Behavioral optometry
Department of Optometry and Orthoptics
Medical Faculty
Masaryk University
Brno, Czech Republic
History and development of behavioral
optometry (BEHO)
• BEHO is known as the functional optometry and is widening of
optometric practice which is used for treating of binocular vision
disorders
• BEHO is using many methods of visual therapy (we can place it into
alternative medicine)
• Some methods of BEHO have their origin in orthoptics, but is focused
on patients without strabismus
• The founder of BEHO is A.M. Skeffington
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Optometric Extension Program (OEP)
• Skeffington and E.B. Alexander are founders of so called Optometric
Extension Program in 1928 which contain together 21 steps
• We suppose that low power of some visual functions have negative
effect on vision quality
• OEP is also international organization (www.oepf.org) which deals
with BEHO, post gradual education and edit Journal of Behavioral
Optometry
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Skeffington’s vision model
• Four circle model of vision
• Centering
• Identification
• Anti-gravity
• Language
• There is connection between
vision, brain and body
Source: http://visionhelp.wordpress.com
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I. Binocular and accommodative test
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Eye refraction
• We need maximal plus correction
• Use vertical prism for image dissociation
• Better eye you can make blurry with +0,25 till +0,75 D
• Adapt correction for far (infinity)
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Cover test
• Instruments: Gulden fixation
stick, fixation target, occlusion
• Set up: For near we use fixation
stick, for far isolated optotype
symbol
• Method: Unilateral and
alternating. We can measure
heterophoria with prismatic lens
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Lateral phoria measurement with von Graefe
technique
• Instruments: Phoropter or trial lens with frame, isolated symbol (6/9)
• Set up: You can use rotary Risley prism or prismatic bar, in front of
right eye put 6 prism BD
• Method: Patient see two objects vertically deviated. Use horizontal
prism to move this objects in one line vertically. The same do with
objects in 40 cm
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Vertical phoria measurement with von Graefe
technique
• Instruments: Phoropter or trial lens with frame, isolated symbol (6/9)
• Set up: You can use rotary Risley prism or prismatic bar, in front of left
eye put 12 prism BI and in front of right eye put 6 prism BD
• Method: Patient see two objects vertically deviated. Use vertical
prism to move this objects in one line horizontally. The same do with
objects in 40 cm
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Modified Thorington test: Horizontal and
vertical phoria in near
• Instruments: Light point source, Maddox cylinder, Thorington card
• Set up: Patient is using his correction for far, in 40 cm hold Thorington
card, in center of car there is a hole
• Method: Firstly we measure horizontal phoria and then vertical
phoria (Maddox cylinder is horintaly)
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Modified Thorington test
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AC/A measurement with von Graefe
technique (Thorington card)
• Instruments: Phoropter, trial lenses, trial frame, isolated symbol
• Set up: We introduce isolated letter 40 cm in front of the patient, OS
gets 12 prism BI and OD gets 6 prism BD
• Method: We change horizontal prism in vertical line, after that we
introduce -1 D ODS and again change horizontal position of letters in
vertical line. We expect value 4:1.
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Horizontal vergences testing
• Instruments: Phoropter or prism bar, vertical near reading card
• Set up: We use far correction a test distance vergences, finally we will
use near card
• Method: We increase prism up to blurring, diplopia and recovery in
both direction
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Vertical vergences testing
• Instruments: Phoropter, prism bar, near horizontal reading letter card
• Set up: We use far correction a test distance vergences, finally we will
use near card
• Method: We increase prism up to blurring, diplopia and recovery in
both direction
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Vergence facility
• Instruments: Vergence prism (12 prism BO, 3 prism BI), fixating stick
• Set up: Do with habitual near correction
• Method: We change prism in front of one eye and counting cycles per
minutes (cpm). Patient tries to maintain fusion. We expect 15 cpm
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Negative and positive relative
accommodation
• Instruments: Phoropter or trial frame and lenses, near vertical
reading card
• Set up: Patient wears habitual far correction, near card is holding in
40 cm
• Method: Patient hold sharp and single image. We use plus lenses until
blurry image or diplopia (NRA) and minus lenses until blurry image or
diplopia (PRA)
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Near point of convergence
• Instruments: Light source, fixation target, red-green glasses
• Set up: Patient uses habitual near correction, watching isolated
symbol on fixation target in 40 cm
• Method: The target is slowly moving closer to patient until it is
doubled, continuing in increasing fixating distance to make target
sharp. We note break point and recovery point.
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Stereopsis
• Instruments: Random dot stereotest, polarization glasses
• Set up: Patient watches test through polarization glasses from 40 cm
• Method: We ask which pictures rises from the reading level
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Worth test
• Instruments: Worth test for near with red-green glasses
• Set up: Patient wears red-green glasses and holds Worth test in
distance 33 cm
• Method: We make patient to watch test with right eye and then with
the left eye, finally with both eyes
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Accommodation amplitude – pull away
method
• Instruments: Fixating target, occlusion
• Set up: Patients wears maximal plus distance correction and watches
optotype letter
• Method: We move fixation target far from the patient until patient
will see this clearly. Accommodation amplitude is reciprocal value of
this distance in meters
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Accommodation amplitude – minus lens
method
• Instruments: Phoropter, distance glasses, near fixation target
• Set up: Fixation target is placed in 40 cm and testing is monocular
• Method: We introduce minus lenses monocularly until it is blurry.
