Myopia, also known as near-sightedness and short-sightedness, is an eye disease[5][6][7] where light from distant objects focuses in front of, instead of on, the retina.[1][2][6] As a result, distant objects appear blurry while close objects appear normal.[1] Other symptoms may include headaches and eye strain.[1][8] Severe myopia is associated with an increased risk of macular degeneration, retinal detachment, cataracts, and glaucoma.[2][9] Myopia results from the length of the eyeball growing too long or less commonly the lens being too strong.[1][10] It is a type of refractive error.[1] Diagnosis is by the use of cycloplegics during eye examination.[11] Tentative evidence indicates that the risk of myopia can be decreased by having young children spend more time outside.[12][13] This decrease in risk may be related to natural light exposure.[14] Myopia can be corrected with eyeglasses, contact lenses, or by refractive surgery.[1][15] Eyeglasses are the simplest and safest method of correction.[1] Contact lenses can provide a relatively wider corrected field of vision, but are associated with an increased risk of infection.[1][16] Refractive surgeries like LASIK and PRK permanently change the shape of the cornea. Surgeries like Implantable Collamer Lens (ICL) implant a lens inside the anterior chamber in front of the natural eye lens. ICL doesn't affect the cornea.[

1. MYOPIA
Presented By –
Dr Mohit Kumar Jha
Ophthalmology Resident
Civil Hospital , Panchkula

2.  SHORT SIGHTEDNESS
 DIOPTERIC CONDITION IN WHICH INCIDENT PARALLEL
RAYS COME TO A FOCUS ANTERIOR TO THE LIGHT
SENSITIVE LAYER OF RETINA WITH ACCOMODATION AT
REST.
MYOPIA

3. 1. Axial myopia
 Commonest form
 Increase in antero-posterior length of
the eyeball
2. Curvatural myopia
 Increased curvature of cornea, lens or both
3.Positional myopia
 Produced by anterior placement of
crystalline lens in eye
4.Index myopia
 Increase in the refractive index of crystalline
lens associated with nuclear sclerosis
5.Myopia due to excessive accomodation
ETIOLOGICAL CLASSIFICATION

4. 1. Congenital myopia
2. Simple or
developmental myopia
3. Pathological or
degenerative myopia
4. Acquired myopia
CLINICAL CLASSI.FICATION

5. AGE ONSET CLASSI.
CONGENITAL: since birth
YOUTH ONSET: Below 20 yrs. ( Simple
Myopia)
EARLY ADULT ONSET: 20-40: Acquired
Index myopia d/t Early NS
LATE ADULT ONSET: 40+ d/t Age NS

7. ◾Since birth
◾Diagnosed by 2-3 years
◾Mostly unilateral-Manifests as anisometropia
◾High degree of error: -8 to-10 D
◾Prematures, Marfan Sy, Homocystinuria
◾Associated with cataract, micropthalmos, aniridia, megalocornea,
congenital separation of retina
CONGENITAL MYOPIA

8. ◾ Developmental myopia- commonest variety
◾ School myopia (school going age 8 -12 years)
◾ Etiology
 Axial type:
 physiological variation in length of eye ball
SIMPLE MYOPIA
◾ Curvatural type
 Underdevelopment of eye ball
◾ Role of diet in early childhood
◾ Role of genetics – Autosomal Dominant
 Prevalence in children
 both parents myopic(20%)
 One parent myopic(10%)
 No parent myopic(5%)

9. SYMPTOMS
 Begins bet. 7 to 10 yrs. – about -5D, never exceeds -8D.
 POOR VISION FOR DISTANCE
 HALF SHUTTING OF EYES: Stenopaeic vision
 ASTHENOPIC: Pts with small degree of myopia- Strain
symp.
Convergence weakness, Exophoria , diplopia

10. ◾Signs
 Prominent eyeballs
 Anterior chamber - deeper than normal
 Pupils- Large, sluggishly reacting
 Fundus- normal; temporal myopic crescent may be seen
 Magnitude of refractive error
 Increasing at rate -0.5+- 0.30/ year.
 Does not exceed 6 to 8
◾Diagnosis
Confirmed by performing retinoscopy

11. ◾Degenerative/ progressive myopia
◾Rapidly progressive error which starts in childhood at 5-10 years of
age
◾High myopia in early adult life with degenerative changes
PATHOLOGICAL MYOPIA

12. ◾Role of heredity
 Heredity linked growth of retina is the determinant in
developmental myopia
 Sclera due its distensibility follows retinal growth but
choroid undergoes degeneration due to stretching, which
in turn causes degeneration of retina
 Progressive myopia is
 Familial
 More common in chinese,japanese,arabs and jews
 Uncommon among negroes,nubians and sudanese
ETIOLOGY

13. Genetic factors (play major role)
General growth process(minor)
More growth of retina
Stretching of sclera
Increase axial length
Degeneration of choroid
Degeneration of retina
Degeneration of vitreous

14. ◾Defective vision- uncorrectable loss of vision
◾Muscae volitantes
 Floating black opacities in front of eyes
 Degenerated liquified vitreous
SYMPTOMS

15. ◾Prominent eye balls
 Elongation of eye ball mainly affects posterior pole and
surrounding area
◾Cornea-large
◾Anterior chamber -deep
◾Pupils-slightly large ,react sluggishly to light
SIGNS

