5. Investigation and management of convergence and accommodation anomalies

what makes the near triad

convergence
accomodation
pupil miosis

what are the primary causes of convergence insufficiency CI

illness
fatigue
drugs
antidepressants
pregnancy

what are the secondary causes of convergence insufficiency CI

heterophoria
presbyopia
uncorrected rx
accom insufficiency
thyroid eye disease

what are the symptoms of convergence insufficiency CI

headaches
eyestrain
sore eyes
difficulty changing focus
blurred vision caused by XOP breaking down

how would you test convergence insufficiency

NPC
jump convergence
CT- decompensated xop may be present

fusional reserves
convegent FR may be low

VA- low VA at near

stereoacuity- may be low

ocular motility

what are normal NPC values

should be 8cm
ideally 5cm

what is convergence paralysis

The ability to converge closer than infinity is entirely lost

In convergence paresis some ability to converge is retained

what are the causes of convergence paralysis

closed head injury, viral illness, occlusive vascular disease, multiple
sclerosis, encephalitis

what are the symptoms of convergence paralysis

diplopia and blurred vision at distances closer than infinity

what are the signs of convergence paralysis

• XOT at distances closer than infinity
• Accommodation may be normal, reduced or absent
• Pupillary response may be absent for convergence and present for light
• Normal ocular movements
• Absent positive fusion range good negative fusion range
• Examined in exactly same was as CI (NPC, jump convergence, CT)

what is accomodative insufficiency

Inability to obtain or maintain adequate accommodation for comfortable
binocular vision at near

what are the causes of accom insuffieincy

High hypermetropia, illness, drugs, trauma, infection, prolonged fever

what are the symptoms of AI

Blurred vision at near, asthenopia, micropsia

what is accomodative fatigue

Inability to sustain adequate accommodation over time. It is usually due to
repeated or sustained visual effort

what are the causes of accom fat

poor general health, fatigue, psychological, drugs

what are the symptoms of accom fat

Near vision is initially normal, but then reduces over time

may be a near SOP

what is accomodative infacility (inertia)

Inability to adequately change accommodation

what are the causes of accomodative infacility

accommodative spasm, uncorrected hypermetropia, presbyopia,
excessive amounts of close work at too close working distance

what are the symptoms of accomodative infacility

blurred vision when changing fixation from near to distance or
distance to near, both distance and/or near vision may be reduced

what is accomodative paralysis

The ability to accommodate to near objects is entirely lost. No accommodation can be exerted

what are the causes of accomdative paralysis

convergence paralysis
neurological (3rd. nerve pasly, Parinaud's syndrome)
trauma

what are the symptoms of accomodative paralysis

blurred vision for distances closer than infinity

what is convergence/accomodative spasm

Spasm of convergence usually causes spasm of accommodation and miosis

what becomes contracted in convergence (1) and accomodative spasm (2)

1- medial rectus
2- cilary muscle

what are the causes of spasm

uncorrected hypermetropia, intermittent distance XOT, drugs/alcohol,
inflammation, very often of psychogenic origin, trauma, neurologic
(encephalitis, lesion in CNS)

what are the symptoms of spasm

blurred vision, intermittent diplopia, headache, asthenopia

how to use the RAF rule to diagnose what

near point of accom
RAF rule
assessed 3 times to help diagnosing AI and accom fatigue
assessed monocularly and binoculalry to help diagnosing AI and CI

how would you use accom facility test and what does it measure

measures rate of change of accommodation

done binocularly and monocularly

measure cycle per minute (8 is normal)

how would you use accom accuracy to diagnose accomodation anomolies

objetcive test
accom lag measured using dynamic ret (MEM or Nott)

how to manage CI

Treat any pathology

correct any refractive error

cycloplegic refraction should be conducted when appropriate

CI nearly always be treated successfully using orthoptic exercises

secondary CI need to address the primary condition so refer if ocular diseases detected

anti suppression tests

bar reading

dot card

stereograms

base out prism

describe the 2 orthoptic exercises to manage CI

pencil-to-nose
-Patient is asked to look at a pencil at 50cm and maintain single and clear vision while the pen is moved towards the patient's eyes
- Patient reports when the pencil is double and stops
- Try and bring convergence closer by repeating exercise

near-far jump
-Fixation 'jumps' between near and distance targets
-- Prior to 'jumping' to other distance patient should see target clear and single
- The patient should ensure that he/she sees the object clear and single before 'jumping' to the other distance

how would you manage convergence paralysis

-Pathology (if any) treat and/or refer for treatment accordingly
• If early onset refer for ophthalmological examination
• Botulinum toxin
• Occlusion
• Base in prisms
• Surgery

how would you manage accom insufficiency

• Pathology (if any) treat or/or refer for treatment accordingly
• Correct refractive error, particularly hypermetropia (consider cycloplegic
refraction, if appropriate)
• SV for reading, progressive or bifocal
• If patient is not keen on glasses try orthoptic exercises

what 2 tests for managing AI

accom push up

lens flippers

how to manage accomodative fatigue

• Pathology (if any) treat or/or refer for treatment accordingly
• Correct refractive error, particularly hypermetropia (consider cycloplegic
refraction, if appropriate)
• Orthoptic exercises (same as AI)
- Accommodative push-ups
- Lens flippers

how would you manage accom infacility

• Pathology (if any) treat or/or refer for treatment accordingly
• Correct refractive error, particularly hypermetropia (consider cycloplegic
refraction, if appropriate)
• Bifocal for reading with a low add (+1.00) may help
• Orthoptic exercises
- Accommodative push-ups
- Lens flippers
- Near-far jump exercises (ensure patient keeps letters single and
clear)

how would you manage accom paralysis

• Pathology (if any) treat or/or refer for treatment accordingly• Correct refractive error, particularly hypermetropia (consider cycloplegicrefraction, if appropriate)• SV for reading, progressive or bifocal

how would you manage convergence/accom spasm

• Pathology (if any) treat or/or refer for treatment accordingly
• Correct refractive error, particularly hypermetropia (consider cycloplegic
refraction, if appropriate)
• Short period of atropine instillation (with plus lenses to help near work)
• Monocular occlusion
• Botulinum toxin to the medial rectus
• Psychological counselling (given that it is often associated to psychological
conditions)

Using short notes explain the investigation of a near exophoria in optometric practice [10 marks]

You perform MEM retinoscopy on a
patient (with the subjective refraction in
place) and find -1.00D RE and LE.
Which is the most likely diagnosis?
1. Accommodative insufficiency
2. Accommodative excess
3. Accommodative lag
4. Accommodative inertia
5. Convergence insufficiency

2

Which one of the following is not a
treatment for a decompensated
heterophoria at near?
1. Fusional reserves training
2. Refractive error modification
3. Prismatic correction
4. Flipper exercises
5. Exercises using stereograms

4

At a working distance of 33 cm you
measure 10Δ XOP for a –2.00DS myope
without their glasses. With the glasses on
you record a 2 Δ SOP. Using this
information what is the AC/A ratio for this
patient?
1. 2:1
2. 4:1
3. 6:1
4. 8:1
5. 10:1

3