Sarah Smith

Specialist Orthoptist

Bristol Eye Hospital

Learning objectives Overview of orthoptic terminology

Understand different causes and symptoms of squints in children and adults

Understand referral route and management for paediatric orthoptic and ophthalmology services

Review of orthoptic management and appropriate referrals for adult squints

What should I know?

Learning objectives

What is a squint?

How do I test for it?

What symptoms might it cause?

What other tests or investigations may be needed?

When and where should I

refer?

Orthoptics Investigation, diagnosis and management of disorders

of binocular vision

Children and adults

Manage amblyopia (reduced vision in one eye during the critical period)

Investigate and diagnose eye movement disorders

Non surgical diplopia management

Ensure normal development of binocular vision (3D/stereoscopic vision)

Orthoptics - secondary roles Assess vision of children and adults with learning

disabilities/communication disorders

Special schools

Child Development Centres

Functional Vision clinics

Stroke service

‘Virtual’ neuro clinic

Visual Fields

Orthoptics

Investigate, diagnose and

manage disorders of

binocular vision

Is there a squint present?

Is the vision normal?

Is there any double vision?

Are the eye movements

normal?

Is 3D vision (stereopsis)

present?

Paediatric example Parents attend with 8month baby

History of slight intermittent squint

What would you do?

Paediatric example Parent attends with 2yr old

Unusual reflex/white reflex on one in photos over last few weeks

What would you do?

Case study Mum

Unusual reflex left eye seen on photos recently Not noticed a squint Feels vision normal

Fam history F lazy eye ?cause

VA 0.0 0.9

Objects ++ to occlusion of right eye ?slight left ET but nil obvious by reflection/poor fixation left eye Fundus, media, discs normal Refraction RE plano LE +5.0

What is a squint? Tropia –

constant/manifest squint

Phoria –

not always obvious but always present, more apparent on dissociation of eyes

can become manifest at times

…..tropia …..phoria

Hyper

Eso

Hypo

Exo

An easy way to look for a squint

Are the light reflections

symmetrical?

Yes Probably no

manifest squint

No Presume

manifest squint present

Shine a light directly in to the patients eyes

Ideally follow up with a cover test to confirm……

Non-clinical vision testing in children Fixing and following

Visual behaviour

Parental and professional

Objection to occlusion of one eye more than the other

Worth referring on basis of a family history of squint, amblyopia, glasses at an early age etc.

Increased incidence of problems where family history

Paediatric red flags Sudden onset squint

Older child may present with diplopia

Abnormal head posture

Abnormal red reflex

Nystagmus

Divergent squint in a baby <6m old

Sudden reduction in vision

Where to refer? Concern re: vision?

Younger child/baby Refer to HES (BEH or nearest community clinic)

??try a high street optometrist first

Older child Consider advising parent to take child to high street optometrist

first

Complex needs May already be seen at a HUB or in school if ECHP

Where to refer? Concern re: squint?

Younger child/baby

Refer to HES (BEH or nearest community clinic)

Older child

Consider advising parent to take child to high street optometrist first

Complex needs

May already be seen at a HUB or in school if ECHP

Where to refer? Concern re: red reflex?

Refer to Ophthalmologist

Concern re: abnormal funduscopy?

Refer to Ophthalmologist

Red flag referrals should be direct to ophthalmology

Paediatrics - Why does a squint develop?

Causes of squint in children

Refractive

- Long-sightedness

- Short-sightedness

Inherited/family history

Pathology

- Cataract

- Optic nerve hypoplasia

Anatomical/

mechanical

Neurological

Investigations for childhood squint Orthoptics

Assess the vision in each eye separately Measure the size of squint Assess quality of eye movements Assess for presence or absence of binocular functions (3D/stereoscopic

vision) Manage amblyopia treatment if required Exercises if child old enough to carry out

Refraction Optometrist - standard check of health and refractive error of eyes Cycloplegic examination

A large number of childhood squints are associated with refractive error

and can be managed with glasses alone

Further investigations for childhood squint Ophthalmology

Investigate pathology

Dilated fundoscopy/media exam

To discuss/list for squint surgery

To improve cosmesis if glasses do not eliminate squint

To relieve symptoms from decompensated phoria

Order additional investigations

Refer on to other health professionals

Amblyopia Defective visual acuity in one eye (or rarely, both eyes)

which persists after correction of refractive error and removal of any pathological obstacle to vision

