3. 1.HISTORY TAKING
2.VISUAL ACUITY &REFRACTION
3.EVALUATION OF MOTOR STATUS
Inspection of eyes and Head posture
Motor cooperation of eye-
Extraocular movements in 9 gaze positions
Ocular deviation –
Cover, Uncover,Alternate Cover,Prism Bar Cover Tests
Corneal reflection Tests-Hirschberg’s,Krimsky,Bruckner test
Maddox rod , Maddox Wing, Double Maddox Rod
Diagnostic Occlusion
Diplopia Charting,HESS Screen Test
Synaptophore ,Major Amblyoscope
Head tilt test
Convergence,AC/A ratio
Forced Duction test, Forced Generation test
4. •EVALUATION OF SENSORY STATUS
Suppression-
Worth 4 Dot Test
4prism Dioptre Base Out Test
Bagolinis Filter test,Maddox Rod test,After Image test
Binocular perimetry,Haploscopy
Retinal Correspondance-
Afterimage test
Striated Glasses of Bagolini,Major Amblyoscope,
Projection devices
Diplopia Test
Foveo foveal test of Cuppers
Stereopsis
Titmus fly test
Random Dot test, TNO test
LANG stereotest 1 & 2 , LANG 2 Pencil Test
Synaptophore
7. • Related to fatigue or illness?
• More obvious in distance or near fixation?
• H/O defective vision
• Ass w/ Nystagmus or Diplopia
In case of Diplopia
• uniocular/binocular
• Duration
• Type of diplopia- horizontal /cyclovertical
• Direction of gaze in which it occurs
• Whether more marked in distance or near vision
8. • In ACUTE CASES
Precipitating factors like trauma, convulsions ,febrile episode
before onset of squint.
H/O neurological symptoms like loss of consciousness, motor
weakness,slurring of speech,giddiness,hemiparesis,tremors
H/o of previous surgery for squint, occlusion therapy, atropine
penalization
h/o Fever (viral meningitis)
h/o Long standing early morning headache with nausea and
vomiting (raised ICT)
h/o Hearing loss, tinnitus, vertigo
Tingling and numbness (multiple sclerosis)
9. Birth and medical history
• Significant antenatal history
• Maternal infection, any drugs taken during pregnancy
• Any untoward event during delivery
• Length of labour , Birth trauma, forceps, birth asphyxia
• Gestational age
• Birth weight of the child
• Developmental milestones, both physical and mental
• Other associated neurological problems like cerebral palsy,
epilepsy, mental retardation,craniofacial anomalies, behavioural
anomalies, handedness
11. INFANTS AND PREVERBAL CHILDREN (Birth – 14 months)
1.FIXATION PREFERENTIAL TEST(CSM METHOD)
• Central , Steady and Maintained fixation?
• Central foveal fixation
• Steady no nystagmoid movement
• Maintained ability to maintain fixation when converted from
monocular to binocular viewing
• Does he follow target?
• Does he get upset when 1 eye is closed?
2. OPTOKINETIC NYSTAGMUS
• Nystagmus elicited by passing a succession of black and white stripes in
field of vision
• Uses the minimum separable as a measure of visual acuity
12. 3.FORCED CHOICE PREFERENTIAL LOOKING TEST
• attention more attracted by patterned stimulus than homogenous
surface
4.VISUAL EVOKED POTENTIAL
• Light stimulus to retina (checkerboard/stripes/unpatterned flash)
• Recorded by surface electrodes on occiput
• Changes in cortical electrical pattern
13. • Toddlers (14 m to 2 and half years)
1. HUNDRED &THOUSAND SWEET TEST
2. CARDIFF ACUITY TEST
3. DOTT VISUAL ACUITY TEST
4. STYCAR BALLS
14. Preschoolers (2 and half to 5 years)
1. LEA Symbols
2. Allen Picture Card
3. Broken Wheel Test
4. Tumbling E Chart
5. Landolt C Chart
6. Sjogren Hand Test
7. HOTV test
8. Isolated hand figure test
9. Sheridan –Gardiner HOTV test
10. Pictorial vision charts
(crowded KAY picture)
11. Bork candy bead test
15. School going children (5 to 15 years)
1. Tumbling E Chart
2. Landolt C Chart
3. Sjogren hand chart
4. Snellen’s Chart
5. LogMAR chart
18. • Under full cycloplegia (paralysis of ciliary muscles)
esp in childrenneutralize effect of accommodation which masks ref error
• Adequate cycloplegia- 1% cyclopentolate in 60 min
• In darkly pigminted irides or high hypermetropia –Atropine may be required
• <12 m 0.5% atropine
>12 m1% atropine
• Ass with hypermetropia(commonest), astigmatism ,anisometropia, myopia
19. HYPERMETROPIA
In a child with esotropia,esophoria
• Full cycloplegic correction even <2 years
In a child with exotropia .exophoria
• Under correction
ASTIGMATISM
>1.5 D correction given especially after 18 months
20. MYOPIA
In a child with esotropia,esophoria
• Under correction
In a child with exotropia .exophoria
• Full cycloplegic correction
21. GOALS OF STRABISMUS EXAMINATION
1.Establishing a cause for strabismus
2. Diagnosing amblyopia
3.Measuring the deviation
4.Assessing binocular sensory status
22.