Used diopter (plus 2,5 D) shows accommodation amplitude
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Accommodative facility
• Instruments: Fixation target, flipper +/- 2 D
• Set up: Patient wears habitual correction for near, fixation stick in 40
cm, binocular test
• Method: We introduce flipper with plus and minus lenses until
patient announces clear object. We calculate cycles (two change =
one cycle). Expected value is 11 cpm for patient form 13 to 30 years.
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Monocular Estimation Method (MEM)
• Instruments: Habitual correction in near, retinoscope, MEM card,
single spectacle lenses
• Set up: Patient is wearing habitual correction. Examiner is sitting in so
called Harmon distance (typical reading distance, around 40 cm)
• Method: Patient is reading with both eyes. Examiner is looking for the
red reflex movement. When is the movement of red reflex “with” it
means accommodation lag. If the movement is “against” it means
accommodation lead. Expecting values are +0,5 D (lag)
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Fused crossed cylinder
• Instruments: Phoropter with Jackson’s cylinder (minus in 90 degrees)
and grid test
• Set up: Examination in 40 cm, patient wears distance correction
• Method: If the horizontal line is sharper, patient has accommodation
lag, we use +0,25 D until both lines are equally sharp
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Oculomotor test with saccades
• Instruments: One fixation target in green and in red color
• Set up: Patient is sitting against the examiner with fixed head
position. Examiner holds two fixation targets in mid level 20 cm
separated
• Method: Examiner calls color of the stick 5 times and patient has to
fixate. Examiner evaluates movements of the head, of the body and
ability and exactness of the saccades
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Oculomotor test for pursuits
• Instruments: Fixation stick or target
• Set up: Examiner is sitting in front of patient and gives no information
about the eye movement. Fixation target is in 40 cm
• Method: Examiner is moving with fixation stick in front of patient
noticing pursuits and evaluating movements of the head, of the body
and ability and exactness of the pursuits
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II. Analysis and classification of the cases
• Page 50
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A – Graphic analysis
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Graphic analysis – plus/minus
• Plus:
• There is possible to define area of the clear simple binocular vision,
determine AC/A ratio, phorias, PRA, NRA, is possible to use Sheard’s criterion
(opposite size of fusion should be twice higher than phoria)
• Minus:
• This method ignore accommodation facility, fusion ability, fixation disparity,
MEM
• There is no possibility to classify disorders of the binocular vision (e.g.
accommodation excess, insufficiency)
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B – Analytical attitude
• Developed thanks to EOP and contains
• 21 examinations
• Comparing measured values with the norm
• Sorting data into groups
• Identification and classification of the clinical status
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Analytical attitude – EOP norms
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Analytical attitude – pros/contras
• Pros:
• Concept 1: Status of vision system is going worse during aging
• Concept 2: Vision disorders can be reduced with exercises, prismatic
correction etc.
• Contras:
• EOP is difficult system which needs specific preparing (special education for
proffesionals)
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C – Morgan’s analysis
• This program was firstly introduced in 1944
• This analysis shows that on defected value from binocular vision
system is not significant. Significant is when we detect more than one
defected value from specific group of vision parameters
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Morgan’s analysis – excepted values
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Morgan’s analysis – grouping of values
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Morgan’s analysis – pros/contras
• Pros:
One abnormal parameter does not meter
• Contras:
• This analysis missed evaluation of some parameters: accommodation ability,
fusion ability, fixation disparity, MEM, oculomotor parameters
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D – Analysis of fixation disparity
• Fixation disparity (FD) is small fixation deviation during binocular
viewing. Usually it is only a few arc minutes
• For FD analysis we can use e.g. Mallet test, Wesson card or
Disparometer
• Some authors thinks that FD is the best method for solving binocular
problems
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Fixation disparity – Mallett test
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Fixation disparity analysis – pros/contras
• Pros:
• Data are gained from binocular vision
• Contras:
• Testing of FD brings no information about accommodation and oculomotor
disorders
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E – Integral analytical attitude
• Connects previous systems together and tries to eliminate their
disadvantages
• EOP: Visual system is worsening during ageing
• Anomaly parameters analysis and their grouping according Morgan
• Examination of FD during binocular conditions
• Examination of accommodation and vergence facility, MEM, retinoscopy
• Contains 3 basic steps:
• Comparing individual and normative data
• Grouping of parameters and norms
• Identification of syndrom
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Integral analytical attitude - grouping
• Data are grouped into six categories according to visual function,
which is tested
1. Positive fusion vergence tests
2. Negative fusion vergence tests
3. Accommodation system evaluation
4. Vertical fusion vergence evaluation
5. Oculomotor evaluation
6. Motoric evaluation and interaction
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1 - Positive fusion vergence tests
• Positive fusion vergence (PFV) – soft testing
• PFV – step testing
• PFV – vergence facility
• NRA
• Binocular accommodative facility with plus lens
• NPC
• MEM
• Fused crossed cylinder
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Positive fusion vergence (PFV) – soft/smooth
testing
• Using phoropter or Risley prism softly growing base out
• Patient tries to see clearly target for far or near
• Measuring is stopped when patient see blurry or doubled target
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PFV – step testing
• Using prism bar
• Results can be different in comparing with soft testing PFV, especially