16. ◾Fundus examination:
Optic disc
 large and pale
Temporal edge presents a characteristic myopic
crescent- Atrophy of choroid - sclera visible
Peripapillary crescent encircling the disc may be
present, where choroid and retina is distracted
away from disc margin
Super traction crescent may be present on nasal side
(retina pulled
over disc margin)

19. Degenerative changes in retina and choroid
 Common in progressive myopia
 Characterized by white atrophic patches at macula with a little
heaping of pigment around them

21. • FOSTER-FUCH’S SPOT:
• Dark red circular patch
due to sub- retinal
neo vascularization
and choroidal
haemorrhage
• Present at macula

22. ◾Posterior staphyloma
 Due to ectasia of sclera at posterior pole
 It may be apparent as an excavation with vessels bending backward
over margins

23. ◾Degenerative changes in vitreous include:
 Liquefaction
 Vitreous opacities
 Posterior vitreous detachment(PVD)- Weiss’ reflex

26. ◾Retinal detachment/Tears
◾Myopic choroidal neovascularisation
◾NS
◾Vitreous haemorrhage
COMPLICATIONS

28. SECONDARY MYOPIA
INDEX:
• Nuclear Sclerosis
• Incipient Cataract
• Diabetic Myopia
CURVATURAL:
• Corneal- Ectasis, Keratoconus
POSITIONAL- Ant. Subluxation of lens
CONSECUTIVE- surgical overcorrection of Hypermetropia,
IOL

29. o DRUG INDUCED- Cholinergic – Pilocarpine,
Echothiophate,
o Steroid
o Sulphonamides

30. ◾Optical treatment of myopia
 Concave lenses
 Basic rule – minimum acceptance providing maximum
vision
◾Modes of prescribing concave lens-
1. Spectacles
2. Contact lens
TREATMENT OF MYOPIA

31. ◾Contact lenses are used in
case of high myopia as they
avoid peripheral distortion
and minification produced
by strong concave spectacle
lens

32. ◾Radial keratotomy
 Making deep radial incisions in peripheral part of
cornea leaving the central a 4mm optical zone
 These incisions on healing ; flatten the central
cornea thereby reducing its refractive power
 Correct low to moderate myopia(2-6D)
 DISADVANTAGES:
 Cornea is weakened – globe rupture in sports
persons
 Uneven healing – irregular astigmatism
 Patient may feel glare at night
SURGICAL TREATMENT OF
MYOPIA

34. ◾Photo refractive
keratectomy (PRK)
 A central optical zone of
anterior corneal stroma is
photoablated using
excimer laser (193nm uv
flash) to
cause flattening of central
cornea
 Correction for -2 to - 6D
of myopia

35. DISADVANTAGES:
Post operative recovery is slow
Pain and discomfort
Residual corneal haze in centre affecting vision
Expensive

36. ◾Refractory surgery of choice for myopia of upto -12D
LASER ASSISTED IN-SITU
KERATOMILEUSIS(LASIK
)

37. FLAP OF 130-160 MICRON
THICKNESS OF ANTERIOR
CORNEAL TISSUE IS RAISED
Midstromal tissue is ablated
directly with an excimer laser beam
ultimately flattening the cornea

39. 1. Patients >20 years
2. Stable refraction for at least 12 months
3. Motivated patient
4. Absence of corneal pathology
◾Absolute contraindication for LASIK
 Presence of ectasia
 Corneal thickness <450mm
PATIENT
SELECTION
CRITERIA

40. ◾Customised(C)-LASIK:
 Based on wave front
technology
 Corrects spherical,
cylindrical and other
aberations present in
eye
 Gives vision beyond
6/6 i.e.,6/5 or 6/4
ADVANCES IN LASIK

41. ◾Epi-(E) LASIK:
 Only epithelial sheet is
separated with Epiedge
Epikeratome
 Devoid of complications
related to corneal
stromal flap

43. ◾Minimal or no postoperative pain
◾Recovery of vision is very early as compared to PRK
◾No risk of perforation during surgery and rupture of globe
due to trauma like RK
◾No residual haze unlike PRK where subepithelial
scarring may occur
◾LASIK is effective in correcting myopia of -12D
ADVANTAGES OF LASIK

44.  Expensive
 Requires greater surgical skill than RK and PRK
 Flap related complications
 Intraoperative flap amputation
 Wrinkling of flap on repositioning
 Postoperative flap dislocation/subluxation
 Epithelization of flap – bed interface
 Irregular astigmatism
DISADVANTAGES

47. ◾Intraocular contact lens implantation for correction of
myopia of >12D
◾Special type of IOL is implanted in anterior chamber or
posterior chamber anterior to natural crystalline lens
PHAKIC INTRAOCULAR LENS

48. ◾Into the peripheral cornea at approximately 2/3rd
stromal depth
◾Flattening of central cornea, decreasing myopia
◾Advantage: reversible procedure
INTRACORNEAL RING (ICR)
IMPLANTATION

49. ◾A non-surgical reversible method of molding the cornea with
overnight wear unique rigid gas permeable contact lenses
◾Myopia correction upto -5D
◾Used in patients below 18 years of age
ORTHOKERATOLOGY

50. ◾General measures :
 Balanced diet rich in vitamins and proteins
 Early management of associated debilitating disease
◾Low vision aids
 indicated in patients with progressive myopia with
advanced degenerative changes
◾Prophylaxis
Genetic counselling

51. THANK YOU