A New Measurement of Anseikonia Tolerance

Study Overview
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Brief Summary
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Population 1: Measure the effect of size glasses from1-9% on stereopsis Population 2: Measure the effect of size glasses from 1-9% on stereopsis in two settings: before and after cataract surgery after dilation of the eye

Detailed Description
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Population 1: 21 eye healthy phakic individuals. Measurements: baseline stereopsis and stereopsis after size glass (1-9%) is added in front of the right eye and in front og the left eye. This measurement provides details on how much size difference a person can endure without impairing stereopsis. Population 2: 11 phakic eye healthy individuals awaiting cataract operation on both eyes. Measurements are the same as population 1 but this study group is also measured after dilating the eyes. This is to see if accommodation affects the measurement. A postoperative measurement six weeks after cataract operation is also performed to examine if cataract operation affects the measurement.

Official Title
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Can we Measure Aniseikonia Tolerance in a Normal Population

Conditions
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Aniseikonia, Anisometropia and Aniseikonia

Intervention / Treatment
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* Diagnostic Test: Measurement of aniseikonia tolerance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: No previous eye history cataract grade <= 1 visual acuity above 0.8 Exclusion Criteria: lack of cooperation amblyopia axial anisometropia ametropia

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 95 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Phakic group<br>21 eyehealthy individuals examined for baseline stereopsis and impact of aniseikonia on stereopsis. An non-invasive measurement. | Diagnostic Test: Measurement of aniseikonia tolerance<br>* Adding sizeglasses of different percent before right and left eye and measure the impact on stereopsis<br>|
| Cataract group<br>11 patients awaiting cataract surgery on both eyes. Measurement of baseline stereopsis and impact of artificial induced aniseikonia on stereopsis. A non invasive measurement that are repeated after dilatation of the eyes and again six weeks after surgery. | Diagnostic Test: Measurement of aniseikonia tolerance<br>* Adding sizeglasses of different percent before right and left eye and measure the impact on stereopsis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Aniseikonia tolerance | How many percent aniseikonia is tolerated before stereopsis is impaired. Measured by first measuring baseline stereopsis and here after adding aniseikonic (size glass) from 1-9% in front of the right and left eye to measure if stereopsis is impaired. If stereopsis is impaired at 4% sizeglas then aniseikonia tolerance is 4%. | baseline | 
| Change of Aniseikonia tolerance after surgery | Measurement of aniseikonia tolerance before and after surgery. Measurement: before and after surgery stereopsis is measured, hereafter aniseikonic glasses (size glass) from 1-9% is added in front of the right and left eye to see if stereopsis is impaired. If stereopsis is impaired with 3% aniseikonic glass then the tolerance is 3%. After surgery the measurement is repeated to examine if the aniseikonia tolerance is the same. | six weeks after surgery |