in children
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PFV – vergence facility
• Using 40 cm distance (= 2,5 D)
• Patient holds vertical test
• We introduce 12 prism BO and 3 prism BI
• If the patient has diplopia probably is not able to use PFV
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NRA
• Patient fixates near target
• Binocularly we introduce +0,25 D
• Patient tries to maintain clear target
• If we change accommodation we either change convergence, so we
can expect diplopia
• We can do this test monocularly. If monocular NRA is higher problem
is in PFV
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Binocular accommodative facility with plus
lens
• We test convergence when we change accommodation
• We introduce +2 D binocularly
• When patient has AC/A ratio 5:1, should use with +2 D binocularly 10
prism PFV
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NPC
• Position of the NPC is influenced by many factors: accommodative
convergence, proximal convergence and PFV
• Small value of NPC shows pathological value of PFV
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MEM
• Using in binocular conditions
• Normal values are +0,25 to +0,5 D (lag)
• In patients with exophoria and low PFV we can expect low values of
MEM (to zero)
• Some patients with exophoria can use accommodation and
accommodation convergence to decrease the exophoria
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Fused crossed cylinder
• On phoropter place Jackson’s crossed cylinders with minus axis into
90 degrees and use grid test
• Examination distance is 40 cm
• If the horizontal line is clear, patient has accommodation lag, we
introduce +0,25 D lens until both lines are equal
• Or we accept the last plus lens before patient see vertical line clearly
• Expected values +0,5 accommodation lag for non-presbyopes
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1 - Evaluation of PFV tests
• In patients with exophoria we usually measure lower values of these
parameters (PFV)
• MEM and fused crossed cylinder shows usually higher values due to
increased accommodation and convergence
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2 - Negative fusion vergence tests
• Negative fusion vergence (NFV) – soft testing
• NFV – step testing
• NFV – vergence facility
• PRA
• Binocular accommodative facility with minus lens
• MEM
• Fused crossed cylinder
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Negative fusion vergence (NFV) – soft testing
• Using phoropter or Risley prism adding prism BI until blurry or
diplopia
• We expect decrease of accommodation due to decrease of vergence
accommodation
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NFV – step testing
• We use prism bars with BI prism
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NFV – vergence facility
• We use 40 cm vertical test introducing 12 prism BO and 3 prism BI
• If it is doubled it shows problem with NFV
• If the target is blurry during measurement it shows that
accommodative vergence helps to fusional vergence to keep single
image
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PRA
• Patient watch near target with distance correction. We introduce -
0.25 D
• Accommodation is accompanied with increase of accommodative
convergence and depend on AC/A ratio
• Patient has to decrease NFV value to maintain simple binocular vision
• If we cover one eye we can reveal if the problem is in PRA or in NFV
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Binocular accommodative facility with minus
lens
• We test change of convergence during the change of accommodation
• During patient watching near object we introduce -2 D
• These diopters start increase of accommodation convergence, which
depends on AC/A ration
• The result can shows inadequate value NFV or disability to stimulate
accommodation
• If we cover one eye and picture is still blurry it shows disorder of
accommodation
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MEM
• If we have low value of NFV we usually measure higher values MEM
(more than 0.5 D)
• Patient try accommodate to maintain simple binocular image
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Fusion crossed cylinder
• If we have low NFV values we usually measure high MEM values
(more than 0.5 D)
• Patient is trying to accommodate to maintain single binocular image
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2 - Evaluation of NFV tests
• Patients with esophoria shows lower NFV values
• MEM and fusion crossed cylinder shows contrarily higher values
(lead, e.g. -0.5 D)
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3 - Accommodation system evaluation
• Monocular accommodation amplitude
• Monocular accommodation facility with plus and minus lenses
• MEM retinoscopy
• Fusion crossed cylinder
• Binocular accommodation facility
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3 - Accommodation system evaluation -
introduction
• Accommodation is evaluated successfully during monocular
conditions (is eliminated contamination of accommodation with
binocular disorders)
• Test for PFV and NFV shows status of accommodation influenced by
binocular system
• For example if the patient has low PRA value the cause should be in
the insufficient accommodation or in esophoria
• We can confirm insufficient accommodation after revealing
pathological NFV
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Monocular accommodation amplitude
• Low monocular accommodation values shows accommodation
insufficiency in pre-presbyopes
• Patient will low values of accommodation in all test when using
accommodation
• Contrarily problem with relaxation of accommodation is not revealed
if proper accommodation is measured
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Monocular accommodation facility
• While changing plus and minus lenses we change accommodation
• We usually use +/- 2 D lenses
• We calculate cycles per minute (cpm)
• We can get 4 different results (next slide)
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Monocular accommodation ability with +/lenses
- results
1. Adequate result in comparison with norms
2. Inadequate result with plus and minus lenses. It can influence other
tests (e.g. PRA, NRA)
3. Adequate result with minus lenses and inadequate result with plus
lenses shows high accommodation, spasm or excess
accommodation
4. Adequate result with plus lenses and inadequate result with minus
lenses shows problems with stimulation of accommodation. It could
be accommodation insufficiency or ill-sustained accommodation
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MEM retinoscopy
• MEM enables evaluate patient’s accommodation response
• Examination distance is 40 cm, expected values are +0.25 to +0.5 D