23. HEAD POSTURE
• Face turn to right /left horizontal deviation
• Head tilt to right or left shoulder torsional deviation
Chin elevation or depression vertical deviation
• To compensate for deviation
• To permit BSV
• To eliminate diplopia and place eyes in most comfortable position
• Patient position head to reduce need for affected muscle to contract
24. • Head placed in field of action of involved muscle ;eye moves out of field
of action
• In some , head placed in opposite field to increase separation between
diplopic images
• Head tilt to counteract torsional and vertical diplopia
• Chin elevation for weakness of vertically acting muscles
SO palsy Ocular torticollis
IN RSO,
• Chin depression
• Face turn to left
• Head tilt to left shoulder
25. • rule out pseudoptosis -on fixating with affected lid, lids will open
to normal width
• rule out jaw winking Marcus Gunn Phenomenon –whether lid
fissure width changes when jaw is moved or patient chews or
speaks
• rule out retraction syndrome - lid fissure changes when patient
moves eyes to left or right
• rule out pseudostrabismus-epicanthus (semilunar fold of skin
running downwards at side of nose with concavity directed
towards inner canthus)
26. PSEUDOTRABISMUS
• False appearance of squint in the absence of any deviation
• Even when visual axes are parallel, eyes seem to have a squint
27. VISUAL AXIS (line of sight)
• Line passing from fovea to point of fixation
PUPILLARY AXIS
• Line passing through centre of apparent pupil perpendicular to cornea and
meets retina on nasal side of fovea
ANGLE KAPPA
• Formed at the intersection of these 2 axes at centre of pupil
28. • When 1 eye is pointing in (towards the nose)Positive Angle Kappa
• When an eye is pointing out(away from the nose ) Negative Angle Kappa
• Normal fovea lies just temporal to anatomical axis
• light shown in centre of cornea cause reflex on visual axis just nasal to centre
of cornea (+angle kappa =5 degrees)
29. • Large +angle Kappa (in hypermetropia) pseudoexotropia
• Large - angle Kappa (in myopia) pseudoesotropia
33. Uniocular movements
Ductions – only one eye is open, the other covered/closed
tested by asking the patient to follow a target in each direction
of gaze.
Types of ductions:-
34. BINOCULAR MOVEMENTS
Versions:-
Binocular ,simultaneous, conjugate movements in same direction.
both eyes open, attempting to fixate a target &moving in same
direction.
Abduction of one eye accompanied by adduction of other eye is
called conjugate movements.
39. • Abduction is normal when Temporal limbus touches lateral canthus
• Adduction is normal when Nasal 1/3rd cornea crosses nasal punctum
• Inferior ObliquesOn Lateral version, Upwards deviation from horizontal
line passing through centre of pupil
• Superior ObliquesOn Lateral version, Downwards deviation from
horizontal line passing through centre of pupil
• Abduction /adduction/infraduction should have at least 10mm of rotation
• Supraduction of 5-7mm
40. In paresis
• normal ductions observed due to extra innervation called in to
compensate for the paresis
• In versions this is picked up as extra innervation going to yoke
muscle which overacts
1.Primary underaction of involved muscle
2. Sec contracture of unopposed I/L antagonist
3.Sec contracture of yoke muscle
4. sec inhibitional palsy of C/L antagonist
41. • Hering’s law of motor correspondence states that when eyes
move into a gaze direction, simultaneous innervation leads to
yoke muscles having equal force
• Sherrington ‘s law of reciprocal innervation states that increased
innervation and contraction force of a given EOM is accompanied
by reciprocal decrease in innervation and contraction force against
its antagonist
42. In RSO palsy
1. If patient is looking up and left(in direction of I/L antagonist-RIO)
RIO receives reduced innervation as it does not have to overcome the
normal antagonistic action of RSO (SH LAW)
But less innervation to C/l yoke of RIOLSR, giving false impression that LSR is
paretic(HER LAW)
Inhibitional palsy of contralateral antagonist
2. if looking down and right …more innervation required to move right eye to
abduction, C/L Yoke more innervated
over acting LIR
45. HIRSCHBERG TEST
• Initial screening for strabismus
• Uses 1st purkinje image
• Gives rough estimate of angle of a manifest squint
• Useful in young uncooperative patients
• When fixation in deviating eye is poor
Procedure
1.Patient asked to fixate at point light 33cm away
2. Deviation of corneal light reflex from centre of pupil noted
Each mm deviation = 7 degree (1 degree =2 prism diopter approx)
46.
