Hypermetropia Definition, Classification, epidemiology, signs and symptoms, complications, diagnosis and treatment.

1. HYPERMETROPIA
Presented by- Shruti Dagar
Amity University

2. Definition
• The term hyperopia comes from Greek hyper "over" and
ōps "sight"
• When parallel rays of light come to a focus behind the
retina, when accommodation is at rest is called
Hypermetropia or Hyperopia.
• A person who has hyperopia is called hyperope.
• Hyperopia is also called ‘longsightedness’ or
‘farsightedness’.

4. Hypermetropia can be classified on the basis of:
• Anatomical Features (Simple)
• Degree
• Functional
• Pathological and Physiological
Classification

5. Classification by anatomical features:
• Axial Hypermetropia: If antero-posterior diameter of the eye
is less than the normal causes hypermetropia (Normal axial
length is 24mm). 1mm shortening will cause +3D
hypermetropia
• Curvature Hypermetropia: Normal radius of curvature of
cornea is 7.8mm anteriorly and 6.5mm posteriorly. Normal
radius of curvature of lens is 10mm anteriorly and 6mm
posteriorly. If the curvature of cornea and lens is less than the
normal causes hypermetropia. 1mm flattening of curvature of
cornea will cause +6D hypermetropia.

6. • Index Hypermetropia: If refractive index of cornea and lens
is less than the normal causes hypermetropia. Normal
refractive index of cornea is 1.377 and lens is 1.41 at centre
(Nucleus) & 1.386 at periphery (Cortex). This condition may
occur in diabetes under treatment.
• Displacement of lens: If the lens is displaced back ward, it
causes hypermetropia.
• Absence of lens: Absence of crystalline lens causes
hypermetropia. Usually lens is absence of the eye is called
Aphakia. It may be surgical removal or posterior dislocation.

7. Classification by degree of hypermetropia:
Low: +0.25 to +3D
• May have good distance vision and near vision, but may
have eyestrain and headaches with prolonged near work.
Medium: +3.25 to +5D
• Near vision blurred, but good distance vision. M ay have
eyestrain and headaches.
High: >+5D
• Both distance and near vision blurred( near vision is
worse than distance vision.)

8. Classification by the action of accommodation:
Also called Functional Hyperopia caused due to paralysis of
accommodation.
It is of following types:
• Latent Hypermetropia : It is the amount of hypermetropia which is
corrected normally by the normal tone of ciliary muscle. It is more
in young children than in adults. It can be revealed only after
cycloplegic drops are put in the eye.
• Manifest Hypermetropia : The strongest convex lens with which
the patient can still maintain full distance vision 6/6 ,indicates
manifest hypermetropia. Is made up of two components -
Facultative Hypermetropia and Absolute Hypermetropia

9. • Different type of manifest hypermetropia:
• Absolute Hypermetropia: It cannot be overcome by the effort of
accommodation. If the patient can not normally see 6/6 without a lens
then the weakest convex lens that will allow him to read this line
,indicates absolute hypermetropia.
• Facultative Hypermetropia:It is that part of hypermetropia which can
be corrected by the effort of accommodation. Facultative
hypermetropia=Manifest hypermetropia -Absolute hypermetropia.
Total Hypermetropia: It can be find out by abolishing the tone of ciliary
muscle by cycloplegics like atropine.
Total hypermetropia=Latent hypermetropia+Manifest hypermetropia
. (Facultative + Absolute).

10. Pathological Hypermetropia
• This is due to some underlying pathology
• Acquired: Corneal trauma, chalazion, chemical thermal burn, developing
cataract, cyclopegic agents, albinism, aniridia, Lebers congenital amurosis.
A reduction in axial length due to space-occupying lesion within the eye
such as retinal detachment, CSR, orbital tumours, retinal tumour etc.
• Congenital: Micropthalmia, Nanaopthalmia, Cornea plana, lens plana,
sclero cornea, anterior chamber cleavage syndrome, limbal dermoids.
Physiological Hypermetropia
It is normal biological variation. It includes axial and curvatural
hypermetropia. It may be hereditary.

11. Epidemiology
• Age-Related
• Full term infants have mild hypermetropia
• Higher level of astigmatism are associated with moderate to high
hypermetropia
• No gender difference
• Most full-term infants are mildly hyperopic. By age 6-9 months
approximately 4-9% of infants are hyperopic and by age 12
months the prevalence is approximately 3.6%. Infants with
moderate to high hyperopia (greater than +3.50D) are up to 13
times more likely to develop strabismus by age 4 if left
uncorrected.
• Hyperopia is most common in the Hispanic population, next most
common in Native Americans, African Americans, and Pacific
Islanders, and least most common in Asians and Caucasians,
according to a multi-ethnic study of atherosclerosis.

12. Symptoms
• Blurred vision –more for near than for distance.
• Accommodative asthenopia, i.e., Tiredness of eyes
and Frontal or fronto-temporal headache.
• Eyestrain(sore, tired, red, dry, or watery eyes)
• Difficulty reading or performing near tasks
• Vision that seems worse at night or in dim light.
• Squinting of eyes
• Frequent blinking
• Decreased Binocularity
• Eye hand coordination can be decreased.

13. Signs
• Small size of eye ball.
• Small size of cornea.
• Anterior chamber is shallow and the angle is narrow.
• Visual acuity varies with the degree of hypermetropia and
the power of accommodation.
• Divergent squint or Convergent Squint
• Ophthalmoscopically-
a) Optic disc is smaller, hyperaemia with less defined
cup disc ratio.
b) It may show a characteristic appearance which may
resemble optic neuritis or papilloedema.
c) Tortuosity and abnormal branching of blood vessels.

14. Complications:
• Recurrent stye, blepharitis or chalazion may occur due to
repeated rubbing of the eyes to get clear vision.
• Accommodative Convergent squint may develop in
children due to excessive use of accommodation.
• Amblyopia.
• Angle closure glaucoma due to small eye with shallow
anterior chamber and narrow anterior chamber angle.

15. Diagnosis
• The gold standard for visual acuity testing is to use the
Snellen chart using manifest and cycloplegic refraction.
• Subjective refraction can be performed with a visual
acuity chart at far distance and near distance
• Objective refraction can be performed using an auto-
refraction machine or retinoscopy.

16. Treatment:
A)Optical:
1.Glasses: Convex lenses are prescribed after
cycloplegic refraction, particularly children below
10 years.
2.Contact lenses.
B)Surgical:
1.Keratophakia.
2. Epikeratophakia.
3.Keratomileusis.
4.Secondary IOL implantation in Aphakia.:

18. Bibliography
• Brien Holden Vision Institute Modules
• https://eyewiki.aao.org/Hyperopia
• Optometryeducation.blogspot.com