• Higher values shows accommodation lag, usually followed with low
PRA
• Lower values (e.g. minus values) contrarily shows accommodative
spasm or excess, usually followed with low NRA
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Fusion crossed cylinder
• Higher values (more than +0.5 D) shows accommodation lag or
accommodation insufficiency
• Lower values (less than 0 D) shows accommodation lead usually
connected with accommodation spasm or excess
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Binocular accommodation facility
• If the patient has normal binocular finding (phoria, PFV, NFV) test
results (NRA, PRA, low cpm of accommodation facility) shows
accommodation anomaly and problem with interaction between
accommodation and vergence
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3 - Accommodation system evaluation – final
evaluation
• Accommodation is better to check monocularly
• The most sensitive are test which tests accommodation during time,
e.g. accommodation facility
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4 - Vertical fusion vergence evaluation
• Supravergence and infravergence
• Fixation disparity
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Supravergence and infravergence
• Right infravergence is compensation mechanism of fusional vergence
for right hyperdeviation
• Right supravergence is measured with prism BD in front of OD until
patient will see objects doubled
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Vertical fixation disparity
• Is the prism which reduces associated heterophoria in vertical
direction
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5 - Oculomotor evaluation
• Fixation status
• Saccades subjective evaluation according the scale
• Developmental eye movement test (DEM test)
• Subjective evaluation of pursuits according the scale
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Fixation status
• Patient should fixate minimally 10 seconds
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Saccades subjective evaluation according the
scale
• Using oculomotoric test NSUCO (Northeastern State University
College of Optometry)
• NSCUCO test:
• Patient should fixate 2 objects in 40 cm. Both objects are moved 10 cm from
medial line
• Evaluation:
• Fixation ability (max 5 points during 5 movements)
• Fixation exactness (max 5 points without fixation error)
• Head and body movement (max 5 points without movement)
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NSUCO test of saccades - scoring
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NSUCO test saccades – minimal criterion
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Developmental eye test (DEM test)
• If the patient has problem with NSUCO test we use DEM test
• Patient has to read symbols form test as quick as possible without
errors
• 80 letters vertically 80 horizontally. We calculate time. The result is
ration between time for horizontal and vertical direction
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DEM test – picture and table
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Subjective evaluation of pursuits according
the scale
• We use NSUCO test
• Examiner holds fixation object in 40 cm and makes circles with
diameter around 20 cm clockwise twice and than twice
counterclockwise
• Result:
• Fixation ability (max 5 points during 5 movements)
• Fixation exactness (max 5 points without fixation error)
• Head and body movement (max 5 points without movement)
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NSUCO test – score for pursuits
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NSUCO test – criterion for pursuits
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6 - Motoric evaluation and interaction
• Test for phoria values and direction
• Fixation disparity
• AC/A ratio
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Test for phoria values and direction
• You can use Maddox test, Thorington test or Graefe technique
• You should measure direction and value of the phoria for distance
and near
• Distance phoria is usually caused by error of tonic vergence
• Near phoria depends on AC/A ration
• Phoria is compensated with fusion vergences
• For exophoria compensator is PFV
• For esophoria NFV
• For right hyperdeviation right infravergence
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Fixation disparity
• The main advantage is that testing is realized during binocular
conditions
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AC/A ratio
• AC/A ratio shows relationship between distance and near deviation
• AC/A influences solving of binocular vision disorder
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Visual disorders classification and syndrome
identification
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Binocular anomalies – classification
• Duan’s classification
• Convergence insufficiency
• Convergence excess
• Divergence insufficiency
• Divergence excess
• This classification is not suitable because there are no groups with
same deviation for far and near
• Wick shows classification with groups according vergences (distance
phoria) and AC/A ratio
• Nine possible groups are connected with vertical anomalies and
accommodative anomalies according Duke-Elder and Abrams (p.73)
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Binocular anomalies - table
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Category 1: Binocular disorders with low AC/A
1. Ortophoria at distance – convergence insufficiency
2. Exophoria at distance – convergence insufficiency
3. Esophoria at distance – divergence insufficiency
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1 - Ortophoria at distance – convergence
insufficiency
• Patient has normal tonic vergence and low AC/A
• The result is intermediate or high exophoria at near
• Symptoms: Asthenopia, headaches, blurry vision and diplopia,
symptoms are worse on afternoon
• Signs: Near exophoria, reduced PFV at near, reduced vergence facility
with prism base out, intermittent near suppression, low AC/A, fail
accommodation facility with +2 D, low MEM and FCC (fusion crossed
cylinder), low NRA and fixation disparity
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2 - Exophoria at distance – convergence
insufficiency
• Low tonic vergence and low AC/A
• Symptoms: Asthenopia, headache, blurry vision, diplopia, symptoms
are worse in the evening, impossible to concentrate
• Signs: Near phoria is greater than distance phoria, reduced PFV on far
and near, reduced vergence facility far and near with prism base out,
intermittent near suppression, prolonged NPC, low AC/A, impossible
to pass through test of accommodation facility with +2 D, low MEM
and FCC, low NRA, exo-disparity for far and near.
