Presentation is loading. Please wait.

Presentation is loading. Please wait.

An Overview of the Orthoptist Practical Demonstration The Cover Test Louise.C.Corp Senior Orthoptist.

Similar presentations


Presentation on theme: "An Overview of the Orthoptist Practical Demonstration The Cover Test Louise.C.Corp Senior Orthoptist."— Presentation transcript:

1 An Overview of the Orthoptist Practical Demonstration The Cover Test Louise.C.Corp Senior Orthoptist

2 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

3 Vision Assessment ‘Hundreds and thousands’ sweet test Preferential looking with Cardiff cards

4 Kay single pictureMultiple pictures Sheridan-GardinerSonksen-Silver At age 3 years (matching tests) At age 2 years (naming pictures)

5 Expectations of a baby To be able to fix and follow small toys ( e.g. mobile whilst in their cot), lights. 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 ). 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) 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 At birth - VA approx 6/240 - Improvement rapid in first 6mths with a slower rate up until 12mths

6 Managing Vision Defects AMBLYOPIA – “Lazy Eye” – Reduced vision in one or both eyes AMBLYOPIA – “Lazy Eye” – Reduced vision in one or both eyes Causes – refractive error, squint, stimulus deprivation (ptosis or cataract) Causes – refractive error, squint, stimulus deprivation (ptosis or cataract) Patches Atropine Penalisation Glasses Blenderm Optical Penalisation

7 Vision Screening Reception Class (4 - 5yrs) Reception Class (4 - 5yrs) Vision, Check for Squint, Assess BSV, Ocular Motility Vision, Check for Squint, Assess BSV, Ocular Motility Pass / Fail Criteria Pass / Fail Criteria Absentees offered appointment at Community Clinic or re-visit school Absentees offered appointment at Community Clinic or re-visit school Referred to: Orthoptic Clinic, Hospital Optician, Consultant, High street Optician 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 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

8 Defects of Binocular Single Vision Squints

9 There are two types of Strabismus

10 Manifest Strabismus Also known as HETEROTROPIA Also known as HETEROTROPIA When one eye focuses on an object, one eye deviates away from the object 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. 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. HORIZONTAL HORIZONTAL VERTICAL VERTICAL TORSIONAL TORSIONAL

11 Horizontal Convergent - one eye deviates nasally (turns inwards) ESOTROPIA Convergent - one eye deviates nasally (turns inwards) ESOTROPIA Divergent - one eye deviates temporally (turns outwards) EXOTROPIA Divergent - one eye deviates temporally (turns outwards) EXOTROPIA

12 Reflex at border of pupil = 15 Reflex at limbus = 45 What type of squint do these patients have? RIGHT CONVERGENT SQUINTLEFT DIVERGENT SQUINT

13 Pseudo-Strabismus Pseudo-Esotropia Epicanthic folds Short interpupillary distance Pseudo-Exotropia Wide interpupillary distance

14 Essential Infantile Esotropia Presents within first 6 months Angle large and stable Cross fixation Normal refraction for age Nystagmus in some cases Poor potential for BSV Amblyopia in about 30% Signs

15 Constant Exotropia Congenital Presents at birth Large angle Disruption of binocular reflexes by acquired lesions, such as cataract Sensory Alternating fixation Normal refraction for age Consecutive - follows previous surgery for esotropia

16 The effect of glassesThe effect of accommodation

17

18 Ocular Motility Defects Abnormal Eye Movements

19 Ptosis, mydriasis and cycloplegia Abduction in primary position Limited depression Limited adduction Normal abduction Limited elevation Intorsion on attempted downgaze Third Nerve Palsy THE PATIENT WILL SUFFER DIPLOPIA

20 Straight in primary position due to partial recovery Limitation of right abduction and horizontal diplopia Normal right adduction Sixth Nerve Palsy

21 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

22 Elevation defect - most common Abduction defect - less common Depression defect - uncommonAdduction defect - rare Thyroid Eye Disease

23 Right Brown`s Syndrome Normal elevation in abduction Straight in primary positionLimited elevation in adduction Defect to the Superior Oblique Muscle / Tendon

24 EYE MOVEMENTS PLOTTED USING THE LEES SCREEN HESS CHART

25 DIPLOPIA HORIZONTAL VERTICAL MAY REQUIRE THE USE OF FRESNEL PRISMS

26 What to refer to an Orthoptist ?? Yes Yes Vision concerns – baby not fixing/following small toy / lights Vision concerns – baby not fixing/following small toy / lights Squint Squint Ocular Movement concerns Ocular Movement concerns Poor cooperation of patient to ensure no defects Poor cooperation of patient to ensure no defects Parental Concern Parental Concern BE CAREFUL!! BE CAREFUL!! No No Family History alone – distant relatives 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 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

27 Does anyone in the group have a squint? Let`s find out ???

28 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”. “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. Firstly, check for a manifest squint before progressing to find a latent squint.

29 Detection of a manifest squint Ensure patient is looking straight ahead 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 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 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 Introduce occluder in front of one eye and watch for any movement of the other eye

30 Continued…………….. If there is no movement, repeat with the occluder in front of the other eye 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 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 Repeat CT at 6m and far distance if necessary

31

32 Possible findings for Manifest Squint

33 Continued………… Performed at 1/3m, 6m and far distance Performed at 1/3m, 6m and far distance Using accommodative/non- accommodative fixation targets Using accommodative/non- accommodative fixation targets With and without glasses With and without glasses With or without any Abnormal Head Posture With or without any Abnormal Head Posture In 9 positions of gaze if required In 9 positions of gaze if required

34 Detection of a latent squint Use appropriate accommodative/non- accommodative targets on a level with the patients eyes at 1/3m Use appropriate accommodative/non- accommodative targets on a level with the patients eyes at 1/3m Introduce occluder in front of one eye Introduce occluder in front of one eye Observe for any movement of the eye behind the occluder once it is removed Observe for any movement of the eye behind the occluder once it is removed Repeat with other eye Repeat with other eye If no movement seen, alternate the occluder from eye to eye (make sure binocularity is avoided) If no movement seen, alternate the occluder from eye to eye (make sure binocularity is avoided)

35 Continued………... A movement maybe more obvious as alternate eyes are occluded 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 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 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 Repeat at 6m

36 Remember……………. Position of eyes on appearance Position of eyes on appearance Check corneal reflections first Check corneal reflections first Ensure no manifest deviation present first Ensure no manifest deviation present first Estimate size of deviation (minimal,slight,mod,mkd) and direction of deviation Estimate size of deviation (minimal,slight,mod,mkd) and direction of deviation Fixation targets-light,small picture or toy, 6m picture/object Fixation targets-light,small picture or toy, 6m picture/object Can the manifest deviation alternate or hold fixation Can the manifest deviation alternate or hold fixation

37 Thank you Louise.C.Corp Orthoptic Dept Calderdale Royal Hospital


Download ppt "An Overview of the Orthoptist Practical Demonstration The Cover Test Louise.C.Corp Senior Orthoptist."

Similar presentations


Ads by Google