47. KRIMSKY TEST
• Based on Herring Law of equal innervation
• for quick evaluation of angle of strabismus
• Used to centralize corneal reflection in
squinting eye as compared to reflex in fixing eye
• Results expressed in Prism Dioptres
PROCEDURE:
1.Patient asked to fixate on a point light
2. Prisms of increasing power (with apex towards direction of
manifest squint ) placed in front of Non Fixating eye till corneal light
reflex centred in squinting eye
3. Power of the prism required to centre light reflex = amount of
squint in PD
48. BRUCKNER TEST
• Performed using direct ophthalmoscope
• To obtain red reflex simultaneously in both eyes
• Deviated eye has a brighter and lighter reflex than fixing eye
• Helps in diagnosing media opacities, strabismus, refractive errors
49. PREREQUISITES FOR COVER
UNCOVER TEST
1. Ability to fixate target
2. Have central fixation in BE
3. No gross /severe mobility
defects
4. Vision >6/60 in both eyes
Simplest method to Distinguish
between phoria and tropia
50. COVER TEST
• Detects and confirms tropia (manifest)
Procedure:
1.Patient asked to fixate on a point light
2. Normal looking/fixating eye covered with occluder
3. Look for movement of uncovered eye
4. Test to be performed for near (33cm ) and distance (6m)fixation
5. To be done in all gaze fixations
51. • Covering one eye of patient with normal BSV interrupts fusion
• In presence of squint , uncovered eye moves in opposite direction
to take fixation
• In Apparent squint , no movement
• When eye is uncovered It will establish fixation
52. COVER UNCOVER TEST
• Detects and confirms phoria(latent)
• Observe covered eye as cover is removed
• In heterophoria covered eye will deviate towards heterophoric position
• Eg eye will move outward in presence of esophoria
53. ALTERNATE COVER TEST
• Identify TOTAL squint (tropia +phoria)
• More dissociative than cover uncover test
Procedure :
1.Hold occluder over 1 eye for several seconds
(which dissociates BSV)
2.Rapidly move occluder to other eye
3.Observe refixation shift of unoccluded eye, speed and
smoothness of recovery
4. Occluder is shifted back and forth several times
• Both eyes are covered alternatively
• Movement of covered eye noted as cover is changed from 1 eye to other
54. PRISM COVER TEST
• Single prism /prism bar used
• Measures amount of deviation in near or distance fixation in all gaze
positions in prism diopters
• Measures both heteroptropia and heterophoria
• Combines alternate cover tests with prisms
PROCEDURE:
1.Prisms of increasing strength with apex towards deviation placed in front
of 1 eye
BASE OUT –EsO
BASE IN ----ExO
2. Patient asked to fixate with other eye
3.Cover –Uncover test performed till
there is no recovery movement of eye
under cover
55. MADDOX WING
• Based on principle of dissociation by dissimilar objects
• Measures heterophoria for near (33 cm) in PD
• Through 2 slits,
RE sees vertical white arrow and horizontal red arrow
LE sees vertical and horizontal line of numbers
56. PROCEDURE:
1. patient asked to tell
• number on horizontal line which vertical arrow points (gives
amount of Horizontal phoria)
• Number on vertical line at which red arrow is pointing (vertical
phoria measurement)
2.Cyclophoria measures by asking patient to align red arrow with
horizontal line
57. MADDOX ROD
• Consists of multiple cylindrical high
plus lenses of red colour set together
in a metallic disc which converts
appearance of white spot of light into
a red streak
• Measures horizontal and vertical
deviations
• Dissociative –blocks fusion (measures
phoria)
58. PROCEDURE:
1.Patient asked to fix on a point of light in centre of
Maddox tangent scale at distance of 6m
2.Maddox rod is placed in front of 1 eye
• Maddox rod converts point light image into a line
• Thus patient sees a point light with 1 eye and a red
line with other
• Due to dissimilar images of 2 eyes, fusion is broken
and heterophoria becomes manifest
• The no: on Maddox tangent scale where red line
falls will be amount of heterophoria in degrees
• Dissociation b/w point light and redline can be
measured by superimposition of 2 images by prisms
in front of 1 eye with apex towards phoria
59.
60. DOUBLE MADDOX ROD TEST
• Measures Tortional deviations
• Used in cyclodeviations
PROCEDURE:
• Maddox rod is placed in front of each eye (one red,
one white).
• Vertically aligned cylinders produce 2 horizontal lines
• Patient asked whether the 2 lines align exactly with
each other
• The colour of the tilted line is identified by the
patient.
• The corresponding Maddox rod is rotated until the
patient reports that it is vertical.
• The rotation required indicates the size of torsion.
• The two lines will fuse if there is no residual non-
torsional deviation.
61. SYNAPTOPHORE
• Measures angle of deviation
• Assesses retinal correspondance
• Checks for and measures fusion
• Assesses and measures Stereopsis
• Measures ocular alignment subjectively or
with cover testing
• When dissimilar targets are presented to each
eye,patient is asked to superimpose them
• If patient has NRC, horizontal, vertical, and
torsional deviations can be read directly fom
the calibrated scale.
