University of Edinburgh
 

Course: Visual Assessment of Children: The Orthoptist Role

Presented on Wednesday 9 February 2005

Multidisciplinary Functional Vision Assessment

Gillian Coyle, Senior Orthoptist

Functional vision

The ability to use sight in everyday situations

It allows:

  • Access to information
  • Social interaction
  • Mobility

Functional Vision Assessment Team

  • Community Paediatrician
  • Orthoptist
  • Specialist Teacher for Visually Impaired Children
  • Optometrist

Aims

  • To describe the vision available in daily activities
  • To identify the visual difficulties
  • To develop strategies to help overcome the difficulties
  • To maximise the use of residual vision.
  • To enable the child to reach their development and educational potential

How is vision measured?

Traditional

snellen chart

Reduced Visual Acuity 6/18

snellen chart

Resudec visual acuity 6/60

snellen chart

Limitations - optimum conditions

  • Lighting
  • Maximum contrast
  • Important but incomplete assessment of vision

How is vision measured?

Other parameters

  • visual acuity
  • visual field
  • contrast sensitivity
  • colour vision
  • cognitive vision
  • The Assessment

    • CDC or school
    • Assessment
      developmental age
      severity of visual impairment
      associated difficulties

    History

    • Paediatric
    • Ophthalmic
    • Visual
      recognition, orientation, crowding, depth perception, visual memory, perception of movement, visual fatigue
      Dutton et al, Developmental Medicine and Child Neurology 1999, 41: 298-306

    Observed Visual Behaviour

    Detection Vision

    Visual Acuity Tests

    Visual Field Testing

    Visual field defects

    tunnel vision

    • peripheral looss - tunnel vision
    • hemianopia

    Contrast sensitivity test

    • Normal/reduced contrast
    • reduced contrast

    • Normal/defective colour vision
    • colour blindness

    • Cone adaptation test - night blindness

    Eye movements

    • Maintain fixation on an object
    • Follow moving object
    • Look from one object to another
    • Use the eyes together
    • Observation of speed

    Testing eye movements

    Recognition of people

    Visual Assessment of Children: The Orthoptist Role