Accommodative Anomalies

Question 1

What are some examples of accommodative anomalies and are they defective or excessive?

Answer 1

Defective:
- Accommodative Insufficiency

• Accommodative Fatigue
• Accommodative Paralysis
• Accommodative Inertia (failure to alter)

Excessive:
- Accommodative Spasm

Question 2

What is the definition of Accommodative Insufficiency?

Answer 2

Near point of accomm consistently below that expected for age and refractive error.

Usually bilateral

Question 3

What are the Symptoms/Findings of Accommodative Insufficiency in relation to:

• Near vision?
• Uniocular and binocular - NPA?
• Dynamic ret?
• Deviation?
• Micropsia?

Answer 3

• Near Vision
  Blurred
• Uniocular & Binocular NPA
  Reduced for Age
• Dynamic RET
  Increased Accommodative Lag
• Deviation
  Effort might produce Eso
• Micropsia
  Rare illusion in severe cases

Question 4

What is Accommodative Fatigue?

Answer 4

Accomm is initially sufficient but reduces with continued exertion

Bilateral

Question 5

What are the Symptoms/Findings of Accommodative Fatigue in relation to:

• Near vision?
• Uniocular and binocular - NPA?
• Dynamic ret?
• Micropsia?
• When does it occur?

Answer 5

• Near Vision
  Blurred
• Uniocular & Binocular NPA
  Reduced on repeated testing (unioc and binoc)
• Dynamic RET
  Increasing lag of accommodation
• Micropsia
  Rare
• When does it occur?
  With prolonged near work, can be relieved by rest

Question 6

What is Accommodative Inertia?

Answer 6

Difficulty in altering accomm - delay in either exerting or relaxing accomm

Bilateral

Question 7

What are the Symptoms/Findings of Accommodative Inertia in relation to:

• Blur
• Uniocular and binocular - NPA?
• Dynamic RET
• Accommodative Facility

Answer 7

• Blur
  When changing focus/distance
• Uniocular and binocular - NPA?
  Possibly normal
• Dynamic RET
  Possibly normal accommodative lag
• Accommodative Facility
  Reduced

Worse in poor illumination

Question 8

What is Accommodative Paralysis?

Answer 8

• Inability to exert any accomm
• Blurred vision for all distances closer than infinity*
• Unilateral or bilateral

Question 9

What are the Symptoms/Findings of Accommodative Paralysis in relation to:

• Blur
• Uniocular and binocular - NPA?
• Dynamic RET
• Micropsia
• Pupils
• Photophobia
• Diplopia

Answer 9

• Blur
  Increasing blur as fixation moves from infinity towards patient
• Uniocular and binocular - NPA?
  Unable to measure
• Dynamic RET
  Unable to measure
• Micropsia
  Present
• Pupils
  Possibly dilated (depending on aetiology)
• Photophobia
  If pupil dilated
• Diplopia
  If convergence paralysis present too

Question 10

What is Macropsia?

Answer 10

• Objects appear larger than natural size.
• When there is an excess of accommodation, reduced effort or no effort is required to focus on a near object.
• The brain interprets the near object producing the retinal image as being further away.
• The near object is judged to be a larger than normal object in the distance.

Question 11

What is Micropsia?

Answer 11

• Objects appear smaller than natural size.
• In a defect of accommodation, excessive accommodation is required to focus on a near object.
• The brain interprets the retinal image as produced by an object close to the eye.
• The object is judged to be smaller than its natural size

Question 12

What drugs/medication can cause accommodative deficiency?

Answer 12

• Anticholinergics
• Neuroleptics & antipsychotics
• Bladder spasmolytic drugs
• Antihistamines (long term use)
• Antidysrhythmic drugs
• Tricyclic antidepressants

Important to ask about meds and be aware this could reduce accommodation

Question 13

What are Anticholinergics?

Answer 13

e.g. Scopolamine patch used for: motion sickness, nausea, vomiting

Or used to reduced drooling in children with disabilities

Firth and Walker (2006) found reduced accomm in this cohort

Question 14

What are Neuroleptics & Antipsychotics?

Answer 14

e.g. Phenothiazines

Used in schizophrenia

Reduce accomm by 40-100% (Thaler, 1979)

Question 15

What are Bladder Spasmolytic Drugs?

Answer 15

e.g. Propiverine

Reduces accomm in children if high dose (Arfwidsson, 2007)

Question 16

What are Antidysrhythmic Drugs?

Answer 16

e.g. Cibenzoline

Restore normal heart rhythm

Severely decreased accomm (Frucht et al, 1984)

Question 17

What are Tricyclic Antidepressants?

Answer 17

e.g. Lorazepam

(Jung et al, 2012) - found reduced accommodation

(Speeg-Schatz et al, 2001) - found it affects convergence but not accomm

Question 18

How do we manage:
Accomm Insufficiency,
Accomm Fatigue,
Accomm Inertia?

Answer 18

1) Correct refractive error

2) Treat any underlying cause

3) Orthoptic accommodative exercises

Question 19

What did Horwood & Toor (2014) find out about accommodation and accommodation exercises?

Answer 19

Simple conv exercises are more effective at improving accomm than accomm exercises!

Question 20

What other management can we use in Accommodative Deficiency?

Answer 20

Plus correction for near work (if no response to Tx aka treatment)

Wahlberg et al (2010) suggests +1DS instead of +2DS

Bifocal wear in Downs Syndrome

?Counselling/ referral to clinical psychologist

?Functional –> Dynamic Retinoscopy and +/- lenses

Question 21

What management is there for accommodative paralysis?