63. • Determine which eye is hypertropic
• 4 possible underacting muscles isolated
• Eg, IN STEP 1 if Right hypertropic means either
• 1. RE Depressors(RSO, RIR) are weak or
• 2. LE Elevators (LIO ,LIR)
64. • In STEP 2 , determine if vertical deviation greater in Ror L gaze
• Eg if its more in Left gaze, draw an oval around the 4 vertically
acting muscles used in left gaze
• Thus it might be either RSO or LSR
65. • STEP 3 involves tilting head to right and then to left
• Head tilt to right stimulates R intorters(RSR, RSO)
L extorters (LIR,LIO) and vice versa
If Vertical deviation increases to Right tilt implicates 4 muscles that act
vertically in right tilt around which oval is drawn
RIGHT SUP OBLIQUE is the only muscle with 3 circles
Around it
66. DIPLOPIA CHARTING
• Patient asked to wear Red and green diplopia charting glasses
• Red glass in front of right eye and green in front of left
• In a semi dark room, he is shown a linear light from a
distance of 4 feet and asked to comment on the images in
primary position and in other positions of gaze
• Patient tells about the position , Brightness and separation
of the 2 images in different fields
67. • Maximum separation in the field of action of paralytic muscle
• If 2 images are joined together No diplopia
• If images are separatedconfirms diplopia
• Maximum separation in the quadrant in which muscle is
restricted
• Image is displaced towards field of action of paralysed muscle
• HOR separation with uncrossed images Esodeviation
• HOR separation with crossed images Exodeviation
• VERT separation with uncrossed images Obliques involved
• VERT separation with crossed imagesVertical recti
68. HESS SCREEN TEST
Principles
1. Dissociation of eyes by Red and green goggles
2. Foveal projection in the presence of normal retinal correspondence
• Hering ‘s and Sherrington’s Law explain the development of muscle
sequelae
Uses
1. Diagnosis of underaction /overaction
2. Mechanical or neurogenic palsy
3.Planning of surgery & post op effects of surgery
4.Monitoring of condition
69. • Electronic Hess screen contains a tangent pattern
(2D projection of a spherical surface )printed onto
a dark grey background
• Red lights that can be individually illuminated by a
control panel indicate cardinal positions of gaze
within a central field (15 degree from primary
position) and a peripheral field (30 degree of
ocular rotation)
• Inner square of 8 dots and outer square of 16 dots
70. PROCEDURE:
1.Patient is seated 50 cm from the screen and wears red
Green goggle(red in front of right eye) & has a green pointer
2. The examiner illuminates each point which is used as point
of fixation
3.This can be seen only with RE ,which becomes fixating eye
4.Patient is asked to superimpose their green light on red
light, so plotting the relative position of the left eye
5. All points are plotted in turn
In Orthophoria, 2 lights should be more or less
superimposed in all 9 positions of gaze
6.Goggles are then reversed (red filter in front of left eye) and
procedure is repeated
7.The relative positions are marked by the examiner on Hess
chart and connected with a straight line
71. LEES SCREEN
• Is a modification of HESS screen
• Uses different method of dissociation
• Red and green complementary colour disso
ciation is replaced with double sided mirror
• Mirror prevents both eyes viewing same scr
een simultaneously although patient percei
ves both images seen by fovea of each eye
as if they are projected straight ahead
72. INTERPRETATION:
1.2 charts are compared
2. Smaller chart eye with paretic muscle(RE)
3. Larger chart eye with overacting yoke
muscle (LE)
4.Smaller chart will show it greatest restriction in
main direction of action of paretic muscle (R LR)
5.Larger chart will show its greatest expansion In
main direction of action of yoke muscel (L MR)
6. Degree of disparity b/w plotted point and
template in any position of gaze gives an
estimate of angle of deviation
73. Forced duction test (FDT) (traction test)
• Simple and most useful method for diagnosing presence of mechanical
restriction of ocular motility
• To assess passive movement of the globe
• To differentiate b/w incomitant squint due to EOM paralysis and that due
to mechanical restriction of ocular movements
FDT +ve (resistance encountered during passive rotation) incomitant squint
due to mechanical restriction
FDT –ve EOM palsy
74. PROCEDURE
1.4% LIDOCAINE
2.Supine position
3.Lids retracted
4. Patient asked to look in the direction of muscle being tested-
the paretic muscle (to relax antagonist )
If RLR possible paretic muscle ,patient asked to look to right
5.Eye held with toothed forceps applied to conjunctiva near the
limbus near insertion of possible mechanically restricted muscle
(on opp side of possibly paretic muscle )
Eg-If LR paresis, apply forceps near MR insertion
6.Eye is moved in the direction of action of muscle ( opp to that in
which mechanical restriction is suspected)
Eg-if LR was possible paretic muscle, eye grasped at medial limbus
and an abduction rotation movement attempted
If eye can be rotated with forceps past voluntary moved limit
presence of paretic muscle
If moves freely Negative
RestrictedPositive
75. To distinguish b/w lateral rectus paralysis & mechanical
restriction involving the medial aspect of the globe, apply the
forceps at 6 and 12 o clock position and move the eye passively
into abduction
• NO RESISTANCE paralysis of lateral rectus muscle
• RESISTANCE mechanical restrictions do exist medially and
contracture of MR ,conjunctica ,tenon’s or MR myositis to be
considered
76. Forced generation test (FGT)
• Performed to differentiate b/w palsy vs Paresis in restrictive pathology
• To calculate potential force in apparently paralysed muscle
• To assess active muscle force which enables eye movement to take place
