Management Of Aniseikonia                                                                View Shopping Cart

    Derek Tong, O.D. F.A.A.O.

History

• Chief Complaint
• Ocular & Medical

Refractive Examination

• VA/Refraction/K
• Lensometry

Ocular Health

• Rule Out Dry Eyes
• Rule Out Pathology

Binocular Evaluation

• Rule Out Horizontal/Vertical/Cyclovergence Dysfunctions
• Rule out Accommodative Dysfunction
• Spectacle, Contact Lenses, Prisms, or Vision Therapy?

Contact Lens Consideration

• Difference in keratometry Measurements?
• RGP for Post-Surgical Corneas

Aniseikonia Evaluation

• Subjective Size Comparison
• Rule of Thumb Estimation (1% per 1 Diopter of Aniso)
• Aniseikonia Testing & Quantification (AWAYA, Maddox Rod)
• Trial Framing with Size Lenses

Iseikonic Lens Design

• Lens Material
• Durable, Small Eye-sized Frame
• Base Curve/Center Thickness/Vertex Distance
• Patient Education on Adaptation of 4 Weeks

Follow-Up After 4 weeks of Spectacle Wear

• Any Relief of Initial Symtoms? If Yes, Great!!!
• If No, Redesign Rx Vs Consider Monovision Alternatives.

Monovision Alternatives

• Monovision Contact Lenses/Spectacles
• Partial Occlusion with Bargenter's Foil/Cycloplegia
• Full Occlusion with Occluder Contact Lens/Patch

 

Review Questions:

1. Aniseikonia can be caused by:

a.      Corneal Transplant  

b.      Cataract Surgery

c.       Refractive Surgery

d.      Macular Changes

e.       All of the above

 

2. Aniseikonia is always accompanied by anisometropia:

a.       True

b.       False

 

3. Differential Diagnoses of Aniseikonia may include:

a.        Convergence Insufficiency

b.      Convergence Excess

c.       Accommodative Dysfunction

d.      Hyper-deviation

e.       All of the above

4. All of the following factors can be altered to cause a magnification change except:

a.       Base Curve

b.      Center Thickness

c.       Vertex Thickness

d.      "Front Bevel"

e.       Interpupillary distance

 

5. To design an aniseikonic Rx for a patient who reports a larger image out of the right eye, the ________ eye needs to be magnified.

a.       Right

b.      Left

 

6. Image size through a spectacle lens can be magnified by the following except:

a.       Increasing base curve of a –5.00 DS

b.      Increasing center thickness

c.       Decreasing vertex of a minus lens

d.      Specifying "front Bevel" of a minus lens

e.       Increasing vertex of a plus lens

 

7. The Percentage image size difference can be quantified by the following except:

a.       Rule of Thumb

b.      AWAYA New Aniseikonia Test

c.       Patient's subjective monocular comparison

d.      Trial size lenses and the Miles Test

 

8. If a patient's Rx is OD-5.00 DS, OS –2.00 DS and Ks are OD 43.00 DS, OS 43.00 DS, the anisometropia is __________. If the patient's RX is OD-5.00 DS, OS –2.00 DS and Ks are OD 46.00 DS, OS 43.00 DS, the anisometropia is _____________.

a.       Refractive, Axial

b.      Axial, Refractive

 

Post-Surgical Aniseikonia: Diagnosis & Management

Derek T.Y. Tong, O.D., F.A.A.O.

Derekt_od@hotmail.com

 

Eller Brock Memorial CE Program

American Academy of Optometry Annual Meeting

Orlando, Florida

December 7, 2000

 

 10 Clinical Pearls of Aniseikonia Diagnosis and Management

 

1. Aniseikonia is a binocular phenomenon.
2. Aniseikonia can be induced by refractive surgery, corneal/cataract surgeries, & macula diseases.
3. Aniseikonia can exist when there is little or no anisometropia.
4. to diagnose Aniseikonia, a thorough refractive and binocular evaluation is also required.
5. Treat co-existing binocular conditions with lenses, prisms, & vision therapy as indicated.
6. Prior to designing a size lens Rx, the image size difference needs to be confirmed and quantified.
7. Treat only symptomatic patients.
8. Always consider CL as an option.
9. Use monocular occlusion as a last resort.
10. Set realistic expectation for the patient.

 

Effect of Lens Parameters on Spectacle Magnification:

	High Plus	Low Plus	Low Minus	High Minus
Base Curve	Ý	Ý	Ý	Small
Base Curve	ß	ß	ß	Small
Thickness	Ý	Ý	Ý	Ý
Thickness	ß	ß	ß	ß
Vertex	Ý	Minimal Effect	Minimal Effect
Vertex	ß	Minimal Effect	Minimal Effect

Awaya Aniseikonia Test Book

Aniseikonia Technical Bulletin (pdf)

Aniseikonia And Cyclodeviation Index

 

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