Answer 21

• Treat cause
• Correct Rx
• Not able to exercise
• Prescribe reading addition (+ lens)
• Painted contact lens if pupil dilated
• Counselling / referral to clinical psychologist
• Base in prism (if convergence paralysis too)
• Miotics (e.g. Pilocarpine) rarely given (Reduce accomm effort needed for clear image)

Question 22

What is an example of Accommodative Excess?

Answer 22

Accommodative Spasm

Question 23

What is Accommodative Spasm?

Answer 23

A condition where the ciliary muscle is contracted and cannot be relaxed, therefore accommodation is continuously exerted.

Question 24

What are the Symptoms/Findings relating to Accommodative Spasm relating to:

• Blur
• Diplopia
• Pupils
• OM
• Dynamic RET
• Macropsia
• VA

Answer 24

• Blur
  Yes
• Diplopia
  Variable ET, associated with excessive convergence
• Pupils
  Miosis
• OM
  Spasm on lateral gaze gives appearance of LR palsy
• Dynamic RET
  Accommodative lead
• Macropsia
  Possible
• VA
  Reduced due to pseudo-myopia

Question 25

What is pseudo-myopia?

Answer 25

Spasm of the ciliary muscle prevents relaxation of accommodation so distance is blurred

Question 26

What are the causes of Accommodative Spasm?

Answer 26

- Functional (underlying emotional response) - Late onset myopia / sudden myopic increase - Uncorrected hypermetropia - Lack of relaxation after close work (mild) - Manipulation of accomm to control ocular alignment (XT) - Closed head trauma - Rostral midbrain lesion - MS - Increased intracranial pressure (single report Kawasaki & Borruat 2005) - Drugs

Question 27

What are some drugs that can cause accommodative spasm and what did Pula et al (2013) find?

Answer 27

Parasympathomimetics e.g. pilocarpine – used to treat glaucoma (induce accom) Anticholinesterase agents Pula et al (2013) Lit review of systemic meds which result in neuro-ophthal side effects (includes accomm) and provides some info on why these occur

Question 28

How do we investigate Accommodative Spasm?

Answer 28

Observe patient throughout testing Observe consistency of miosis, convergence spasm Test abduction (may need to use doll’s head) Cycloplegic refraction NB Acute myopia can be an adverse reaction to some drugs (e.g. Topiramate – epilepsy/migraines). There is no miosis and no convergence spasm

Question 29

How do we manage Accommodative Spasm?

Answer 29

- Correct refractive error - Re-assure and visual rest – do nothing! Will resolve if no underlying neurological disease - If it is a child – tell the parent to stop asking about it - Consider counselling / clinical psychologist – if needed to remove the stress factor - Cycloplegics with reading correction - BT to medial recti - If functional then miotics/saline placebo

Question 30

What else must we consider when we suspect Accommodative issues?

Answer 30

- Premature presbyopia - Computer Vision Syndrome (CVS) - Special needs children: Cerebral palsy & Downs syndrome

Question 31

What is the typical age of onset of presbyopia?

Answer 31

40 - 50 years of age

Question 32

How do we treat Presbyopia?

Answer 32

+ve lenses

Question 33

When might premature presbyopia occur?

Answer 33

Review paper is Sonali et al (2024)!!! May purely reflect extremes of normal or be due to: nutritional, environmental, or disease-related causes - Sunlight (ultraviolet radiation) – premature degradation of crystalline lens (Priyambada, 2019) - Tobacco users (Fasih et al, 2014) - Type 1 Diabetes (Sırakaya et al, 2020) - HIV and AIDS (Mathebula & Makunyane, 2017)

Question 34

What is Computer Vision Syndrome (CVS)?

Answer 34

Term used for complaints of computer users which include: - Eyestrain - Eye Fatigue - Burning Sensations - Dry Eyes - Irritation - Redness - Blurred Vision - Delay in Focusing - Diplopia

Question 35

Why does computer vision syndrome occur?

Answer 35

Excessive exposure to intense light, incl blue light, from screens may result in CVS

Question 36

What did Cheng et al. (2014) find out about blue light filter glasses?

Answer 36

No sig effect on tear production and dry eyes but patients did report a sig improvement in comfort (Cheng et al 2014)

Question 37

What did Dabrowiecki et al. (2019) find out about blue light filter glasses?

Answer 37

Improvement in symptoms but not sig (Dabrowiecki et al 2019)

Question 38

What did The College of Optometrists (2018) say about blue light filter glasses?

Answer 38

‘The best scientific evidence currently available does not support the use of blue-blocking spectacle lenses’

Question 39

What's the management of CVS?

Answer 39

Rosenfield (2011) - Treat any apparent accomm or conv anomaly - Ensure refractive correction for distance of monitor (‘middle distance’) - Blinking - Take rest breaks

Question 40

What is Accommodation like in Cerebral Palsy?

Answer 40

- 42% children have poor accommodation (Leat, 1996) - Greater accommodative lag in those with more severe motor impairments (McClelland et al, 2006) - Near pupil response found to be a ‘useful indicator’ of accommodative response with 83% sensitivity and 72% specificity (Saunders et al, 2008)

Question 41

What is Accommodation like in Down's Syndrome?

Answer 41

Accommodation reduced - 80% children with Down’s had reduced accommodation c/w controls (Woodhouse et al, 1993) - Less accurate (Anderson et al, 2011) - Under accommodation more likely where hypermetropia present and strabismus present (Stewart et al, 2007)

Question 42

What is suggested in Down's Syndrome with CI?

Answer 42

Bifocals suggested - Improved accuracy in accommodation (Stewart et al, 2005) - Literacy skills improve faster (Nandakumar et al, 2011)

Question 43

How would we test accommodative abilities in Down's Syndrome cases?

Answer 43

Use dynamic RET if unable to perform accomm tests (also useful in younger patients and functional cases)