An overview of the orthoptist practical demonstration the cover test l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 37

An Overview of the Orthoptist Practical Demonstration The Cover Test PowerPoint PPT Presentation

  • Uploaded on
  • Presentation posted in: General

An Overview of the Orthoptist Practical Demonstration The Cover Test. Louise.C.Corp Senior Orthoptist. The Role of the Orthoptist. Assess and Manage: Vision Defects (Amblyopia) Vision Screening Defects of Binocular Single Vision (Squint) Ocular Motility Defects Low Vision Assessment

Download Presentation

An Overview of the Orthoptist Practical Demonstration The Cover Test

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

An overview of the orthoptist practical demonstration the cover test l.jpg

An Overview of the OrthoptistPractical DemonstrationThe Cover Test


Senior Orthoptist

The role of the orthoptist l.jpg

The Role of the Orthoptist

Assess and Manage:

Vision Defects (Amblyopia)

Vision Screening

Defects of Binocular Single Vision (Squint)

Ocular Motility Defects

Low Vision Assessment

Glaucoma Clinics

Vision assessment l.jpg

Vision Assessment

‘Hundreds and thousands’ sweet test

Preferential looking with

Cardiff cards

Slide4 l.jpg

At age 2 years (naming pictures)

Kay single picture

Multiple pictures

At age 3 years (matching tests)



Slide5 l.jpg

Expectations of a baby

  • To be able to fix and follow small toys ( e.g. mobile whilst in their cot), lights.

  • Respond to facial expression ( e.g. confirmed by baby smiling, laughing, following parents face on movement ).

  • Baby will attempt to grasp for small toys whilst fixating on them (e.g play frame over the child whilst laying on their back on the floor)

  • At birth - VA approx 6/240 - Improvement rapid in first 6mths with a slower rate up until 12mths

Managing vision defects l.jpg

Managing Vision Defects

  • AMBLYOPIA – “Lazy Eye” – Reduced vision in one or both eyes

  • Causes – refractive error, squint, stimulus deprivation (ptosis or cataract)


Atropine Penalisation



Optical Penalisation

Vision screening l.jpg

Vision Screening

  • Reception Class (4 - 5yrs)

  • Vision, Check for Squint, Assess BSV, Ocular Motility

  • Pass / Fail Criteria

  • Absentees offered appointment at Community Clinic or re-visit school

  • Referred to: Orthoptic Clinic, Hospital Optician, Consultant, High street Optician

  • 96% coverage 83% passed 5.4% referred to optician 4.8% referred to CRH 1% referred to community clinic as borderline results 4% absent but offered test at community clinic close to home

Defects of binocular single vision squints l.jpg

Defects of Binocular Single VisionSquints

Slide9 l.jpg

There are two types of Strabismus

Slide10 l.jpg

Manifest Strabismus

  • Also known as HETEROTROPIA

  • When one eye focuses on an object, one eye deviates away from the object

  • Squint is caused by failure of two eyes to look at objects in a coordinated manner. Depends on the normal functioning of brain, optic nerve and twelve muscles around our eyes enabling the two images to superimpose on each other and to form a three dimensional image.




Slide11 l.jpg


  • Convergent - one eye deviates nasally (turns inwards) ESOTROPIA

  • Divergent - one eye deviates temporally (turns outwards) EXOTROPIA

Slide12 l.jpg

What type of squint do these patients have?



