This document discusses various anomalies of accommodation and convergence that can cause asthenopia (eye strain) including presbyopia, accommodative insufficiency, ill-sustained accommodation, accommodation inertia, paralysis and spasm of accommodation, as well as convergence insufficiency, paralysis, and spasm. It describes the causes, clinical features, and treatment options for each condition. The management typically involves optical correction, orthoptic exercises, and in some cases surgery to improve binocular vision and reduce symptoms.

1. Anomalies of accommodation,
convergence & management
Mohammad Arman Bin Aziz
Instructor, Optometry
ICO

2. Asthenopia
• Term for describing a number of symptoms
like:
Eyestrain
Easy fatigability after reading
Heaviness of lids
Sleepiness after reading
Headache

3. Causes of Asthenopia
• Uncorrected refractive errors.
• Defects of ocular motility.
• Accommodation and convergence anomalies

4. Accommodation
The process by which the crystalline lens
changes its power.
Association with
Convergence
Pupillary miosis
Near triad

5. Anomalies of accommodation
• Diminished or deficient accomodation:
– Physiological( presbyopia)
– Pharmacological (cycloplegia)
– Pathological
• Insufficiency of accommodation
• ill-sustained accommodation
• Inertia of accommodation
• Paralysis of accommodation

6. Cont.…
• Increased accommodation:
– Excessive accommodation
– Spasm of accommodation

7. Presbyopia (eyesight of old age)
• Not an error of refraction.
• Condition of physiological insufficiency of
accomodation.
• Progressive fall in near vision.

8. causes
• Age related changes in the lens which
includes:
– Decrease in the elasticity of lens
– Increase in the size and hardness(sclerosis) of lens
substance which is less easily moulded.
• Age related decline in ciliary muscle power

9. Symptoms:
• Difficulty in near vision
• Asthenopic symptoms
• Intermittent diplopia at near because of
interrelationship between accommodation
and convergence.

10. Management
• Optical correction:
– Convex lenses of appropriate power.
• Add:
– difference between the distance correction and the
strength needed for near vision.
• A rough estimate for the presbyopic add for various age
levels is:
– 45 years: +1.00 to +1.25Ds
– 50 years: +1.50 to +1.75Ds
– 55 years: +2.00 to +2.25Ds
– 60 years: +2.50 to +3.00Ds

11. Surgical treatment
• Corneal procedure:
– non ablative corneal procedure
– Laser based corneal procedure
• Lens based procedure
– Refractive lens exchange(RLE)
– Phakic refractive lens
• Sclera based procedure
– Anterior ciliary sclerotomy with tissue barrier
– Scleral spacing procedure.
– Scleral ablation with Erbium(Er.):YAG laser

12. Insufficiency of accommodation
• Accommodative power less than normal
physiological limits for patient ‘s age.
• Should not be confused with presbyopia in
which the physiological insufficiency of
accommodation is normal for age.

13. causes
• Premature sclerosis of lens
• Weakness of ciliary muscle due to systemic causes of
muscle fatigue like:
• Debilitating illness
• Anemia
• Malnutrition
• Diabetes
• Stress
• Weakness of ciliary muscle due to local causes like
irodocyclitis.

14. Clinical features
• Headache, fatigue and irritability of eye.
• Near work is blurred
• Intermittent diplopia
• Asthenopic symptoms >>> blurring of vision

15. • The above symptoms are stable in the
accommodative insufficiency of lenticular
origin.
• When the condition is due to ciliary muscle
weakness, the symptoms may improve:
– with the improvement of exciting factor
– betterment in general health
– Relaxation from work or worry

16. Treatment
• Treatment of the cause.
• Near vision spectacle.
• Accommodation exercise.

17. Ill sustained accommodation
• Condition of accommodation fatigue.
• Although the range of accommodation is
normal, it cannot be sustained for a sufficient
time.
• Causes patient’s NPA to recede during close
work.

18. Clinical features
• Symptoms similar to that of accommodative
insufficiency.
• Pt. complains of tiredness very soon on
intense near work.
• Pt’s NPA gradually recedes and near vision
becomes blurred.

19. Treatment
• Curtailing the near work during:
– Debilitating illness
– General tiredness
– When pt. is relaxed in bed
• Visual hygiene with good illumination and
posture during study.

20. Accommodation inertia
Also known as accommodative infacility.
Condition of difficulty in adjusting the
accommodation according to the distance of
the object of regard so as to gain clear vision.
Cycles per minute by flipper
Usually rare condition.

