Hypermetropia
BY
RAIN HEALTH CARE
EYE & LIFESTYLE DISEASE CONSULTATION & MANAGEMENT CENTER
WHAT IS HYPERMETROPIA
TYPES OF HYPERMETROPIA
ETILOGY OF HYPERMETROPIA
CLINICAL FEATURES OF HYPERMETROPIA
HYPERMETROPIA PPT
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Hypermetropia
1. HYPERMETROPIA
Hypermetropia is an error of refraction in which
parallel rays of light from infinity come to a focus
behind the retina when accommodation is at rest.
3. Axial hypermetropia
• Axial hypermetropia When the anterior/posterior length of the eyeball
is shorter than normal. (Normal axial length is 24mm). A decrease of
1mm in axial length produces a hypermetropia of 3.0D.
** all newborns are almost hypermetropic approximately +2.5D. This is
due to the shortness of the globe and is physiological.
** it may also occur pathologically when the retina is displaced forward
{RD, CSR, ORBITAL TUMORS, RETINAL TUMOR}
• ** In micro or nano ophthalmos where the axial length is less than
20.0 mm there is high hypermetropic.
4. Curvature hypermetropia
• Curvature hypermetropia When the curvature
of the cornea or lens is flatter than normal. An
increase of 1mm in its radius of curvature
produces a hypermetropia of 6.OD.
5. Index hypermetropia
• Index hypermetropia When the refractive
index of the media is less than normal
- Corneal refractive index - 1.37
- Refractive index of the cortex of lens - 1.38
- Refractive index of the nucleus of lens - 1.40
6. Clinical types of hypermetropia
• 1. Congenital hypermetropia
• 2. Simple or developmental hypermetropia
• 3. Acquired hypermetropia
1. Congenital hypermetropia: This is rare. It is usually
associated with other congenital anomalies of the eyeball
like microphthalmos.
2. Simple or development hypermetropia: It is the most
common type. A newborn baby is hypermetropic but with
age, the eyeball grows in size and the hypermetropia are
gradually diminished. If the growth of the eyeball is
retarded then hypermetropia persists.
3. Acquired hypermetropia: This is found in aphakic
conditions, commonly following extraction of the lens. This
hypermetropia is usually high about + 10.0 D.
7. Depending on clinical presentation hypermetropia can
be of different types
1. Simple hypermetropia: This is due to normal biological
variation in development of eyeball. This is the most
common type of hypermetropia.
2. Pathological hypermetropia: This is due to certain
factors which are not in the normal biological
variations, e.g. posterior subluxation of lens (positional
hypermetropia), acquired cortical sclerosis (index
hypermetropia), under-correction of refractive error
(consecutive hypermetropia) and congenital absence of
the lens (aphakia).
3. Functional hypermetropia: It results due to paralysis of
accommodation, e.g. third nerve paralysis.
8. Depending upon act of accomodation
• The hypermetropia which is seen after complete paralysis of
accommodation, after the application of atropine TH=MH+LH
• Latent hypermetropia: It is the amount of hypermetropia
which is corrected by the normal physiological tone of the
ciliary muscle. It is strong at a young age and slowly declines
with age.
• Manifest hypermetropia: The remaining portion which is not
corrected by the normal physiological tone of the ciliary
muscle is called manifest hypermetropia. It is hypermetropia
that remains uncorrected in normal circumstances. That is
when accommodation is not being actively used, or, in other
words, it is the total hypermetropia minus the latent
hypermetropia.
9. • This manifest hypermetropia is again made of two
components.
1. Facultative hypermetropia
2. Absolute hypermetropia
• 1. Facultative hypermetropia: It the part of hypermetropia,
which can be corrected by an additional effort of
accommodation or excessive the strain of the ciliary
muscle.
• 2. Absolute hypermetropia: Absolute hypermetropia is the
part of hypermetropia which cannot be overcome by active
exertion of accommodation.
10. Symptoms of hypermetropia
1. Headache
2. Eyestrain
3. Distance blurred vision
4. Difficulty in doing prolonged close work
12. Complication of hypermetropia
• Uncorrected hypermetropia leads to esophoria, which
later on may develop into esotropia. convergent squint
• hypermetropia with esophoria - To give full correction
• Hyperopia with exophoria - To give under e under
correction
• Hypermetropic individuals often have a shallow
anterior chambers. They have an increased
predisposition to develop narrow-angle glaucoma.
• Lid diseases: Repeated rubbing of eyes
in hypermetropic blurred vision may produce
blepharitis, stye, or chalazion.
• amblyopia- anisometropic, strabismic,ametropic