Accommodation & Anomalies of Accommodation Presented by Anand Trivedi

1. • Topic:-Accommodation
• Presented By:-
• ANANDTRIVEDI

2. • Definition
In an emmetropic eye,
parallel rays of light
coming from infinity are
brought to focus on the
retina, with
accommodation at rest.

3. • Farpoint&
Nearpoint
▪ The nearest point at which Small object can be
seen clearly is called near point or punctum
proximum &
▪ The distance point is called far point or
punctum remotum.
▪ Distance between the Far point and near point
called range of accommodation.
▪ Diffrence between the dioptric power needed to
focus at near point(P) and Far point ® is called
amplitude of accommodation(A).
▪ Thus A=P-R.

5. • PointsTobe
Known
▪In Hypropic eye, Far point Is virtual
And lies behind the eye.
▪In Myopic eye, Far point is real And lies
in front of the eye.
▪In an emmetropic eye, Far point is at
infinity and near point Varies with
age…

6. • Depth
ofField
▪The range of distance from the eye
in which an object appears clear
without change in accommodation
is termed Depth of Field

7. DepthofFocus
▪The range at the retina in which an
optical image may move without
impairment of clarity is termed as
Depth of Focus.

10. Tyepes of accommodation:-
1. Tonic accommodation
2. Proximal
accommodation
3. Reflex accommodation
4. Convergence
accommodation.

14. Anomalies of accommodation:-
• Presbyopia
• Insufficiency of
accommodation
• Paralysis of accommodation &
• Spasm of accommodation

15. 1.Presbyopia:-
Presbyopia is a condition of physiological
insufficiency of accommodation leading to a
progressive fall in near vision.

17. Causes:-
Decrease in the accommodative Power of lens with
increasing age , leading to presbyopia,occurs due
to:
1. Age realated changes in the lens
- Decrease in the elasticity of lens capsule
- progressive increase in size and hardness
(sclerosis) of lens substance which is less easily
moulded.
2. Age related decline in cilliary muscle power.

18. Premature presbyopia:-
• Uncorrected hypermetropia.
• Premature sclerosis of the lens.
• General debility causing.
presenile weakness of cilliary
muscle.
• Chronic simple glaucoma.

19. Symptoms:-
• Difficulty in near vision.
• Patients complaint of difficulty in reading
Small prints
• Asthenopic symptoms due to fatigue of
the cilliary muscles are also complained
after reading or doing any near work.
• Intermittent diplopia.

20. Treatment:-
1.Optical treatment:-
- Prescription of appropriate
convex glasses for near
work.
- Rough guide for providing
presbyopic glasses in an
emmetrope cam be made
from the age of the patient.
• 45 years: +1 to +1.25D
• 50 years: +1.5 to +1.75D
• 55 years: +2 to +2.25D
• 60 years: +2.5 to +3D

22. 2. Surgical Treatment:-
• Corneal procedures
- Non ablative corneal procedure
-Monovision CK(conductive keratoplasty)
- laser based corneal procedure
-Laser thermal keratoplasty
- Monovision Lasik
- presbyopic bifocal lasik
- presbyopic multifocal Lasik c

23. • Intraocular refractive procedure
- Refractive lens exchange
- phakic refractive lens
- Monovision with IOLs
• Scleral based procedures
- anterior sclerotomy with tissue Barriers
- scleral spacing procedure
- scleral ablation with erbium:- Yag Laser

24. 2. Insufficiency of
accommodation:-
• Condition in which
accommodative Power is
constantly less than lower limit
of normal range according to
patients age .

25. Etiology
• Premature sclerosis of lens
• Weakmess of cilliary muscles due to
systemic causes: Debilitating illness,
anemia, toxemia, malnutrition, DM,
Pregnancy,Stress etc.
• Weakness of cilliary muscles due to
local causes: POAG.

26. Clinical Features
• Eye strain or asthenopia
• Headache, fatigue & irritability of the
eyes , while attempting near work
• Intermittent diplopia
• It is stanble condition,if due to
sclerosis of lens but is not stable in
associated with cilliary muscles
weakness.

27. Treatment
1.Treatment of underlying cause is
essential.
2.Near vision spectacles in the
form of weakest convex lens
which allows adequate vision
should be given till the power of
accommodation improves.
3.Accommodation exercises help in
recovery,if the underlying
debility has passed.

28. 3. Paralysis of Accommodation:-
• Cycloplegia refers to complete absence of
accommodation
• Causes:
- Atropine,Homatropine Or other parasympatholytic
drug.
- Internal opthalmoplagia(Paralysis of Cilliary muscles
and sphincter pupillae)May result from neuritis
associated with diphtheria, syphilis, diabetes,
alcoholism,cerebral or meningeal diseases.
- Complete third Nerve paralysis may due to
intracranial or orbital causes.

31. 4.Excessive accommodation:-
• Accommodative response
is grater than the
accommodative stimulus.
• There is functional increase
in tonus of cilliary muscles,
results in a constant
accommodative effect.

35. 5. Spasm of accommodation:-
•Spasm of accommodation reefers to
exertion of abnormally excessive
accommodation.

37. ClinicalFeatures
&
Treatment
1.Defective vision due to induced
myopia .
2.Asthenopic symptoms are more
marked than the visual symptoms.
1.Relaxation of cilliary muscles by
Atropine for 4weeks or more and
2.Prohibition of near work allow prompt
recovery from spasm of
accommodation.
3.Elimination of the associated causative
factors to prevent the recurrence
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