Can only develop during the critical period (upto approx. 8yrs old)

Commonly managed by patching/occluding the better eye for a period of time each day

Can also be managing with atropine instilled regularly into the better eye

Referring Agent

GP, Health Visitor, Optometrist

School Health Nurse

Paediatrician

Any child with a suspected/known

ophthalmological*, neurological or

genetic condition, or red flag sign refer to

a Paediatric Ophthalmologist at Bristol

Eye Hospital

Identified Problem

e.g. failed school screen,

obvious squint (strabismus)

poor vision, strong family history

Local community

Orthoptic/Optometry clinic

Orthoptic/Optometry clinic

BEH

Any child

•Examples include nystagmus, cataract, pupils, poor red reflex, amblyogenic ptosis.

•Squints and amblyopia are largely managed in the community and only referred to Bristol Eye Hospital where

appropriate i.e. surgery or suspected pathology

Pathway for Paediatric Orthoptic and Optometry referrals

Nystagmus Constant involuntary wobble of both eyes

Can be sign of pathology/poor visual function

Ocular albinism

Idiopathic

Familial

Final visual acuity outcome largely depends on amplitude of nystagmus

Refer to ophthalmologist

Ptosis Droopy upper eye lid

Usually congenital

May be due to traumatic birth

Can appear less obvious as a child’s face grows

Usually unilateral

Need monitoring if pupil occluded

Refer to ophthalmology of >50% of pupil occluded

Adults - Why does a squint develop?

Causes of squint in adults

Hypertension

Stroke

Diabetes

Anatomical/mechanical

- Thyroid problem

-Facial injury/trauma

- Inflammation/mass

Neurological

Change in a childhood

squint

Adult example Patient attends with history of worsening diplopia over

10day period…

What would you do?

Adult strabismus/diplopia referrals Sudden onset diplopia

Refer via acute/casualty clinic

Intermittent diplopia Consider duration:

Has patient already seen their optometrist?

Refer to orthoptist if prism or exercises may be more appropriate Has patient already seen their optometrist?

Refer to ophthalmology if pathology present or no known cause for diplopia

Patients referred to an ophthalmologist with squint/diplopia should automatically get an orthoptic appointment….

Ocular Motility (eye movements) 6 extra-ocular muscles

Innovated by 3 cranial nerves

Assess where diplopia is present and at its greatest Ask your patient!

Horizontal? Vertical? Combination? Tilted?

Intermittent? When/where is it worse?

Assess how far both eyes move

Establish if monocular or binocular diplopia

Diplopia (double vision) Common complaint in adults with recent onset of squint

Can be temporarily treated by:

Covering or closing one eye

Head posture

Stick-on Prisms

Can only really help with diplopia occurring looking straight ahead

Small prisms can be incorporated into glasses prescription if symptoms stabilise

BoTox

Symptomatic phoria may be treatable with orthoptic exercises and/or prisms

Surgery? Squint surgery is no longer offered to adults in Bristol on NHS (April 2017)

unless patients have diplopia and exceptional funding is in place prior to referral from GP

Refer to Ophthalmologist for surgery

To improve/restore BSV If exercises have been unsuccessful Uncomfortable head posture to maintain BSV

To eliminate or reduce the strength of prism required Diplopia on going even with prisms added Angle too large for prisms to be incorporated

Surgery to improve cosmesis can be undertaken at any age

If an adult never developed normal BSV as a child then surgery will not restore this in adult life

Adult red flags Sudden onset diplopia

Oscillopsia

Summary Take a good history and look at photos! Squints are managed differently according to the age of

onset and aetiology A large number of childhood squints have a refractive

component and do not need surgery Childhood squints are monitored for amblyopia

Symptomatic adult squints are monitored Determine aetiology A number of patients are managed conservatively (by prisms

and/or exercises) A number of patients are kept asymptomatic with temporary

prisms prior to having surgery or during a recovery period

Early intervention is key