92
3 - Esophoria at distance – divergence
insufficiency
• Patient has esophoria for distance (high tonic vergence) and low
AC/A, far phoria is greater than near phoria
• Symptoms: Distance asthenopia, intermittent blurry vision and
diplopia, symptoms worsening in the evening
• Signs: Distance esophoria is greater than near, reduced distance NFV,
reduced vergence facility with prism base in, distance eso-fixation
disparity
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Category 2: Binocular disorders with normal
AC/A
1. Ortophoria at distance – fusional vergence dysfunction
2. Exophoria at distance – basic exophoria
3. Esophoria at distance – basic esophoria
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1 - Ortophoria at distance – fusional vergence
dysfunction
• Patient has distance and near orthophoria and decreased fusion
reserves
• Symptoms: Asthenopia, blurry vision, symptoms are worsening during
the day, eye itching and lacrimation, problem with concentration,
slow reading
• Signs: Distance and near orthophoria, reduced PFV and NFV, low PRA
and NRA, low binocular accommodation with +/- lenses, normal
monocular accommodation facility
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2 - Exophoria at distance – basic exophoria
• Normal AC/A means the same value of exophoria for distance and
near
• Symptoms: Asthenopia during distance and near working,
intermittent blurring or diplopia for far and near, symptoms are
worsening during the day
• Signs: The same exophoria for far and near, reduced PFV for far and
near, reduced distance and near vergence facility with prism BO, low
NRA, low binocular accommodation facility with plus lenses, low
MEM and FCC, exo-disparity, type III of exo-disparity curve
96
3 - Esophoria at distance – basic esophoria
• Patient has esophoria for far and near, high tonic vergence and
normal AC/A
• Symptoms: Asthenopia for far and near, intermittent blurring and
diplopia for far and near, symptoms are worsening during the day
• Signs: Distance and near esophoria, reduced NFV at far and near,
reduced vergence facility at far and near with prism BI, low PRA, low
binocular accommodation facility with minus lenses, high MEM and
FCC, eso-fixation disparity, type II fixation disparity curve
97
Category 3: Binocular disorders with high
AC/A
1. Ortophoria at distance – convergence excess
2. Esophoria at distance – convergence excess
3. Exophoria at distance – divergence excess
98
1 - Ortophoria at distance – convergence
excess
• Patient has distance orthophoria and high AC/A ratio
• Symptoms: Asthenopia, intermittent blurring and diplopia, symptoms
are worsening during the day, itching and burning, problems with
concentration, slow reading and text understanding
• Signs: Near esophoria, reduced near NFV, reduced near vergence
facility with prism base in, low PRA, fail binocular accommodation
facility with minus lenses, high MEM, eso-fixation disparity for near
99
2 - Esophoria at distance – convergence
excess
• Patient has low or intermediate distance esophoria (high tonic
vergence) and high AC/A. Near esophoria is higher than distance
esophoria
• Symptoms: Asthenopia, intermittent blurring and diplopia, worsening
during the day, itching and burning, inability to concentrate, decrease
of text understanding
• Signs: Near esophoria is higher than distance esophoria, reduced
distance and near NFV, reduced distance and near vergence facility
with prism BI, low PRA, low binocular accommodation facility with
minus lenses, high MEM, eso fixation disparity at far and near
100
3 - Exophoria at distance – divergence excess
• Patient has low distance exophoria (low tonic vergence) and high
AC/A ratio. Distance exophoria is greater than near exophoria
• Symptoms: Eyes are in exo position, uncomfortable in near, children
try to close one eye
• Signs: Greater distance exophoria than near, high AC/A ratio,
suppression for distance, normal NPC, limited NFV, adequate PFV,
problems with fusion, normal near stereopsis
101
Category 4: Vertical anomalies
• Usually are classified right or left hyperphoria
• Symptoms: Blurry vision, headaches, asthenopia, diplopia, dizziness in
car, problems with concentration during reading
• Signs: Anomaly head position, hyperphoria, reduced PFV and NFV,
reduced vergence facility at distance and near with prism BI and BO,
VFV is usually low or contrarily high
102
Category 5: Accommodative anomalies
1. Accommodation insufficiency
2. Ill-sustained accommodation
3. Accommodation excess
4. Inertia of accommodation
103
1 - Accommodation insufficiency
• Symptoms: Similar like in presbyopia, blurry vision at near and
discomfort, fatigue, problems with near working concentration
• Signs: Low accommodation amplitude, low PRA, problem with mono
and binocular accommodative facility with minus lenses, near
esophoria, high MEM and FCC
104
2- Ill-sustained accommodation
• Symptoms: Similar like in accommodation insufficiency, blurry vision,
discomfort in near working, disability to concentrate at near
• Signs: Normal accommodation amplitude in first measurement, in
repeated measurements is accommodative amplitude decreasing,
low PRA, low mono and binocular accommodation facility with minus
lenses (decreasing in time), near esophoria, high MEM and FCC
105
3 - Accommodation excess
• Symptoms: Asthenopia and headache at near work, intermittent
blurring while near gaze
• Signs: Changing visual acuity, low value of against the rule
astigmatism, low MEM and FCC, low NRA, near and sometimes also
distance esophoria, low mono and binocular accommodation facility
