This document discusses myopia, also known as nearsightedness. Myopia occurs when light focuses in front of the retina rather than directly on it, causing distant objects to appear blurry. It can be caused by increased axial length of the eye or a change in curvature or index of the eye's refracting surfaces. Myopia is classified based on degree of nearsightedness and age of onset. Simple myopia develops gradually during childhood and adolescence. Progressive myopia is associated with degenerative changes in the eye structures like the retina and sclera. Treatment options include optical correction with glasses or contact lenses as well as refractive surgeries like LASIK.

1. MYOPIA
MYOPIA
NISHITA AFRIN
B.OPTOM
3RD Batch
INSTITUTE OF COMMUNITY OPHTHALMOLOGY

2. MYOPIA

3.  myein = “to shut” (Greek)
 ops = eye (Greek)
 nearsightedness
 is a condition of the eye where the light that comes
in does not directly focus on the retina but in front of
it, causing the image that one sees when looking at
a distant object to be out of focus, but in focus when
looking at a close object.

4. BY DEFINITION
Is a shortsightedness where parallel rays of light
coming from infinity are focused in front of the retina
when accommodation is at rest

5. MECHANISMS OF PRODUCTION
o Axial myopia
o Curvatural myopia
o positional myopia
o index myopia
o myopia due to excess accommodation

6. 6
 Optics of myopia
 Far point is finite (In front of the eye)
 Emmetropic eye it is at infinity
 Higher the myopia the shorter the distance
 Far point is 1meter from the eye ,there is 1D of
myopia
 Nodal point is further away from retina
• Accommodation need not develop
normally resulting in Convergence
insufficiency and Exophoria

8. CAUSES OF MYOPIA
 Stretched eye
 Hereditary
 Biological variant- axial length
 Hormonal secretions to the scleral tissue
 Endocrine secretion
 Absence of vitamin A- corneal distortion
 Fatigue

10. CAUSE
 All myopia appears to cause by one of the follow:
 Increased axial length
 Shortened radius of curvature of one of
the refracting surfaces.
 Changed index of one of the media
 Decreased depth of anterior chamber.

12. CLASSIFICATION OF MYOPIA
According to amount (Clinical Refraction 3rd edition – Borish)
Classically
Very low- up to –1.00D
Low – 1.00D to –3.00D
Medium -3.00D to –6.00 D
High –6.00D to –10.00D
Very high above –10.00D

13. CLASSIFICATION OF MYOPIA
Age of onset – Grosvenor 1987
Congenital myopia: at birth esp. with LBW
Youth onset myopia:6years to teenage years.
Early adult onset myopia: age 20 to 40 years.
Late adult onset myopia: beyond the year 40.

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CLINICAL CLASSIFICATION
 Congenital Myopia
 Simple Myopia
 Degenerative Myopia
 Nocturnal Myopia
 Pseudo Myopia
 Induced Myopia

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Congenital myopia
 Frequently seen in Premature babies
 Marfan’s syndrome
 Homocystinuria
 Increase in axial length
 Increase inOverall globe size
 Since birth, diagnosed at age 2-3
years
 If unilateral, as anisometropia, may
develop amblyopia, strabismus
 Usually 8-10 D, remain constant
 Bilateral- difficulty in distant vision,
hold things very close

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 Associated conditions
Congenital Convergent squint
Cataract
Microphthalmos
Aniridia
Megalocornea
Congenital Separation of retina
Management
 Early Correction is desirable
 Retinoscopy under full cycloplegia
 Early full correction desirable
 Poor prognosis

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Simple / developmental myopia
 Also known as physiological or school myopia
 Physiological error not associated with any
disease of the eye
 Etiology :
 Not genetically determined
 Inheritence is autosomal dominant

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 Associated factors
 Role of diet

 Theory of excessive near work

20. 20
 Clinical picture
 Rarely present at birth
 Rather born hypermetropic, become myopic
 Begins at 7-10 years, stabilizing around mid
teens
 Usually around 5D, never exceeds 8D