21. Clinical features
It takes some time and effort to focus a near
object after looking at distant.
Usually does not assume any serious
preposition.
Occasionally may give rise to some trouble
and annoyance.

22. Treatment
• Correcting any associated refractive error.
• Accommodation exercise.

23. Paralysis of accommodation
Also known as cycloplegia.
Complete absence of accommodation.

24. Causes
• Drug induced: due to the effect of atropine,
homatropine or other parasympatholytics.
• Internal ophthalmoplegia(paralysis of ciliary
muscle and sphincter pupillae) associated
with:
• Diphtheria, diabetes, chronic alcoholism, cerebral or
meningeal diseases and mild head injury.
• Paralysis of accommodation as a component
of complete 3rd nerve paralysis..

25. Clinical features
Blurring of near vision (previously
emmetropic and hyperopic eye).
Photophobia (glare).
Examination reveals abnormal receding of
near point and markedly decreased range of
accommodation.

26. Treatment
• Self recovery occurs in drug induced paralysis
and diphtheria cases.
• Dark glasses to reduce glares.
• Convex lens for near vision if paralysis is
permanent.

27. Lag of accommodation
• Accommodative response is
smaller than accommodative
demand.
• Causes asthenopic symptoms.
• Can be found by dynamic
retinoscopy.
• Corrected by giving addition
for near.

28. Excessive accommodation
Pt. exerts more than normal accommodation
for performing certain near work.
It is within voluntary control and is
intermittent process.
Whereas, spasm of accommodation is the
prolong use of excessive accommodation.

29. causes
Young hyperopes frequently use excessive
accommodation as a physiological adaptation.
Young myopes performing excessive near work
may also use excessive accommodation in
association with excessive convergence.
Astigmatic error in young person
Use of improper or ill- fitting spectacle.

30. Precipitating factor
Large amount of near work.
Low or excessive illumination of working
environment.
General debility, physical and mental ill
health.

31. Clinical features
Varying degree of blurred vision
(pseudomyopia}.
Symptoms of accomodative asthenopia.
Both far and near point are brought nearer to
the eye.

32. Treatment
• Optical correction: refractive error corrected
after cycloplegic refraction.
• General treatment:
– Near work should be forbidden for a period.
– Thereafter it should be curtailed.
– General health condition should be maintained.

33. Spasm of accommodation
• Spasm of accommodation refers to exertion
of abnormally excessive accommodation,
which is out of voluntary control of the
individual.

34. Causes
• Drug induced: strong miotics like echothiophate.
• Spontaneous spasm: children with high
refractive error.
• Iridocyclitis: causes ciliary spasm

35. CONT….
• Spasm of near reflex: seen in tensed or
disturbed individuals with excessive
accommodation, convergence and miosis.
• Lesion of the brain: meningitis , encephalitis are
associated with ciliary spasm.
• Toxic reaction of poison: eg sulphonamides,
arsenic, smoking

36. Clinical features
• Blurring of vision due to induced pseudomyopia.
• Headache and browache.
• Near point is abnormally close.

37. Treatment
• Relaxation of ciliary muscle: complete ciliary
paralysis with atropine for 4 weeks or more.
• Optical treatment: proper refractive correction in
the presence of ametropia.
• General treatment:
– near work should be forbidden or curtailed.
– The general condition of the patient should be improved.

38. Convergence
• Disjugate movement
• Both eyes move inward so that the lines of sight
intersect in front of eye.
• Allows bifoveal single vision maintained at any
fixation distance.
• Does not deteriorate with age.
• May deteriorate in certain abnormal conditions.
• Can be improved by exercises.

39. Anomalies of convergence
• Convergence insufficiency:
– Inability to obtain or maintain adequate
binocular convergence.
– Most common cause of ocular asthenopic
symptoms.

40. Etiology
• Primary or idiopathic:
– In many cases, exact etiology is not known.
– May be associate with:
• Wide IPD
• Delayed or inadequate functional development
• General debility
• Psychological instability
• Over work or worry

41. • Refractive :
– Associated with uncorrected high hyperopia and
myopia.
• Diseases of the accommodative convergence
mechanism result in convergence insufficiency
in patients as follows:
– High hyperopes (>5D) usually make no effort to
accommodate and there is deficient accommodative
convergence.
– Myopes may not need accommodation and thus lack
accommodative convergence.