with plus lenses
106
4 - Inertia of accommodation
• Symptoms: Problems with clear vision from distance to near and vice
versa, asthenopia at near work, difficulties with concentration and
intermittent blurring during near working
• Signs: Difficulties with mono and binocular accommodation facility
with plus and minus lenses, low PRA and NRA
107
Category 6: Ocular motor anomalies
• According to Scheimann (2002) are ocular motor anomalies
connected with fixation, saccades and pursuits
• Symptoms: Rapid head movements, words and row skipping, slow
reading, problems with reading of tables, difficulties during sport
activities
• Signs: DEM score and NSUCO test score are worse than 15th percentil
108
Accommodative and non-strabismic binocular
vision disorders - table
109
Cases analysis with systematical approach
• During analysis of patients we can use algorithm, which can be
described by the scheme
• We know typical symptoms and signs which are typical for binocular
vision disorders
• It is important to evaluate so called non-functional etiology, which is
not directly relate to binocular vision
• We have typical anamnesis questions for evaluation symptoms and
signs of patients
110
Symptoms and signs following binocular
disorders
• Excessive blinking
• Eye pain and headache during near working
• Disability to concentrate for near working
• Intermittent diplopia
• Letters or row of letters skipping
• Sensitivity to light
• Blurry vision for far and near
• Low near distance
• One eye closing
• Slow reading
• Bad reading text understanding
• Head tilting
111
Non – functional etiology
• External eye evaluation (malformation)
• Pupillary reaction evaluation (direct, indirect)
• Swinging flashlight test
• Color vision
• Ophthalmoscopy
• Versions
• Cover test for distance, near and different gazing directions
• Visual field – confrontation test
112
Questions from anamnesis
• When sings appears?
• Have you been sick recently?
• Have you taken some medical pills recently?
• Have you had change in your taste recently?
• Have you had some changes in sleeping recently?
• Have you changed your weight recently?
• Do you have swellings?
• Are problems worse morning or in the evening?
• Do you feel sick?
• Do you have headaches?
• Do you have weakness of muscles?
113
114
115
Case 1
• Distance orthophoria
• Near esophoria
• Normal NFV and AC/A
• Disorder of the MAF and BAF
shows probably on
accommodation exces
116
Case 2
• Distance orthophoria
• 2 prism near esophoria
• PFV distance 6/10/6
• NFV distance X/5/2
• AC/A norm
• PFV near 4/8/6
• NFV near 6/10/4
• Low NFV and PFV shows fusion
vergence disorder
117
III. General therapeutic attitude
• Page 93
118
Difficulties definition and continuous therapy
• Questionnaires:
• Convergence Insufficiency Symptom Survey (CISS)
• College of Optometrists in Vision Development Quality of Life Outcomes
Assessment (COVD-QOL)
119
Convergence Insufficiency Symptom Survey
(CISS)
• Each answer has 0 to 4 points
• All answers with 0 points means
without symptoms, 60 points
means all symptoms
• The norm is less than 16 point
for children bellow 17 years and
below 21 points for older than
18 years
120
College of Optometrists in Vision Development Quality of Life
Outcomes Assessment (COVD-QOL)
• Scale from 0 to 4 points,
maximum 76 points
• Score up to 20 points shows
significant symptoms
• Questionnaire is possible to use
before and after visual therapy
121
General therapeutic sequence in nonstrabismic
binocular anomalies
• Therapeutic sequence is influenced by AC/A and fusional vergence
1. Optical correction of refractive error
2. Using addition
3. Prism
4. Occlusion
5. Visual therapy
6. Surgery
122
1- Optical correction of refractive error –
Refraction limits
• Significant refractive error which can cause symptoms is:
• Hyperopia +1.5 D and more
• Myopia -1 D and more
• Astigmatism 1 D and more
• Anisometropia 1 D and more sphere or cylinder
123
1- Optical correction of refractive error –
Results of uncorrected refractive error
• Undercorrection or overcorrection can lead to:
• Accommodative dysfunctions
• High phoria or exhausting of the fusion reserve
• Eye lateral disbalance disturb fusion
• Decreased fusion makes the image blurry
124
1- Optical correction of refractive error –
Cycloplegic refraction 1
• Usually we use objective and subjective refractive values
• In case of esophoria we expect latent hyperopia so we recommend
cycloplegia
• For children over 3 years we use 1 gtt 0.5% of cyclopethanolate
hydrochlorid with repetition every 5 minutes. After 40 minutes we are
able to measure latent refraction
125
1- Optical correction of refractive error –
Cycloplegic refraction 2
• In cycloplegia we reveal tonus of ciliary muscle
• After cycloplegic refraction we should finally subtract 0.75 D, i.e. less
in plus lenses, and more in minus lenses
126
1- Optical correction of refractive error –
Small refractive errors
• E.g. +0.25Dsph. Comb. -0.5Dcyl. Ax. 90
• So called small refractive errors can influenced patient’s comfort
• We should completely measure simple binocular vision and according
the result we should decide pro or contra correction
• E.g. If the patient has small PFV with exophoria in near is
recommended to correct such u error
127
1- Optical correction of refractive error –
Anisometropia and aniseikonia
• Clinically significant is anisometropia 1 D
• Generally we try to correct anisometropia maximally (sharp image is
important for the fusion)
• Some patient are sensitive for increasing of correction, so we should
reduce this correction
