University of Edinburgh
 

Functional Assessment of Vision

Presented on 17 January 2013

Functional Vision

Lynn Stewart, Orthoptist, NHS Lanarkshire

My Role

I work as part of the Ophthalmology team at Monklands Hospital. I assess children as part of a multidisciplinary team at the functional vision clinic and low vision clinic

Aims of this Session

  • To understand the difference between a routine diagnostic vision assessment and a functional vision assessment;
  • To have knowledge of a VI child's journey from diagnosis at the ophthalmology clinic to functional vision clinic assessment via a case study;
  • Recognise the importance and value of a functional vision report;
  • Gain experience in use and understand the tests and aids used at functional vision clinics and low vision clinics through a practical session.

Hospital Ophthalmology Team

Orthoptist

Optometrist

Paediatric Ophthalmologist

Diagnose | Qualify | Treat

Orthoptic Assessment

  • Diagnose, monitor and treat vision anomalies;
  • Diagnose and monitor ocular muscle disorders;
  • Diagnose and treat binocular vision problems

Optometric Assessment

  • Dilated refraction of child to assess if refractive error is present;
  • Prescribe spectacles based on this assessment;
  • Child then attends dispensing optometrist in community to chose spectacle frame and have frame fitted.

Ophthalmology Assessment

  • Dilated assessment of eyes to diagnose, treat and manage diseases of the eye;
  • Uses the reports from the Orthoptist and Optometrist along with ophthalmological assessment to form a diagnosis and management plan.

Outcome

  • Parents are given a diagnosis and management plan.
  • Letter is sent to GP.
  • Letter is sent to Referee.
  • Referral to VI service.
  • Child will be monitored by both hospital eye team and VI service.

Referral to the Functional Vision Team

  • By Ophthalmologist, Orthoptist, TVI or Paediatrician
  • Child >3yrs old
  • Aim to see; Pre-school, P3, P7 and S3

Functional Vision Assessment Team

  • Community paediatrician who has child's community /school health record;
  • Orthoptist who has access to child's hospital records;
  • TVI who knows child well and who has records from education re child's use of vision.

QUANTIFY VISION

Tests Used in Functional Vision Assessment

Cardiff Acuity Cards

cardif acuity tests

Keeler Logmar Test

Matching card
Near & distance test

keeler logmar

Kays Picture Test

  • Single
  • Crowded
  • Matching card
  • Near & distance tests

kay tests

Sheridan Gardiner Test

  • Crowded test
  • Single test
  • Matching card
  • Near & distance test

sheridan gardiner

Snellens Test Type

Near & distance test

snellen test

Baillie Lovey Test

Near & distance test

baillie lovey test

Lea Symbols

lea symbols

Hiding Heidi

Near & distance test

hiding heidi

Lea Symbols Contrast Test

lea symbols

Colour Vision Test

  • Colour vision made easy
  • Ishihara
  • PV16

colour vision

Visual Field Assessment

visual field

Cone Adaptation Test

cone adaptation

Case Study

DOB 2/7/08

Diagnosed with albinism shortly after birth and referred to Paediatric Ophthalmologist.

Parents had noticed eyes wobbling.

No family history of albinism or eye problems.

Assessed by Paediatric Ophthalmologist at 4 months

  • Horizontal nystagmus diagnosed
  • Child visually alert
  • No refractive error
  • Referral to VI service made
  • Referral for electrodiagnostic testing made

Follow-up Every 6 Months by Orthoptist

  • Horizontal nystagmus with ? compensatory head posture
  • Fixing and following well
  • Parents feel developing well

Assessed and Monitored by VI Service - Support and advice to parents regarding diagnosis.

Age 2yrs Orthoptic Assessment:

  • Reduced VAR 0.7 0.750 KPS
  • Horizontal manifest nystagmus
  • Decompensating esophoria (tendency to turn in)
  • Dilated refraction - moderate degree of hypermetropic astigmatism
  • Photochromatic glasses prescribed to stimulate VA and control esophoria

Review by Orthoptist and TVI

  • Monitor level of VA
  • Assess how well glasses are worn
  • Assess how well glasses are controlling squint
  • Assess and support child in nursery (TVI)

Referral to FVC and LVC

  • Child using glasses well and adopting a compensatory head posture of chin depression
  • Coping well in nursery
  • Parents pleased with progress
  • TVI concerned re level of VA and referred to FVC and LVC pre-school

Functional Vision Clinic - Purpose of a functional vision assessment is to describe a child's vision ability and vision difficulties

FVC Assessment

Information Provided:

  • Community Paediatrician - "no developmental concerns regarding child"
  • Orthoptist - "child is wearing glasses well and these are controlling squint and clarifying vision"
  • TVI - "child is coping well in nursery as very able child but concern over level of VA and where best suited for primary school"

Parent's Impression of Vision

From Parental Questionnaire:

  • Distance VA worse than near
  • Can follow movement around room
  • Reacts to lights being switched off
  • Photosensitive
  • Problems recognising people further than 2m away
  • Recognises people in photos
  • No problems with clutter
  • No visual field problems
  • Tendency to trip over things and very cautious on uneven floors and going downstairs

Functional Vision Assessment

  • Vision
    - VAR 0.875 VAL 0.875
    - BEO 0.675 (6/30) BEO 0.6N
    - KP crowded
  • Contrast sensitivity
    - 25% contrast at 2m
  • Visual field
    - slightly reduced lower visual field
  • Colour vision
    - normal (CV made easy test)
  • Cone adaptation
    - normal
  • Pupils
    - PERLA-normal
  • Cover test
    - well controlled esotropia
  • Ocular motility
    - horizontal manifest nystagmus with CHP of chin depression

Recommendations

  • Nystagmus is variable thus vision will vary and will decrease with fatigue, stress or anxiety.
  • Compensatory head posture of chin depression may be to dull nystagmus or compensate for reduced lower field.
  • Glasses should be worn at all times.
  • Photochromatic lenses and use of a skip cap will help reduce photophobia.
  • Likely to have problems with reading, tracking and copying from blackboard
  • May have problems with crowding and needs clear, bold well contrasted materials.
  • May have difficulty tracking moving objects (wary of pets).
  • Referral to paediatric low vision aid clinic.
  • Continued support from TVI.
  • Referral to paediatric occupational therapist for assessment of gross motor skills.
  • Will benefit from mobility education in the future Practical Session.