• Patient is asked to move in a given direction while the observer grasps
eye with an instrument
• If the muscle is paretic, examiner feels less than normal tension
77. DIAGNOSTIC OCCLUSION
• Used to induce full dissociation when its thought that maximum
angle of deviation has not been revealed
• Used in
Intermittent exotropia
To diagnose whether symptoms are due to heterophoria
To differentiate b/w real or apparent limitation of abduction in
children
78. CONVERGENCE
1. Place fixation object at 40 cm in midsagittal plane of patient ‘s head
2. Move the object towards the patient till 1 eye loses fixation and turns
out
This point is Near point of convergence (Normal 8-10 cm or less)
Dominant eye eye that maintains fixation
79. ACCOMMODATIVE CONVERGENCE/ ACCOMODATION RATIO
Amount of convergence (in Prism Dioptres)per unit change in Accomodation(in
Dioptres)
GRADIENT METHOD
• Dividing change in deviation (in PD)by change in lens power
• An accommodative target must be used and working distance held constant
(33cm or 6m)
• Plus or minus lens used to vary accommodative requirement
HETEROPHORIA METHOD
• Distance and near deviations and IPD used
If more exotropic or less eso at near fixation less convergence or low AC/A ratio
If more esotropic or less exo at near fixation high AC/A
In Accomodative eso a diff in eso of 10 PD or more b/w near and distance
fixation high AC/A
81. •EVALUATION OF SENSORY STATUS
Suppression-
Worth 4 Dot Test
4prism Dioptre Base Out Test
Bagolinis Filter test,Maddox Rod test,After Image test
Binocular perimetry
Stereopsis
Titmus fly test
Random Dot test, TNO test
LANG stereotest 1 & 2 , LANG 2 Pencil Test
Synaptophore
Retinal Correspondance-
Afterimage test
Striated Glasses of Bagolini
Major Amblyoscope
Diplopia Test
Foveo foveal test of Cuppers
82. WORTH 4 DOT TEST
• Dissociation test which can be used for both distance and
near fixation
• Differentiates b/w BSV, ARC, Suppression
PROCEDURE:
1.Patient wears red green goggles with red lens in front of
right eye
2.Patient is seated in a dark room
3.He views an illuminated box with 4 circular lights-
2 green lights
1 red light
1 white light
4. Testing distance can be varied to identify size of
suppression scotoma
5.Red light seen through red filter;Green through green
filter;white light by both eyes
White light is only binocular fusion target
83. • 4 dots Normal Retinal Correspondance
In ARC, with Manifest Squint
• 5 dotsEsODEVIATION-Uncrossed (red on right)
• ExODEVIATION-Crossed (red on left)
• 3 green dotsSuppression of Right eye
• 2 red dots Suppression of left eye
84.
85. 4 D PRISM TEST
• Main aim- to prove the presence of normal BSV
• Test done to detect a small central suppression scotoma (or foveal
suppression).
• In patients who have decreased stereopsis but are orthophoric on cover
testing.
• In small to intermediate angle deviations
• The level of dissociation is mild
86. Procedure
1. Instruct the patient to look at a distance target.
2. A 4-BO prism is quickly placed over RE with base out and the examiner
observes the movement of LE.
3. A sudden displacement of the image onto the parafovea will cause re-
fixation if the image is falling on corresponding points on a normal
retina.
4. The test is repeated on LE and the examiner observes the movement
of the RE.
• Strength of prism moves image a little bit in foveal arealeading to
recovery movement in other eye
• no movement will occur if the image has been shifted within a
nonfunctioning (scotomatous) area
87. Interpretations
• When the test is negative, the patient is
considered to be bifoveal.
When the prism is over the right eye, the
left eye moves out and in.
When the prism is over the left eye the
right eye goes out and in.
• There are two responses when there is a
scotoma (microtropia).
There is a scotoma on the right eye if the
prism is over the right eye and there is no
response bilaterally
vice versa for the fellow eye
88. BAGOLINI STRIATED GLASSES
• It detects BSV or suppression
• Evaluation of near and distance retinal corrrespondance
with minimal dissociations
• Each lens of Bagolini Glasses have fine parallel striations
which convert point source of light into a line
PROCEDURE:
1.2 lenses placed at 45 and 135 degrees in front of each
eye respectively
2. Patient asked to fixate a small light source
Testing distance at 6m and 33 cm
3.Each eye perceives an oblique line of light perpendicular
to that perceived by fellow eye
4. Can be used in any desired gaze
89. RESULTS:
• 2 streaks intersect at their centres in form of
oblique cross BSV or ARC of harmonious type
• 2 lines but not forming crossIncomitant squint
with NRC
• Only 1 streak no simultaneous perception and
suppression of other eye
• Small gap in one of the streakCentral
suppression Scotoma
90. TEST FOR FIXATION
Visuoscope or Fixation Star of Ophthalmoscope
• Patient asked to cover 1 eye and fix the star with other eye
• Fixation may be
• CENTRIC
normal on the fovea
• ECCENTRIC
unsteady
Parafoveal
Macular
Paramacular
peripheral
91. SYNAPTOPHORE
• Consists of 2 tubes, having a right angled bend, mounted
on a base
• Each tube has a light source for illumination and a slide
carrier at outer end and a reflecting mirror at right angled
bend and eyepiece of +6.5 D at inner end
USES
• to diagnose anomalies of binocular vision with targets that
are presented to each eye
• To assess deviation and quantify binocular vision(Precise
measurement of angle alpha, Objective and subjective
angle of deviation, Vertical and tortional deviations)
• To detect and quantify area and density of suppression
• To detect ARC
• To measure fusional amplitudes,Stereopsis
92. PROCEDURE:
1. The patient is instructed to place chin on the chin rest.
2. Chin rest and IPD adjusted accordingly.
3. The examiner uses the toggle switches to show the patient the slide
illuminated to right and left eye.
