Colour and Vision

Sylvie Cringle Orthoptist

Orthoptists – What we do!

Diagnosis and management of disorders of visual

development, binocular vision and ocular motility

Orthoptists – an extended role.

Treatment of patients with

‘Specific Learning

Difficulties’, other reading difficulties and other ‘visual disturbances’

Background

Degree Research Project

Pursuit of interest at Heart of England NHS Trust

Courses/study

BIOS SLD SIG

Reading Difficulties General Learning difficulty

Low intelligence Medical reason

Specific Learning difficulty Dyslexia

Meares Irlen Syndrome (Visual Stress) Other causes:

Physical disabilities such as poor vision or hearing

Lack of knowledge of the English language Lack of exposure to printed material Lack of important pre-reading skills such as the

ability to recognize letters and the ability to attach sounds to letters.

Dyslexia – What is it?

Literally ‘Word Blindness’4% of GB population severely

affectedAffects boys 3 times more than girlsGenetic componentNormal or above average intelligence Difficulty in reading/writing Often not diagnosed and children left

to struggle

Dyslexia – General signs and symptoms

Difficulties with:

Reading, writing and spelling

Sequences

Short term memory

Copying

Mental arithmetic

Directions: Left and Right

Reverses numbers and letters

‘Can’t put ideas onto paper’

Frustration

Lack of confidence

Likes practical not academic subjects

Dislikes reading

Meares Irlen Syndrome (Visual Stress) – Signs and SymptomsSome of the main

symptoms are:

Glare from the page

Headaches when reading

Sore eyes when reading

Movement/blurring of print

Signs include:

Rubbing eyes when reading

Excessive blinking

Tiring/inability to read for long/ poor concentration

Loses place

Dislike of reading

What causes the visual disturbances?Two theories:

Hyper-excitability in Visual Cortex (Pattern Glare)

Disorder of Visual Magnocellular system

Pattern Glare Exaggeration of normal

phenomenon

Visual symptoms when viewing stripes – depends on spatial frequency of the stripes

Spatial frequency of 3 cycles per degree

Uncomfortable patterns = visual distortions

Symptoms alleviated by coloured filters

Visual Magnocellular System

Directs visual attention and eye movements to identify letter order

Visual magnocellular weaknesses may cause visual perceptual instability, hence letter position confusions

Magnocells maximally activated by medium and long wavelengths (yellow)

Assessment of patients with reading difficulties at H of E NHS Trust

Referrals receivedQuestionnaire sent to bring completed

to appointment along with book Orthoptic assessment with additional

testsObservation/assessment of readingIn line with the BIOS SLD clinical

guidelines

Orthoptic Assessment Detailed history

From child as well as parents

Visual Acuity Distance Near With un-crowded

test?

Cover Test

Ocular Movements

Convergence

Accommodation

Fusion

Stereopsis

Measurement

Observation of reading Posture and

movement Eye movements Types of Errors

Dominant eye

Assessment with Coloured Overlays

Management

Appropriate Refractive correction

Orthoptic Exercises or other treatment Convergence Accommodation Fusional reserves Tracking Occulsion

Coloured overlay trial

Practical advice Movement whilst

reading Font type and colour Coloured

pens/paper/computer screen colour

Position in class Liase with class

teacher/SENCO

Colorimetry and Precision Tinted lenses

Case One: ‘The Double Whammy’ 70 year old Male

ARMD

RVA: 6/38 LVA: 6/24

Unable to drive

Struggling to read Magnifier helps Additional symptoms of

movement of print

Orthoptically satisfactory

Chose purple overlay which relieved symptoms

Known Dyslexic

Case Two: Unexplained visual symptoms30 year old female, Librarian

Referred from main clinic Normal Ophthalmological examination Low myopic/astigmatic correction

Symptoms: Uncomfortable in bright light Movement of print Shadowing/’halo’ around print Tired Eyes Frontal Headaches

Case Two: Unexplained visual symptoms

VAs: R and L: 0.3 (6/12) + great discomfort Eyes more comfortable with unilluminated chart

Orthoptically satisfactory, just Slight CI

Chose lime green and mint green overlays

VAs immediately improved with these to:R and L 0.1 (6/7.5) and symptoms decreased.