• So called Knapp’s law recommend use glasses for axial error and
contacts for systemic error
• Increased anisometropia correction increases prism during peripheral
gaze and disturb horizontal and vertical fusion vergence
128
2 – Using addition
• If we add plus lenses 1 D in patient with AC/A 12:1 we can decrease
esophoria with 12 prism
• Contrarily in patient with far exophoria if we add minus lenses 1 D we
can decrease exophoria
• AC/A value show us how many diopters we should add
129
2 – Using addition – add plus lenses
130
2 – Using addition – add minus lenses
131
2 – Using addition – effect of plus lenses
132
2 – Using addition – effect of minus lenses
133
2 – Using addition – when use the addition
• Plus lenses
• Convergence excess
• Basic esophoria
• Accommodative insufficiency
• Ill-sustained accommodation
• Minus lenses
• High exophoria
• Divergence exces
134
3 - Prism
• Bellow we mention situation when the prism can be used
1. Horizontal relieving prism
2. Vertical relieving prism
3. Prism as the support for beginning of visual therapy
4. Usage prism during the visual therapy
5. Usage prism after visual therapy
135
3 – Prism: 1 – Horizontal relieving prism
• We use prism usually for decreasing fusion vergence or increasing of
lower fusion vergence
• Prisms are effective in high tonic vergence or in esophoria for distance
with normal or low AC/A
• Prism can be used during the visual therapy or without the visual
therapy
136
3 – Prism: 1 – Horizontal relieving prism Results
of studies
• Worrell ed al. (1971) found prism preference in low distance
esophorie
• Stavis et al. (2002) identified asthenopic symptoms in patient with 2
weak wearing prism correction
• Scheiman et al. (2005) found difference between children with
convergence insufficiency corrected with prism and with placebo
• O´Leary and Evans (2006) found in 58 patients with associated
heterophoria from 0.5 to 2 prism no increasing of reading ability.
Increasing was found in group with associated heterophoria form 2.5
to 3 prism
137
3 – Prism: 1 – Horizontal relieving prism Fixation
disparity analysis
• This method is the most suitable for prescribing of relieving prism
• Prism value can be chosen according to
• Amount of associated phoria
• In case of steep fixation disparity curvature
• Center of fixation disparity curve symmetry
• In case of middle steep curve
• Flat part of fixation disparity curve
• We try to shift flat part of curve to axis ypsilon
138
Center of fixation disparity curve symmetry
(in case of middle steep curve)
139
Flat part of fixation disparity curve We
try to shift flat part of curve to axis y
140
3 – Prism: 1 – Horizontal relieving prism Sheard’s
criterion
• Sheard (1930) concluded that we need doubled value of opposite
fusion vergence to eliminate the phoria
• We can you formula bellow:
141
3 – Prism: 1 – Horizontal relieving prism Percival’s
criterion
• This criterion is more effective in esophoria
142
3 – Prism: 1 – Horizontal relieving prism Recommended
application algorithm
• Primary we use prism in high
distance tonic vergence
(esophoria)
• In visual therapy if it is
ineffective
143
3 – Prism: 2 – Vertical relieving prism
• London and Wick (1987) found important effect of vertical prism on
horizontal deviation
• Primary we should correct vertical deviation
• The most reliable method for measuring vertical prism is fixation
disparity method or we can use Sheard’s criterion
144
3 – Prism: 3 - Prism as the support for
beginning of visual therapy
• Prism can be used as compensatory aid in high phoria or intermittent
tropia during visual therapy
• For training we use prism base out in patient with low NFV
145
3 – Prism: 4 - Usage prism during the visual
therapy
• If we have patient with bad compliance or visual therapy can not be
used we can use prism
146
3 – Prism: 5 - Usage prism after visual therapy
• If the patient has problems with binocular vision after the visual
therapy we can prescribe prismatic correction
147
4 - Occlusion
• This is typical therapy in strabismus – amblyopia, eccentric fixation,
suppression with anomaly retinal correspondence
• We can use occlusion also in heterophoria with anisometropic
amblyopia
• Studies shows effect of amblyopia therapy if is used 2 hours per day
plus 1 hour of visual therapy in near (amblyopia less than 0.25)
• We can also use partial occlusion, e.g. in patients with high distance
exotropia OD and low at near. On upper part of OD’s visual field we
put partial occlusion
148
5 – Visual therapy - usage
• Many patients with binocular disorders and disorders of
accommodation are not preferred for spectacle lenses and prism
therapy
• For spectacle lens and prism therapy are recommended patients with
accommodative insufficiency, divergence insufficiency, convergence
excess, basic esophoria or vertical phoria
• Visual therapy is recommended in patients with convergence
insufficiency, divergence excess, fusion vergence dysfunction, basic
exophoria, accommodative excess or insufficiency, or motor
dysfunction
149
5 – Visual therapy – scientific background and
effectiveness
• Visual therapy is effective in patients with accommodative, motor and
non-strabismic binocular disorders
• Visual therapy reduces symptoms, increases accommodation
amplitude and facility, eliminates accommodative spasm, improves
near point of convergence, increases fusion vergence and facility,
reduces suppression, increases stereopsis and exactness of the
saccades and pursuits, improve fixation stability
150
5 – Visual therapy – when recommend the
visual therapy?
