1. Anisometropia & Aniseikonia

2. Objective & Outcome To teach the trainee on
Define Anisometropia & Aniseikonia
List the causes for Anisometropia & Aniseikonia
To list types ofAnisometropia & Aniseikonia
Describe the Vision status in Anisometropia
list few Treatments ofAnisometropia &Aniseikoni

3. Definition
Anisometropia is one of the binocular optical defects. It arises because of difference in refractive error between the two eyes.
Normal
Anisometropia

4. Aetiology 1. Congenital and developmental anisometropia:
This occurs due to differential growth of the two eye ball
2. Acquired anisometropia:
Uniocular aphakia after cataract removal
Traumatic aphakia
Implantation of IOL of wrong power
Keratoplasty in one eye

5. Vision status in Anisometropia
Binocular vision:
In small degree of anisometropia (< 3D)
Uniocular vision:
Refractive error in one eye is of high degree, this eye is suppressed and develops anisometropic amblyopia
Alternate vision:
One eye is emmetropic or hypermetropic and other eye is myopic

6. Clinical Types of Anisometropia
Clinical test
FRIEND test
Worth four dot test
Simple anisometropia
Compound anisometropia
Mixed anisometropia
Simple astigmatic anisometropia
Compound astigmatic anisometropia
Mixed astigmatic anisometropia

7. Power adaptation in Anisometropia
Anisometropia up to 2.5D is well tolerated and that between 2.5D and 4.0D can be tolerated depending upon the individual sensitivity. How ever if it is more than 4.0D it is not tolerated and is a matter of concern .

8. Treatment Medical Contact lens Occlusion therapy Spectacles Surgery
Refractive corneal surgery
Implanting intraocular lens (unilateral aphakia)
Removal of crystalline lens (unilateral high myopia)

9. Aniseikonia Definition
Aniseikonia is an anomaly of binocular vision in which the ocular images perceived at retina are unequal in size or shape or both.
Aniseikonia of > 3% is significant.

10. Aetiology Optical aniseikonia Retinal aniseikonia Cortical aniseikonia
Clinical types:
Symmetrical aniseikonia
Asymmetrical aniseikonia

11. Testing of aniseikonia
Symptoms
Testing of aniseikonia
Space eikonometer
Rule of thumb
Head ache, photophobia
Reading difficulty
Asthenopic symptoms
Vertigo, diplopia
Distorted depth perception
Distorted of binocular vision

12. Treatment Optical aniseikonia: Contact lens Implanting IOL
Refractive corneal surgery
Aniseikonia spectacles
Retinal aniseikonia:
Treatment of retinal disease.
Cortical anisekonia:
Difficult to treat.

13. Thank you