Reflex at limbus = 45

Reflex at border of pupil = 15

Slide13 l.jpg




  • Epicanthic folds

  • Wide interpupillary distance

  • Short interpupillary distance

Slide14 l.jpg

Essential Infantile Esotropia

Presents within first 6 months


  • Angle large and stable

  • Nystagmus in some cases

  • Normal refraction for age

  • Poor potential for BSV

  • Amblyopia in about 30%

  • Cross fixation

Slide15 l.jpg

Constant Exotropia



  • Presents at birth

  • Disruption of binocular reflexes by

  • acquired lesions, such as cataract

  • Large angle

  • Alternating fixation

  • Normal refraction for age

Consecutive - follows previous surgery for esotropia

Slide16 l.jpg

The effect of glasses

The effect of accommodation

Ocular motility defects l.jpg

Ocular Motility Defects

Abnormal Eye Movements

Slide19 l.jpg

Third Nerve Palsy

  • Ptosis, mydriasis and cycloplegia

  • Abduction in primary position

  • Normal abduction

  • Intorsion on attempted

  • downgaze

  • Limited adduction

  • Limited elevation

  • Limited depression


Slide20 l.jpg

Sixth Nerve Palsy

Straight in primary position due to partial


Limitation of right abduction and

horizontal diplopia

Normal right adduction

Nerve palsies iii iv vi be aware in children l.jpg

NERVE PALSIES (III,IV,VI) Be aware in Children

Present with acute onset Squint

Complaining of Diplopia

Parents notice closing of one eye

Urgent referral

Serious Pathology

More common 6th Nerve Palsy

Slide22 l.jpg

Thyroid Eye Disease

Elevation defect - most common

Abduction defect - less common

Depression defect - uncommon

Adduction defect - rare

Slide23 l.jpg

Right Brown`s Syndrome

Normal elevation in


Straight in primary position

Limited elevation in


Defect to the Superior Oblique Muscle / Tendon

Slide24 l.jpg



Diplopia horizontal vertical l.jpg



Slide26 l.jpg

What to refer to an Orthoptist ??

  • Yes

  • Vision concerns – baby not fixing/following small toy / lights

  • Squint

  • Ocular Movement concerns

  • Poor cooperation of patient to ensure no defects

  • Parental Concern


  • No

  • Family History alone – distant relatives

  • If ? A squint in a child < 4 months old if obvious squint seen then refer if not ask HV to check at 6mths, if still doubtful then refer

Does anyone in the group have a squint l.jpg

Does anyone in the group have a squint?

Let`s find out ???

The cover test l.jpg

The Cover Test

  • “An objective dissociation test to elicit the presence of a manifest or latent deviation. It relies upon the observation of the eyes whilst fixation is maintained and each eye is covered and uncovered in turn”.

  • Firstly, check for a manifest squint before progressing to find a latent squint.

Detection of a manifest squint l.jpg

Detection of a manifest squint

  • Ensure patient is looking straight ahead

  • A light is used initially as the position of corneal reflections may indicate a manifest squint  should be central / symmetrical or both displaced slightly nasal

  • Hold fixation target on a level with patients eyes at a 1/3m and ask them to look at it

  • Introduce occluder in front of one eye and watch for any movement of the other eye

Continued l.jpg


  • If there is no movement, repeat with the occluder in front of the other eye

  • If no movement visible then the patient DOES NOT have a manifest squint at that fixation distance

  • Repeat CT at 6m and far distance if necessary

Possible findings for manifest squint l.jpg

Possible findings for Manifest Squint

Continued33 l.jpg


  • Performed at 1/3m, 6m and far distance

  • Using accommodative/non-accommodative fixation targets

  • With and without glasses

  • With or without any Abnormal Head Posture

  • In 9 positions of gaze if required

Detection of a latent squint l.jpg

Detection of a latent squint

  • Use appropriate accommodative/non-accommodative targets on a level with the patients eyes at 1/3m

  • Introduce occluder in front of one eye

  • Observe for any movement of the eye behind the occluder once it is removed

  • Repeat with other eye

  • If no movement seen, alternate the occluder from eye to eye (make sure binocularity is avoided)

Continued35 l.jpg


  • A movement maybe more obvious as alternate eyes are occluded

  • Size and direction of movement of the occluded eye as it is moved over to the other eye should be noted

  • Speed at which the eye moves back to the normal position as the occluder is completely removed should be noted (rate of recovery) – indicates strength of BSV or vision level

  • Repeat at 6m

Remember l.jpg


  • Position of eyes on appearance

  • Check corneal reflections first

  • Ensure no manifest deviation present first

  • Estimate size of deviation (minimal,slight,mod,mkd) and direction of deviation

  • Fixation targets-light,small picture or toy, 6m picture/object

  • Can the manifest deviation alternate or hold fixation

Thank you l.jpg

Thank you


Orthoptic Dept

Calderdale Royal Hospital

01422 222218

  • Login