4. As the examiner switches the toggle from the right eye to the left eye it is
representative of cover testing.
5. The eye that is illuminated is the eye that is fixating.
6. The examiner should be able to see the eye movements and be able to
neutralize a horizontal deviation by using the arms at the side of the
machine.
93. • There is a scale near the arms to note the size of deviation.
Neutralizing a vertical deviation requires the use of the R/L Hyper
knobs.
Cyclo deviations are also neutralized using the appropriate knobs
Near deviations can be neutralized by placing a -3.00 sphere trial
lenses in the lens holder in front of the eyepiece. This way, the
patient has to exert 3 D of accommodation to make the objects
clear.
94. • The goal of the examiner is to have the patient fuse the fusion
targets
• Worth’s Grade 1 slides( red slides) simultaneous perception
slides -test subjective and motor angles.
• Grade 2 slides (green) -test motor and sensory fusion.
• Grade 3 slides (yellow) stereoscopic vision slides and -test the
presence of third grade binocularity
95. • Examination of simultaneous perception determination of
angle of strabismus and retinal correspondence assessment
• Fusion amplitude evaluated with use of nearly same pictures,
differing in only small details
• Stereoscopy examined with use of slightly decentred special
pictures, which are projected on disport retinal point, within
Pannum ‘s area, giving the impression of depth and stereoscopy
96. Measurement of Angle of Anomaly:
• denotes the degree of shift in visual direction.
• determined by calculating the difference between the objective and
subjective angles of deviation.
Procedure :
1.The arms of the synaptophore are set at zero.
2. Both the arms of the instrument are moved by the examiner while
alternately flashing the light behind each slide until there is no further
fixation movement of the patient’s eye (alternate cover test).
3.The reading of both the arms is noted at this moment and the sum total of
the reading of both the arms gives the objective angle of anomaly(MOTOR
ANGLE )
4.The subjective angle of anomaly (SENSORY ANGLE )is the angle at which
the visual targets are superimposed, there is no shift and the deviation is
neutralized .
Angle of Anomaly = Objective Angle – Subjective Angle
97. The interpretation of this test is as follows-
•If Subjective Angle = Objective Angle → NRC
•If Subjective Angle < Objective Angle → ARC
•If Angle of Anomaly = Objective Angle →Harmonious ARC
(full sensory adaptation)
•If Angle of Anomaly < Objective Angle →Unharmonious ARC
98. AFTER IMAGE TEST
• In patients who can fixate with foveal area
• To determine ARC and dense suppression
• Highly dissociating orthoptic test
PROCEDURE:
1.In dark room occlude non dominant eye
2. Dominant eye to be stimulated in direction of strabismus
Horizontal beam for horizontal strabismus and vertical beam for vertical
strabismus
3. Non dominant eye getting opposite beam
4. Patient fixates on lighted beam for 10 sec so that fovea is stimulated
5.Patient instructed to close eyes and observe white lines(POSITIVE
AFTER IMAGE) asked to draw position
6.After lights on patient instructed to see blank wall to see black line
(NEGATIVE AFTER IMAGE)
99. If Retinal correspondence is Normal draws a cross
In case of suppression draws 1 line
Esotropic with ARC draws vertical image to left of horizontal
Exotropic with ARC draws vertical image to right of horizontal
100. FOVEO FOVEAL TEST OF CUPPERS
• In patients with eccentric fixation
• An asterisk placed on fovea of deviated eye (under visuoscopic guidance)
• Other eye fixates the light on a Maddox cross or tangent screen
• If one breaks through suppression scotoma of deviated eye, patient can
report position of images
• In NRC Fixation target superimposed on central fixation light of Maddox
crossfovea have common visual direction
• In ARCThe asterisk superimposed on one of the numbers on the
horizontal bar of Maddox scale, number indicating angle of anomaly in
degrees
101. FIELD OF BINOCULAR VISION
• Tested in patients with paralytic squint with some field of single
vision
• Performed on the perimeter using a central chin rest
102. NEUTRAL DENSITY FILTER TEST
• Visual Acuity is measured without and with neutral density filter
placed in front of the eye
• In functional Amblyopia Visual Acuity slightly improves
• In organic amblyopia VA markedly reduced when seen through
the filter
104. TESTS FOR STEREOPSIS
Based on 2 principles
1.Using targets in 2 planes ,constructed so that they stimulate
disparate retinal elements , giving a 3D effect
Eg- Concentric rings, Titmus fly test, TNO test, Random Dot
Stereograms, Polaroid Test, Langs stereo test, Stereoscopic targets
presented haploscopically in Major Amblyposcope
2.Using 3 D targets
Eg-Lang ‘s 2 pencil test
105. QUALITATIVE TESTS FOR STEREOPSIS
1. Lang’s 2 pencil test
2. Synaptophore
