Stereopsis and Medical Subspecialty Is there a relationship

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Stereopsis and Medical Subspecialty Is there a
relationship?

• Karen Dacey
• Capt, USAF, MC

March 2006
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Defining stereopsis

• The single perception of a slightly different
  image from each eye which gives the appearance of
  depth of that image

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Three Dimensional Vision-Empirical Horopter
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Is there a Relationship between Medical
Subspecialty and Degree of Stereopsis?

• Is there a statistically significant difference
  in the degree of stereoscopic vision between
• Ophthalmologists and non-ophthalmologic surgeons
  and
• Ophthalmologists and non-surgical physician

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Who was enrolled

• Ophthalmolgists
• Non-ophthalmologic surgeons
• general surgery interns
• general surgery residents
• Non-surgical physicians
• pediatricians
• internists
• radiologists

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Information obtained

• Current specialty
• Other specialty considerations
• Ophthalmic history to include amblyopia,
  strabismus, and ophthalmic surgery
• Near visual acuity
• Stereopsis by Frisby Stereotest
• Defined normal as 40 arc seconds or better

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The Frisby Stereotest
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Advantages Disadvantages

• Ophthalmologist naivete
• Unique test
• Perceive true depth
• No spectacles needed

• Some monocular clues
• Not widely used in clinical settings

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n16
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n 9
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n14
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Ophthalmologists vs. Surgeons
Two sided Fishers exact test, p0.360
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Ophthalmologists vs. Nonsurgeons
Two sided Fishers exact test p0.037
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Spread of the Data Points
Kruskal-Wallis Test, p0.007
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Summary

• All ophthalmologists and most surgeons had normal
  stereovision
• Non-surgical physicians had more abnormal
  stereovision and showed greater variability in
  degree of stereovision
• Suggestive of association between degree of
  stereopsis and medical subspecialty

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Additional Areas of Inquiry

• What degree of stereovision is necessary to
  perform competently as an ophthalmologist?
• Should ophthalmology programs test stereovision
  in applicants?
• How would this information be beneficial to
  medical school advisors?