This PPT is very beneficial for undergraduate Medical Students

1. Dr. Atul Kumar Anand
Senior Resident
AIIMS Patna

2.  when the parallel rays of light
coming from infinity are
focused at the sensitive layer of
retina with accommodation
being at rest.
 The component that maintains
the emmetropization are axial
length, Refractive index of lens
and corneal curvature.

3. 24-25mm
43 diopters
18 diopters
Accomodation at rest

4. A condition of refractive error the parallel rays of
light coming from infinity (with accommodation at
rest) are focussed either in front or behind the retina
in one or both the meridian i.e. the second principal
focus of the eye doesn’t fall on the retina.

5. Myopia: parallel rays of light coming from infinity are focussed
in front of retina when accommodation is at rest.
Hypermetropia/hyperopia: parallel rays of light coming from
infinity are focussed behind the retina when accommodation
is at rest.
Astigmatism: refractive error wherein the refraction varies in
different meridia. Consequently, the rays of light entering the
eye cannot converge to a point focus but forms a focal lines.

6. It is the refractive state of eye where in
parallel rays of light coming from infinity
are focused behind the sensitive layer of
retina with accommodation being at rest

7.  Total hypermetropia- total amount of refractive error, which
is estimated after complete cycloplegia with atropine,
- It consists of latent and manifest hypermetropia.
 Latent hypermetropia- it is the amount of hypermetropia
about 1D which is normally corrected by the inherent tone of
ciliary muscle.

The degree of latent hyperopia is greater in children and
decrease with age. Revealed after abolishing tone of ciliary
muscle with atropine

8.  Manifest hypermetropia- it is remaining portion of total
hypermetropia that is not corrected by ciliary tone.
- it consists of two components .
 Facultative hypermetropia-the part that is corrected by
the patient’s accommodative effort.
 Absolute- residual part of manifest hypermetropia that is
not corrected by the patient’s accommodative effort.
 Total hyperopia= Latent + manifest (facultative
+absolute )

9. Total hyper
metropia
Manifest
hyper
metropia
Facultative
hyper
metropia
Absolute
hyper
metropia
Latent hyper
metropia

10. Axial(M.C)-decreased AP diameter of
eyeball
Curvatural-flattening of cornea, lens or
both
Index –old age, diabetics under treatment
Positional-posteriorly placed lens
Absence of lens-aphakia

11. Axial hypermetropia –
 Commonest form.
 Total refractive power of the eye is normal but
there is axial shortening of the eye ball.
 About 1mm shortening of the antero-posterior
diameter or the eye results in 3D of
hypermetropia.

12. Curvatural hypermetropia-
 the curvature of cornea lens or both is flatter
than normal.
 There is decrease in the refractive power of the
eye
 About 1mm increase in the radius of curvature
results in 6D of hypermetropia.

13. Index hyperopia – occurs due to change
in refractive index of lens with age or
because of hydration or lens especially in
diabetics.
Positional hyperopia –results from
posteriorly placed lens.
Absence of crystalline lens:- Seen in
aphakia

14. SIMPLE HYPERMETROPIA
 PATHOLOGICAL
 FUNCTIONAL HYPEROPIA

15. Commonest form
Results from normal biological variations in
the development of eyeball
Include axial and curvatural HM
May be hereditary

16. PATHOLOGICAL HYPERMETROPIA
Anomalies lie outside the limits of biological
variation
Acquired hypermetropia
• Decrease curvature of outer lens fibers in old age
• Cortical sclerosis
Positional hypermetropia
Aphakia
Consecutive hypermetropia

17. FUNCTIONAL HYPERMETROPIA
Results from paralysis of accommodation
Seen in patients with 3rd nerve paralysis &
internal ophthalmoplegia

18.  asymptomatic –small amount that can be corrected with
mild accommodative effort , usually in children.
 Asthenopic symptoms- because of the sustained
accommodative effort patient develops asthenopic
symptoms that includes-tiredness of eyes, frontal or
fronto –temporal head ache, watering and mild
photophobia.
 These symptoms are especially associated with near
work

19.  Defective vision with asthenopic symptoms-when
amount of hyperopia is not full corrected by the voluntary
accommodative effort.
 Defective vision- when the error is too high and the
patient do not accommodate, so there is marked
defective vision.

20.  Size of eye ball appears small as a whole.
 Cornea may be slightly smaller than normal.
 Anterior chamber is comparatively shallow.
 Fundus examination –
 Small optic disc, that may look more vascular with ill
defined margins that give false impression of papilitis
called pseudopapillitis.
 BACKGROUND: SHOT- SILK RETINA

21.  Recurrent style, blepharitis,or chalazion may occur
because of repeated rubbing of eye that is done to relief
from aesthnopia.
 Accommodative convergent squint may develop in
children due to excessive use of accommodation.
 Amblyopia may develop due anisometropia, strabismus
or ametropic
 Predisposition to develop primary narrow angle
glaucoma.
Care should be taken while instilling
mydriatics

22. BASIS FOR TREATMENT
No Treatment
Error is small
Asymptomatic
Visual acuity normal
No muscular imbalance

23. SPECTACLES
CONTACT LENS
SURGICAL
OPTICAL TREATMENT

24. Basic principle
Prescribe convex lenses (Plus lenses) so that
rays are brought to focus on the retina
Advantages
 Comfortable
 Easier method
 Less expensive
 Safe idea

27. ADVANTAGES
Cosmetically good
Increased field of view
Less magnification

28.  Refractive surgery is not as effective as in
myopia
TYPES
Laser thermal keratoplasty
Photo refractive keratectomy
LASIK
Photorefrctive keratectomy
Phakic IOL and clear lens extraction