QUANTITATIVE TESTS FOR STEREOPSIS
1. Random Dot test
2. TNO test
3. Lang’s stereo test
METHODS USING POLARIZATION
Targets provided as vectographs and images seen by 1 eye is polarized at
90 degree using polarized glasses
1. Titmus Fly test
2. Polaroid test
3. Random dot stereograms
4. TNO test
106. VECTOGRAPHS
• Consists of polaroid material on which 2 targets imprinted so that
they are polarized at 90 degrees with respect to each other
• Patient provided with Polaroid Spectacles so that each target is
seen separately with 2 eyes
• TITMUS STEREO TESTS:
3D polaroid vectograph made of 2 plates in form of a booklet
• 3 PARTS-1.FLY TEST
2.ANIMAL TEST
3.CIRCLE TEST
107. 1.FLY TEST
• Right side of booklet – large housefly
• To test gross stereopsis
• Threshold 3000 sec of arc
• Useful in young children
• If subject asked to pick up one of the wings of fly and
subject sees stereoscopically he will reach above the
plate
• In absence of gross stereopsis fly appears as flat
photograph
108. 2.ANIMAL TEST
• If gross stereopsis present
• Test consists of 3 rows of 5 animals each,1 animal from each row
imaged disparately (threshold 10,200, 400 sec of arc respectively)
• In each row , 1 of the animals correspondingly imaged in 2 eyes printed
heavily black (misleading clue)
• Subject asked which animal stands out
subject with stereopsis will name the disparately imaged animal
subject without stereopsis will name the animal printed black
109. 3.CIRCLE TEST
• Consists of 9 squares, each containing 4circles arranged
in form of lozenge
• Only 1 circle in each square is disparately images at
random threshold (800 to 40 sec of arc)
• If subject has passed other 2 tests , he is asked to PUSH
DOWN the circle that stands out
• When he finds no circle to push or makes a mistake
limit of his stereopsis presumably reached
• Circle no 5 equivalent to 1 sec of arclowest limit of
fine central stereoacuity
110. RANDOM DOT STEREOGRAM TEST
• Devoid of monocular clues
• Patients cannot guess what stereo figure is and where it is located
• Provides truer measurement of stereopsis than Titmus test
111. TNO TEST
• Each test plate consists of a stereogram in which images presented to
each eye have been superimposed and printed in complimentary colours
• Stereograms are viewed through a pair of red and green filters
• Random dot Stereograms have the advantage that they completely
eliminate monocular cues, the patient is required to describe the shape
which can be only seen stereoscopically
112. • TNO Test has 7 plates
• 1st 4 plates are for screening purposes,the disparities are large and ungraded
PLATE I 2 Butterflies of which 1can be seen monocularly, other
only in stereopsis
PLATE II 4 discs, 2 seen monocularly , 2 need stereopsis
PLATE III 4 hidden shapes arranged around centrally placed cross
PLATEIV Suppression test.There are 3 discs,1 seen by right eye,1
by left , 1 seen binocularly
PLATE V-VII test shapes (PAC man Shapes )presented at 6 different
disparities ranging from 15-480 secs of arc
113. LANG ‘S STEREO TEST
• Cards are held at the subject’s reading distance and he or she is asked to
name or point to the pictures
• Displacement of random dots creates the disparity which ranges from 1200
to 550 secs of arc
114. FRISBY STEREO TEST
• Only clinical test based on actual depth , where random
shapes are printed on 3 clear plastic plates of different
thickness
• Doesn’t require any form of dissociation
• Each plate has 4 squares of curved random shapes
• 1 square contains a hidden circle that is printed on the
opposite surface
• Disparities range from 600 to 15 secs of arc
• Care taken that neither the plates nor the patient ‘s head
move during testing as this may provide monocular cues
• If the 1st plate is recognized successfully , then thinner
plates, which give smaller disparities, are presented in a
similar fashion
115. SIMPLE MOTOR TASK TEST
2 PENCIL TEST:
• Detect presence or absence of gross stereopsis (threshold
value 3000-5000 sec of arc)
PROCEDURE:
1. Examiner holds pencil vertically in front of the patient
2. Ask patient to touch its upper tip with the tip of the
pencil in his hand with 1 swift movement from above
3. Patient having stereopsis passes the test with both eyes
open
117. • Examination of
• Associated lid problems
• Ptosis
• Media opacities
• Examination of pupillary reflexes
• Underlying optic nerve or retinal
pathologies
• Examination of fundus in
• Excluding macular pathology
macular scarring
optic disc hypoplasia
retinoblastoma
• Objectively observing torsion of eye
118. REFERENCES
1. Binocular Vision and ocular motility by GUNTER K. VON NOORDEN
2. Pediatric ophthalmology and Strabismus AA0 section 06
3. Practical Orthoptics by T. Keith Lyle
4. Strabismus Simplified by Pradeep Sharma
5. Kanski Clinical Ophthalmology
Notas do Editor
4. Abnormal head posture
6.Associated complaints like photophobia, epiphora, pain, redness.
