Guia Basica de vision Binocular, Guías, Proyectos, Investigaciones de Oftalmología

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Binocular Vision Assessment

Daniel E. Neely, MD

Professor of Ophthalmology

Indiana University, Indianapolis USA

Examination Elements

Ocular Motility Exam Form

§ Pertinent Medical History § Current spectacles § Visual Acuity § Stereopsis § Worth 4 Dot § Fixation § IOP § Pupils § Nystagmus § External Exam § Slit-lamp Exam § Versions § Measurements § Pattern § Fundus § Refraction § Assessment/Plan

Stereopsis It is preferable to measure stereopsis prior to any occlusion of the eyes (such as when measuring visual acuity) to prevent “breaking down” of latent strabismus à changing phorias to tropias.

• Titmus Stereo Fly SO-

Stereo Fly 2500 - 1200 arcsec

• Gross stereopsis
• “take both hands and make pinchers…now pinch the fly’s wings”
• Positive : pt. pinches wings up in the air
• Negative : pt. pinches flat against the book

Stereo Butterfly: Alternative to Fly

Wirt Circles 800 - 40 arcsec

• Finely grades stereopsis
• First image has monocular clues
• “push down to circle that is sticking up toward you”
• Tester needs to memorize the sequence or have a key card

Worth 4 Dot

Worth 4-Dot Interpretation From: Gede Pardianto, MD, PhD - Strabismus, binocular vision, 3D vision and visual illusion

Fixation: Equal or Preference?

• OU : Fixates with both eyes at the same time
  • Eyes must be aligned (no strabismus)
• ALT : Fixates equally well with either eye but not simultaneously - Strabismus is present
• OD : Prefers to fixate with the right eye
• OS : Prefers to fixate with the left eye

Motility Diagram 2 RSR RLR RIR

RIO

RMR

RSO

LMR

LIO

LSO

LSR

LIR

LLR

Motility: Over-actions (+1,2,3,4) SR LR IR

IO

MR

SO

MR

IO

SO

SR

IR

LR

+2 + Bilateral, symmetric Inferior Oblique Over-action

Hirschberg Estimation 1 mm=7°=15Δ (prism diopters) Krimsky Test Estimation Techniques Images on this slide © 2016 American Academy of Ophthalmology 2mm=30 PD 4mm=60 PD limbus=90 PD

Prism Cover Test (preferred)

• Simultaneous prism- cover test: - Measures manifest deviation: tropia
• Alternate prism cover test: - Measures maximum deviation: tropia+phoria - Typically the deviation targeted for surgery Images on this slide © 2016 American Academy of Ophthalmology