyperopia: accommodation resulting in convergence
*Intermittent distance XOT: trying to accommodate and pulling your eyes in to converge
*Organic: drugs, inflammation, alcohol. Problems with brain.
*Non organic: psychological
What are the signs and symptoms of convergence/accommodative spasm?
*Could result in esotropia (uncrossed double vision)
*Esotropia greatest in distance (as you need to relax convergence the most)
*MR are getting tighter due to convergence spasm. So, if you look to the side, esotropia will increase as MR can’t relax
*Blurred vision in the distance
*Macropsia
*Constricted pupil
*Pseudo myopia (accommodating so hard so rays fall Infront of retina)
*Headache
*Lead on dynamic ret (accommodated too much)
What is the dd of convergence/accommodative spasm?
6th nerve palsy
if you find LR weakness, refer
What is the management of convergence/accommodative spasm?
*Treat pathology first
*Cycloplegic or atropine refraction to give full hypermetropic rx
*Correct any hypermetropic error as it relaxes accommodation
*Can give extras plus at near or instil atropine to relax accommodation
*Monocular occlusion- relieve spasm
*Botulinum toxin
*Psychiatric counselling if cause of spasm was phycological.
*Improving BO fusion amplitude
What is the management of convergence/accommodative spasm?
*Treat pathology first
*Cycloplegic or atropine refraction to give full hypermetropic rx
*Correct any hypermetropic error as it relaxes accommodation
*Can give extras plus at near or instil atropine to relax accommodation
*Monocular occlusion- relieve spasm
*Botulinum toxin
*Psychiatric counseling if cause of spasm was phycological.
*Improving BO fusion amplitude
What accommodative disorders can you get?
- accommodative insufficiency/fatigue
- accommodative paralysis
- accommodative inertia
What is the aetiology of accommodative insufficiency/fatigue?
-high hyperopia
-children with Downs
-illness
-drugs (antihypertensive, antidepressants)
-Trauma
What are the symptoms/signs of accommodative insufficiency/fatigue?
- Blurred vision at near
- Asthenopia
- Micropsia
- Remote NP accommodation
- Associated CI
- Occasional sop -px is trying to accommodate so hard it pulls their eyes in
- Accommodative fatigue
What tests can you do to investigate accommodation issues?
AoA
NPC
dynamic ret
accommodative facility
CT
What are the signs of accommodative fatigue?
*Unable to maintain NP of accommodation3x
*Reduced accommodative facility
*Dynamic ret normal to begin with then lag develops
*Distance vison normal, near vison initially normal but then reduces over time
*CT shows SOP near over time
What are the signs of accommodative insufficiency?
*XOP or SOP at near because of effort to accommodate
*Reduced NP of accommodation for their age
*Dynamic ret:lag
*Accommodative facility: reduced amount of cycles
How do you carry out accommodative facility?
flipper lenses +/-2.00 DS flippers
px views N5 first through plus lenses then minus lenses
px shouts clear when text is clear through the lenses
count how many cycles px can clear in a minute.
normal amount for a young adult: 9-11
What is the management for accommodative insufficiency/fatigue?
*Fundus examination (pathology treated first)
*Cycloplegic refraction
*Correct ALL hypermetropia
*Extra convex lens for reading (just stopping symptoms, not treating)
*Exercises
*Down syndrome: bifocals for a short period of time stimulates accommodation
What exercises can you give to treat accommodative insufficiency/fatigue?
flipper lenses- suggest 1-2 mins x3 daily
accommodative push-ups-with letters on a lollipop stick, keep letters clear as you get closer to nose.
What is the aetiology of accommodative paralysis?
*Association with convergence paralysis
*Drugs (cycloplegia may accidently be introduced into conjunctival sac
*Psychosomatic
*Neurological (diphtheria, Paronnaud’s, total 3rd nerve palsy)
*Trauma (blunt causing paralysis of ciliary muscle, closed head injuries, whiplash).
What are the signs and symptoms of accommodative paralysis?
no accommodation
accommodative facility is not possible
dynamic ret=no accommodation
blurred VA for distances closer than infinity
occurs monocularly and binocularly
What is the management of accommodative paralysis?
refer urgently if recent onset
fundus exam
refraction in children
correct any hypertropia or astigmatic error
unilateral paralysis: attempt to match near points of both eyes by using reading ADD
What is accommodative inertia?
*Difficulty changing focus (when they look from distance to near it becomes blurred and eventually clears at near. When they look in the distance its blurry then eventually clears)
*Difficulty relaxing and exerting accommodation
*Occurs in both eyes
What is the etiology of accommodative inertia?
what are the symptoms?
what is the management?
-presbyopia
-developing cataract
-Blurred vision when changing from distance to near
-Reduced distance and near vision until significant time has passed
-Takes a lot of time to investigate near point of accommodation
*Fundus exam (pathology treated first)
*Correct even minimal hypermetropic correction
*Bifocal reading add of +1.00 may help
*Orthoptic exercises (accommodative flippers, push up accommodation, jump accommodation)