Case Two: Unexplained visual symptoms

3/12 review RVA: 0.3 (6/12) LVA: 0.4 (6/15) BL RVA: 0.1 (6/7.5)LVA: 0.2 (6/9.5) u/c Keeler

Overlays do help but impractical for her job – used at home for reading

Offered referral for Colorimetry assessment with possibility of precision tinted lenses.

Case Two: Unexplained visual symptoms

On discharge:

RVA: -0.1 (6/4.8) LVA: 0.0 (6/6) BL Read with ease, no discomfort

Symptoms now less Eyes less tired Overlays help with reading at home

Not keen for Precision tinted lenses - cosmetic issue

Case Three: Unexplained reduced VAs 5 year old Male (A) Referred by community optician

Age 3 years 8 months Parents/nursery concerned re Vision

RVA: 1.0 (6/60)LVA: 0.9 (6/48) Kays ‘Surprisingly low VAs’ Straight eyes

Normal Ophthalmological examination Refraction:

R + 7.00 DS L + 7.50 DS Reduced prescription issued: R +5.00 L +5.50

Case Three: Unexplained reduced VAs3/12 Review:

Glasses worn full time R and LVA: 0.65 (6/24-2) Kays Straight eyes

Seen regularly to monitor VA Full prescription of R: +6.00 L: +6.50

issued at annual refraction Cooperation/concentration with VA test

always noted to be poor VAs remained reduced for age Didn’t appear to be ‘overplussed’

Case Three: Unexplained reduced VAs

Age 5 years: R and LVA: 0.5 (6/19) BL (sgls R and LVA 0.7 (6/30)) Still no increase in VA if + lenses decreased. Glasses still worn fulltime ‘A’ comments that VA better cgls. Still no Ophthalmological abnormalities

Age 5 ½ years: Now has small RCS and R amblyopia RVA: 0.62 (6/24-1) LVA: 0.44 (6/15-2) BL

Case Three: Unexplained reduced VAs Electrodiagnostic Tests performed:

VEPs and ERGs entirely normal in each eye So normal, retinal, macular and optic nerve

function in each eye

Parents commented that VA had also been tested and found to be normal Single optotype test used

‘A’ now struggling at school Almost 6 years old Reading difficulties Difficulties seeing whiteboard

Case Three: Unexplained reduced VAs Age 6 years:

RVA: 0.7 (6/30) LVA: 0.3 (6/12) Keeler cr RVA: 0.4 (6/19) LVA: 0.1 (6/7.5) Keeler ucr

Reading assessed: Guesses words Rubs eyes Blinks excessively Difficult for ‘A’ to describe if symptoms present

Coloured Overlay: Appeared to prefer orange and acqua overlays

Case Three: Unexplained reduced VAs

Age 6 ½ years: R amblyopia being treated RVA: 0.54 (6/19-2) LVA: 0.34 (6/12-2) BL RVA: 0.45 (6/15-2) LVA: 0.15 (6/7.5-2) K ucr Doing much better at school Now has extra help at school and home Uses orange overlay Uses bigger print Sits closer to whiteboard Review ongoing

Case Four: Asthenopic Symptoms14 year old girlSymptoms of difficulties including ‘eye

strain’ and headaches when readingCI and Accommodation insufficiency

treated with exercisesSymptoms remained despite

satisfactory Conv and AccommAll symptoms relieved when issued

with coloured overlay

Which patients can be helped?

DyslexiaMeares Irlen Syndrome/Visual StressMigraineAutistic Spectrum DisorderMSParkinson'sOthers?

Vision Tests

Coloured Overlays

Coloured Overlay Spectrum

Coloured lenses

Conclusions.

Reading difficulties and visual symptoms can present at all ages

Be aware of other possible diagnoses Importance of observation Detailed questioning re reading

skills/ability at school Patients may not just have one problem Keep an open mind: ‘Think outside the Box’

Any questions?

Thank You.