FAMILY HISTORY= high ametropia,inherited eye or systemic condition
Measured separately for each eye and then together, for both distant and near vision, with and without glasses
Easy in adults and older children
Minimum visible –f/o brightness
Minimum separable- f/o higher cortical centres
Minimum resolvable and minimum recognizable –visual acuity
No fp
Mild prefers fixing with 1 eye..maintains fixation with other thru a blink
Mod holds fixation only upto a blink
Stron cant hold fixation by fellow eye
Pick up sweets at 33 cm VA -6/24
CARDIFF-vanishing optotype
Pics drawn with white band bordered by 2 black bands on neutral grey background
Black Dots on a white background at 25 cm
Stycar balls are graded in size acc to Snellen s acuity
Lea– symbols apple square housecircle
ALLEN -6 pics,horsebird cake hand car telephone
4x4 inch whitebackground
Picture of a car .child has to identify the broken wheel of the car
7 diff levels
Logarithmic progression
Pft snellens
1m from the patient 2 cards one with lines and other blank and then immediately position is flipped and eye movement of patient noted
Ref Error may be responsible for the symptoms and deviation itself
Maximal cycloplegia at 3 hours
Recovery of accommodation at 3 days
Complete bt 10 days
Atropine instilled TID for 3 days not on the day of examination
Discontinue if flushing , restlessness, fever
At birth most babies hypermetropic
2-6 years ↑ in hypermetropia , ↓ in astigmatism
>6 years ↓ in hypermetropia
In a child without squint
Upto 4D not corrected
>4D 2/3rd correction given
<2 years -5D and more to be corrected
2-4 years -3 D and more to be corrected
Older children milder degrees also to be corrected
Duane – co contraction of med and lat recti .retraction of eyeball and narrowing of palpebral fissure on attempted adduction
1-abd.2—add 3, both
bringing the eyes to same level by operating on appropriate extraocular muscles)
1.Mm scale placed on nasal bridge . Patient is asked to close 1 eye.the scale reading bisecting pupil aligned to zero
2,special equipment slot for nose , central line is aligned with midline of the patient
dr seated 33 cm in fron tof patient.left eye covered.
Vertical wire moved till it bisects the pupil(half IPD)
Rotataions arnd Vertical axis –Adduction and abduction
Hor axis- Sursumduction (elevation ) and Deorsumduction
These 4 are cardinal movements of the eye
Rotations arnd AP axis of globe , cycloductions rotate upper pole of cornea nasally (incycloduction)
temporally (excycloduction
)
Contraction overaction
Angle of
If reflex is at the pupillary margin → deviation is 15°
If reflex is seen ½ way between center of pupil and limbus → deviation is 20°
Reflex ½ way between pupillary margin and limbus → deviation is 30°
If reflex seen at limbus → deviation is 45°
If the reflection is deflected nasally, the eye is divergent (i.e. exotropic); if deflected temporally, the eye is convergent (i.e. esotropic).
2 possible muscles are either both intorters or extorters
If pushed …dis adv for recti.. Better for testing obliues
24 hours upto 6 days
R nasal retina contains points corresponding to left temporal retina, stimulation of corresponding poiunts
NrcBoth fovea have common visual direction
corresponding areas of retina stimulated are located equidistantly to the right or left of and above or below the fovea
Harmonious arc –arc fully corresponds to strabismus
Unharmonious –where angle of anomaly less than objective angle of deviation
, and with patients with Monofixation Syndrome.1
Apparatus consists of a pair of plano glasses marked with fine parallel striation of 45 and 135 degrees on the other
Line image is formed at 90 degree of striation
Sp“Power to see 2 dissimilar objects simultaneously”
Fusion Ability of the eyes to produce a composite picture from two similar pictures, each of which is incomplete in a small detail.
It is not superimposition of dissimilar pictures
Stereopsis3D Visual appreciation
Ability to obtain impression of depth by superimposition of two images of the same object, seen from 2 slightly different angle.
In NRC2 angles are equal
In ARC Objective angle> Subjective angle and diff b/w both is called as Angle of Anomaly
ARC harmoniousAngle of anomaly =Objective angle
ARC unharmoniousAngle of Anomaly < Objective angle
Harmonious arc –arc fully corresponds to strabismus
Unharmonious –where angle of anomaly less than objective angle of deviation
Paradoxical – angle of anomaly>obj angle of dev
NRC –patient is fusing
eg Right fovea stimulated with vertical and Left fovea with horizontal bright light
odification -
To determine which parts of the peripheral retina in the deviating eye have acquired a common visual direction with the fovea of the fixating eye,
the patient is asked to guide the Visuoscope until he sees the asterisk superimposed on the central light of the Maddox cross.
The examiner views the fundus when this task is completed and notes the position of the asterisk, which indicates the location of retinal elements having a common visual direction with the fovea of the sound eye.
Reduces the amount of light tranmitted
The test consists of vertical sections seen alternately by each eye as they are seen through in built cylindrical lens elements
Sup oblique palsy excyclotorsion, above the foves
Calculate the angle centre of optic disc to fovea, another line horizontally from the fovea