This document discusses anisometropia, which is when the total refraction of the two eyes is unequal. It can be congenital or acquired. There are several clinical types including simple, compound, and mixed anisometropia. Symptoms may include eye strain, headaches, and suppression of one eye. Diagnosis involves retinoscopy and tests of binocular vision like the Friend test and Worth's four-dot test. Treatment options include glasses, contact lenses, anisometropic spectacles, and refractive surgery depending on the degree of anisometropia.

1. ANISOMETROPIA
S AL AL M O H AM M A D
B . O P TO M 2 N D Y E AR

2. iNDEX
 I N T R O D U C T I O N
 E T I O L O G Y
 C L I N I C A L T Y P E S
 S Y M P T O M S
 D I A G N O S I S
 T R E AT M E N T

3. iNTRODUCTION
When the total refraction of the two eyes is unequal,
the condition is called ANISOMETROPIA.
The optical state with equal refraction in the two eyes
is termed ISOMETROPIA.
Small degree of anisometropia is of common
occurrence and of not much concern.
A difference of 1D in two eyes causes a 2% difference
in the size of the two retinal images.

4. A difference up to 5% in
retinal images of the two eyes
is well tolerated.
A difference between 2.5 and
4.0 D can be tolerated
depending upon the individual
sensitivity.
If the difference more than 4
D not tolerated and is a
matter concern.

5. ETiOLOGY
A. CONGENITAL and DEVLOPMENTAL
ANISOMETROPIA occurs due to differential growth of
the two eyeballs.
B. ACQUIRED ANISOMETROPIA –
a) Uniocularaphakia after removal of Cataractous
lens.
b) Implantation of IOL of wrong power.
c) Trauma to the eye
d) Keratoplasty in one eye
e) Asymmetric age changes.

6. CLiNiCAL TYPES
A. Simple anisometropia
B. Compound anisometropia
C. Mixed anisometropia
D. Simple astigmatism anisometropia
E. Compound astigmatism anisometropia
F. Fixed astigmatism anisometropia

7. 1- Simple anisometropia
• In this case, one eye is normal (emmetropic)
and the other eye is either myopic ( simple
myopic anisometropia) or hypermetropic (simple
hypermetropic anisometropia)
Normal eye
Myopic eye
Hypermetropic eye
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8. 2- Compound anisometropia
 In this case, both eyes are either hypermetropic
(compound hypermetropic anisometropia) or
myopic (compound myopic anisometropia), but
one eye is having higher refractive error than the
other
Myopic eye
Myopic eye
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9. 3- Mixed Anisometropia
 In this case, one eye is myopic and the other
is Hypermetropia. This is also Antimetropia
Myopic eye
Hyperopic eye
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10. 4- Simple astigmatism anisometropia
• When one eye is normal and the other has
either simple myopic or hypermetropic
astigmatism
Normal eye
Simple myopic
astigmatism
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11. 5- Compound astigmatic anisometropia
• When both eyes are astigmatic but of equal
degree
Simple myopic
astigmatic
Simple myopic
astigmatic
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12. 6- Mixed astigmatic anisometropia
• In this case, one eye has hypermetropic
astigmatism and the other has myopic
astigmatism.
Simple myopic
astigmatic
Simple hyperopic
astigmatic
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13. Status of binocular vision in Anisometropia
• Three possibilities exist as follows:
1. Binocular single vision is present in small degree
of anisometropia (<3 D)
2. Uniocular vision. When refractive error in one eye
is high degree.
3. Alternate vision occurs when one eye is
emmetropic or moderately hypermetropic and the
other myopic, then hypermetropic eye is used for
distant vision and myopic for near.
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14. • Eye strain
• Headache
• Disturbance of binocular vision
• Suppression of one eye
• Difficulty in fixation
• Diplopia occur if the difference exceeds 5%
SYMPTOMS
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15. DiAGNOSIS
1- Retinoscopic examination.
2- testing for state of binocular
vision-
a) Friend test
b) worth’s four-dot test

16. “FRIEND TEST-
1- F, I, N are written in green and R,E,D IN RED
COLOR.
2- It is in corporated in Snellen’s vision box.
3- the patient is to sit a distance of 6 m after
wearing diplopia goggles with red glass in front
of right eye and green in front of the left eye and
asked to read the latters.
F R I E N D
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17. “
Results are interpreted as –
1- Binocular single vision- patient will
read FRIEND at once.
2- Uniocular single vision- patient will
read either F I N or R E D.
3- Alternate vision- the patient will read
F I N at one time and R E D at other
time.
F R I E N D
Binocular single vision
R E D or F I N
Uniocular vision
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18. “
WORTH’s FOUR-DOT TEST-
1- For this test, the patient wear goggles with
red lens in front of the right eye and green
lens in left eye and views a with four lights:
one RED, two GREEN, one WHITE.
2- the patient is made to sit at a distance of 6
m.
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19. “
Interpretation is as below-
1- Normal binocular single vision- if the patient sees
all the four lights in the absence of manifest squint.
2- In abnormal retinal correspondence, the patient
see four light even in the presence of manifest
squint.
3- If the patient sees only two red lights, it indicates
LEFT SUPRESSION.
4- If the patient sees only three green light, indicate
RIGHT SUPRESSION
5- When patient sees the three green lights and two
red lights, alternately, it indicates presence of
ALTERNATE SUPRESSION
6- If the patient sees the five lights (two red and
three green), indicate DIPLOPIA
LEFT SUPRESSION
DIPLOPIA
RIGHT SUPRESSION
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20. “
TREATMENT-
1- GLASS : the corrective spectacles can be tolerated up to a
maximum difference of 4 D, after that, there occurs diplopia.
2- CONTACT LENSES are advised for higher degrees of
anisometropia.
3- ANISOMETROPIC SPECTACLES are an alternate modality for
treatment of anisometropia.
4- OTHER MODALITIES OF TREATMENT -
a) IOL implantation for Uniocular aphakia.
B) Refractive corneal surgery for unilateral myopia ,
astigmatism and Hypermetropia.
C) Phakic refractive lenses are good option for refractive
error of 4-10 D.
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21. Thank You!
Salal mohammad