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Symptoms
 Poor vision for distance
 Asthenopic symptoms develop due to
dissociation between accommodation and
convergence
 Convergence weakness, exophoria,
suppression
 Excessive accommodation inducing ciliary
spasm and artificially increasing the amount of
myopia
 Psychological outlook

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 Signs
 Large and prominent
 Deep AC
 Large, sluggishly reacting pupils
 Normal fundus, rarely crescent
 Usually doesn't exceed 6-8D
Retinoscopy under full cycloplegia

23. 23
Pathological / degenerative / progressive
myopia
 Rapidly progressive associated with
degenerative changes in the eye
 Etiology
 Rapid axial growth of the eyeball outside the
normal biological variations of development
 Role of heredity
 Role of general growth process

25. 25
Genetic factors General growth process
More growth of retina
Stretching of sclera
Increased axial length
Degeneration of choroid
Degeneration of retina
Degeneration of vitreous

26. 26
Symptoms
 Defective vision
 floating black opacities
 Night blindness

27. 27
Signs
 EYE Large, prominent eyes simulating exophthalmos
 CORNEA large
 ANTERIOR CHAMBER deep
 PUPILS are large and sluggish reacting to light
 LENS show opacities at the posterior pole due to aberration of
lenticular metabolism and due to overstretching anterior
dislocation may also occur
 VITEROUS degeneration,viterous liquefication,vitreous
detachment present as WEISS REFLEX
 SCLERA thinning resulting in formation of STAPHYLOMA
 VISUAL FIELD DEFECTS show Contraction and in some ring
scotomas present

28. Posterior vitreous detachment
myopic patient
posterior staphyloma
in B-scan

29. 29
 DISC
 Large in size
 Myopic Crescent on the temporal side of
the disc
 Inverse myopia Myopic crescent situated
nasally and supertraction of the retina
temporally
 called as INVERSE CRESCENT
 Peripapillary Atrophy

30. Myopic crescent

31. 31
 MACULA
Foster-Fuchs fleck
 RETINAL DETACHMENT
 POSTERIOR STAPHYLOMA
 RETINAL HOLES
 TESSELLATED FUNDUS

32. FOSTER FUCHS SPOT
RETINAL
DETACHMENT

33. RETINAL HOLE

34. TESSELLATED FUNDUS

35. 35
Treatment
Optical treatment
 Appropriate concave lenses
 Minimum acceptance providing maximum vision

36. 36
GUIDELINES
LOW DEGREES OF MYOPIA (Up to -6D)
 IN YOUNG SUBJECTS
Defect should never be overcorrected and advised for
constant use to avoid squinting and develop a normal
ACCOMMODATION-CONVERGENCE reflex
 IN ADULTS
Receiving spectacle for the first time,have the ciliary muscle
that are unaccostomed to accommodate efficiently so that
lens of slightly lower power(1 or 2 D) may be prescribed for
reading,especially if engaged in to any greater extent.Above
the age of 40 years,when accommodation fails
physiologically, a weaker glass for near work is essential

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HIGH DEGREES OF MYOPIA
Full correction rarely be tolerated so we attempt to
reduce the correction as little as is compatible with
comfort for binocular vision. We prescribe the lens
with which the greatest visual acuity is obtained
without distress

38. MYOPIA CORRECTION
38

39. 39
ADVANTAGES OF SPECTACLES
 Economical
 Allow incorporation of prism,bifocals,pal which can be
used for the management of esophoria or any
accommodative disorders accompanying myopia
 Spectacles require less accommodation than contact
lens for myopia that likelihood of accommodative
asthenopia or near point blur in patients approaching
presbyopia may be less

40. SPECIAL LENS DESIGNING
 Any prescriptions above -15.00 D require
Special lens designs to provide optimal visual acuity
and cosmesis.
Special lenses for high myopia- 1. ASPHERIC
LENSES
2. LENTICULAR MINUS LENS
3.MYODISC

41. ASPHERIC LENSES

42. LENTICULAR MINUS DESIGNS

43. THE MYODISC

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SURGICAL TREATMENT
 Epikeratophakia
 RK
 PRK
 ISCR
 Phakic IOL’S
 LASIK
LASIKPRK
RK
ISCR
Phakic IOL’S

48. THANK
YOU