42. • Presbyopia:
• Muscular imbalances
– Exophoria
– IXT
– Vertical muscle imbalances
• Consecutive convergence insufficiency :
– May occur following either recession of medial
recti or resection of lateral rectus muscle.

43. Clinical features:
• Clinical problem in patient who does intense
near work.
– Children with increased school work.
– Desk workers
– Computer users
– Precision workers
• Symptoms can be divide as:
– Symptoms due to muscular fatigue
– Symptoms due to failure to maintain BSV

44. Symptoms due to muscular fatigue
• Due to continuous use of neuromuscular power.
• Eye strain and sensation of tension around globe.
• Headache and eye ache after intense near work and
relieved when eyes are closed.
• Difficulty in changing focus from distance to near
objects.
• Itching, burning and soreness of eyes and even
hyperemia of nasal half of the conjunctiva.

45. Symptoms due to failure to
maintain BSV
• Blurred vision and crowding of words while
reading.
• Intermittent crossed diplopia for near under the
condition of fatigue.
• Characteristically one eye will be closed or closed
while reading to obtain relief from visual fatigue.

46. Treatment
• Excellent prognosis in majority cases.
• Optical:
– proper refractive correction for any presence of
ametropia.
– Myopes given full correction and hyperopes
undercorrected to stimulate accommodation.
– In adults older than 40, proper presbyopic correction
should be given.

47. Orthoptic treatment
• Exercise to improve NPC:
– Advancement exercise(pencil push up exercise)
– Jump convergence exercise
• Exercise to increase amplitude of fusional
convergence:
– Convergence exercise with prisms(BO)
– Convergence exercise using synoptophore
– Exercise using convergence card.
– Physiological diplopia exercise using stereogram in the
uncrossed position.
– Convergence exercise using diploscope.

48. • Training of voluntary convergence.
• Relaxation exercises:
– Physiological diplopia exercise using cat stereograms
in crossed position.
– Divergence exercise on synaptophore
– Divergence exercise on prisms
• Prism therapy:
– Base –in prism reading glasses or bifocals with
prism in the lower segment are useful as relieving
prism.
– Relieving prisms and bifocals should be avoided in
young age.

49. Surgical treatment
• As a last resort, when all other measures fail.
• When it is associated with large exophoria at
near.
• Medial muscle resection can be performed in
one or both eyes.

50. Convergence paralysis:
• Total lack of convergence.
• Etiology:
– Occurs Secondary to some organic diseases of the brain.
– The organic brain lesions are:
• Head injury
• Encephalitis
• Disseminated sclerosis
• Tabes dorsalis
• Narcolepsy
• Tumors

51. Clinical features
• Convergence is completely absent.
• Exotropia and crossed diplopia occurs on
attempted near fixation.
• Accommodation is usually normal. But in
some case it may be reduced or absent.

52. • Parinaud’s syndrome : convergence
paralysis associated with vertical gaze
paralysis.
• Pretectum-posterior commissure syndrome
(dorsal mid brain syndrome):
– Commonly caused by tumor in pineal gland
– Common features are:
• Convergence paralysis
• Vertical gaze paralysis
• Bilateral fourth nerve paralysis
• Lid retraction may occur in some patient.

53. Treatment
• Base in prisms are prescribed at near to alleviate
the diplopia at near.
• Plus lenses with base in prisms in patient with
accommodation insufficiency.
• Occlusion of one eye at near.
• Eye muscle surgery is contraindicate.

54. Convergence spasm
Characterized by intermittent episodes of
maximal convergence usually associated with
spasm of accommodation.

55. • Etiology :
– Functional causes:
• In most of the cases cause is functional.
• In patient with hysteria or neurosis.
– Organic causes:
• Rarely associated with organic lesions like:
– Head trauma
– Encephalitis
– Tabes
– Pituitary adenomas
– Posterior fossa neurofibroma
– Arnold-chiari malformation

56. Clinical features
• Most cases: condition is episodic
• Extreme convergence: eyes in extreme
convergence position resembling abducens palsy.
• Intermittent diplopia
• Blurring of vision.
• Miosis
• Induced myopia
• Psychiatric examination reveal hysteria and
neurosis.

57. Management
• Neurological evaluation: organic lesions are rare
cause of convergence spasm.
• Prolonged atropinization with plus lenses for
near.
• Altered monocular occlusion
• Psychiatric work up and therapy as long term
mearure.

58. References
• Optics and refraction; A.K Khurana
• Clinical refraction; Irvin M Borish, 3rd edition
• Clinical procedures in optometry