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1. Clinical Evaluation
of
Squint
Anamul Haque
Jr. Optometrist
Ispahani Islamia Eye Institute & Hospital
Date: 14-01-2021

2. Squint Definition
It is a condition in which Only one eye of the visual axes is
directed towards the fixation object, the other eye being
deviated away from the fixation point.

3. Evaluation Steps
1. History
2. Ocular Deviation
3. Ocular Movement
4. Binocular Function
5. Refraction
6. Apattern and v pattern
7. Worth 4 dot test
8. Hess screen

4. History
Medical history
 The child general development.
 Recent illness and treatment.
 Trauma to the head and face.
 Any systemic disease.
Obstetric history
 The mother’s health during pregnancy& delivery.
 The child birth weight.
Birth history
 Pre-natal.
 Post natal.
Family history
 Parental consanguinity.
 Strabismus.
 Refractive error.

5. History continue…
Strabismus in children
 The Direction of strabismus.
 The ageat which it wasfirst noticed.
 Who noticed it.
 Whether the onset wasgradual or sudden.
 Frequency of deviation (constant or intermittent).
 Previous treatment (if any,and the type and results of such treatment).
Strabismus in Adults
 Cosmetic.
 Subjective symptoms.

6. Ocular deviation
1. The cover test & Uncover test.
2. Alternate cover test.
3. Hirschber’s test.
4. Krimsky test.
5. Prism cover test.
6. Maddox rod.
7. Maddox wing.
8. Synoptophore.

7. Cover test & Uncover test
A cover test or cover-uncover test is an objective determination of the presence and amount
of ocular deviation.
 The type of deviation: whether it be eso, exo, hyper, hypo or cyclo tropia.
 The size of the deviation: slight, small, moderate or large.
 Speed to take up fixation: if the eye takes up fixation fast it means there is good
vision in that eye.
 Accommodation on the deviation.
Alternate cover test
Alternate cover test in which both eyes are covers alternatively the movement of the
covered eye is noted as the cover is changed from one eye to the other.
It is more dissociative than cover/uncover test.
Requires
 Pin torch.
 Occluder.
 Target for 33cm and 6m.

9. Hirschberg
Used asan initialscreen for strabismus. This test is a method of estimating the angle of
manifest squint from The position of the corneal reflex in the squint eye.
Normal Exotropia Esotropia

10. Krimsky Test/modified krimsky test
Thi
s test isused to centralizethe corneal reflection in the squinting eyewith
compared to the fixing eye.
Indicationforuse
Thismethodofmeasurementisusedwhen
 Thepatientcannotcooperatewiththeprismcovertestbecauseheistooyoung.
 Mainlyused for non cooperativebaby.
 Verypoorvision

11. Prism Cover Test
In practice this test is most popular and a simple method of measuring the angle of
deviation objectively in various diagnostic position of gaze prisms of increasing
strength with apex towards the deviation are place in front of the eye and the patient is
asked to fixate a target with the other eye.

12. MADDOX ROD
 Use of the Maddox rod provides entirely subjective method of measuring
horizontal, vertical and torsional deviation . (Phoria)
 Dissociation of the eyeis achieved bypresenting aspot light to one eyeand aline
imageto the other eye.

13. MADDOX WING
Instrument by which amount of phoria for near at 33cm can be
measured
Patient sees the two arrows, one vertical to indicate
the horizontal measurement and the other
horizontal indicating the vertical measurement for
33cm with correction.
 Measurements are recorded in prism
dioptres

14. Synoptophore
Uses
 Angleof deviation.
 Assessment of retinal.correspondence or SMP.
 Fusional amplitude.
 Stereopsis.

15. Ocular Movements
The ocular movements are of four types:
 Ductions.monocular eye movement are called ductions
 Versions.Simultaneous movement’s of both eyes in the same direction
are called version
 Vergences.simultaneousmovement of both
eyes in oppositedirectonis called vergence
 Supra nuclear movements.

16. Nine Position Of Gaze
The nine gazes are: straight ahead, left, right, straight up, up and to the left, up and to the
right, straight down, down and to the left, down and to the right.

17. R L
RLR
LMR
RMR
LLR
RSR
LIO
RIO
LSR
RIR
LSO
RSO
LIR
The Diagnostic Positions of Gaze

18. Hess test
The Hess screen test is used for diagnosing ocular motility disorders in patients with normal
sensory status.
Uses
 Diagnosis
 Under action or Over action of EOM.
 Mechanical or Neurogenic palsy.
 A or V pattern
 Planning of surgery and post-op effects of surgery.
 Monitoring of condition.
 Double vision complain
 Nerve palsy

19. BinocularFunction
BSV is the co-ordinated use of the two eyes in order to produce a single unified image in the
dimensions .
Three grades of BSV
Grades.1:Simultaneous Macular Perception(SMP)
This means the ability to see two dissimilar images simultaneously and to superimpose
them.

20. Fusion & Stereopsis
Grade 2, Fusion: This is the ability to see the slightly dissimilar images formed in
each eye and blended them into one.
Grade 3, Stereopsis:
This is the appreciation of the third dimension, allowing the
perception of depth.

21. Worth4 light test
This test can be employed to diagnosed the suppression involving the
peripheral retina. It consists of four circular lights.
 Two green light
 One red light
 One white light.
Results
 4 lights indicatesBSVis normal .
 If the patientsseen only three greenlightshe has righteye suppression.
 Whenthe patientssees only two red lightsit indicatesleft eye suppression.
 5 lights(twored & three green)are seen if diplopiais present.

22. Refraction
Cycloplegia and Retinoscopy
Accurate refraction in children usually requires full Cycloplegia.
Hypermetropia :
 In all forms of esotropia, full correction of hypermetropia is the treatment of
choice.
 When prescribing, 'full correction' means that only the working distance is
allowed for with no subtraction for cycloplegia.
 In esophoria full correction.
 In exophoria or tropia under correction.
Myopia
 In esophoria or tropia under correction.
 In exophoria or tropia full correction or even over correction.