1. Patient’s age and intelligence
2. Data analysis
3. Patient’s status definition and prognosis
4. Financial and economic view
5. Patient’s motivation
6. Relationship between symptoms and optometric findings
7. Time of particular therapy courses
151
5 – Visual therapy: 1 - Patient’s age and
intelligence
• Visual therapy is not suitable for very young children
• Visual therapy needs patient’s concentration and attention
• Visual therapy is usually recommended from 6 years in patients with
heterophoria and from 3 years for patient’s with strabismus and
amblyopia.
152
5 – Visual therapy: 2 - Data analysis
• Very important is data analysis and their grouping
• Prisms are usable for patients with divergence insufficiency and
vertical heterophoria. They also helps in esophoria or exophoria
• Spectacle lenses are suitable for accommodative disorders –
accommodation insufficiency, excess, esophoria or divergence excess
153
5 – Visual therapy: 3 - Patient’s status
definition and prognosis
• Visual therapy solve all binocular disorders without divergence
insufficiency
• Hoffman et al. (1973) showed success with visual therapy in 87 % of
patients (n=80)
• Gallaway and Scheiman (1997) tested 83 patients with convergence
excess. After visual therapy 84 % of patients had eliminated
symptoms with increase of NFV
• Study form Wold et al. (1978) showed statistical important difference
between saccades and pursuits in 100 patients before and after visual
therapy
154
5 – Visual therapy: 4 - Financial and economic
view
• Sometimes motivated and intelligent patients is not guarantee of
non-problem therapy
• It depends also on financial possibilities of patient and their parents
• In some countries is possible to use some healthy insurance during
the visual therapy
155
5 – Visual therapy: 5 - Patient’s motivation
• Patient’s motivation can increase but also decrease the prognosis
during the visual therapy
• If there is bad motivation and cooperation with children we
recommend to ask patient to motivate children at home before the
therapy
156
5 – Visual therapy: 6 - Relationship between
symptoms and optometric findings
• Generally the vision therapy is functional in non-strabismic,
accommodative and motor disorders
• If we define precisely the problem, we can recommend specific
solution
• E.g. Patient has headache with diplopia during reading. We found
receded near point of convergence, near exophoria and reduced PFV
• On the other side there are no subjective symptoms (e.g. children
with learning difficulties). Children have problems for example with
accommodation avoiding reading and writing but have no symptoms
157
5 – Visual therapy: 7 - Time of particular
therapy courses
• During the diagnosis we can reveal possible alternation to visual
therapy, e.g. prism or spectacle correction
• If the alternative solution is quicker than visual therapy we can chose
rather this solution
• Generally we can say that long-lasting visual therapy can be consider
as the risk factor
158
6 – Surgery of the eye muscles
• Eye muscle surgery is not common solution of non-strabismic
binocular disorders
• The conservative solution is usually unsuccessful if we measure
phoria around 30 prism
• According Herman (1981) around 1 % from 1200 patients after
orthoptics therapy after 10 years have still problems with vision and
have to undergo surgery intervention
159
IV. Primary care of binocular vision,
accommodation and monocular problems
• Page 118
160
IV. Primary care of binocular vision,
accommodation and monocular problems -
introduction
• Primary care in optometry means responsibility for visual and
connected systemic disorder of the patient
• Optometrist should be educated not only in optometry but also in
health care
• Table on the next page shows primary care in optometry and
heterophoria
161
162
Table continues on this page
low AC/A normal AC/A high AC/A
163
IV. Primary care of binocular vision,
accommodation and monocular problems – an
overview
1. General diagnosis
2. Refractive error assessment
3. Non-strabismic binocular disorder assessment
4. Accommodative disorder assessment
5. Primary analysis of accommodative and non-strabismic disorder –
an overview
6. General therapeutic guidelines – case histories
164
1 - General diagnosis
• For finding the diagnosis you can use some questionnaires, e.g.
Convergence Insufficiency Symptom Survey (CISS), Vision Quality
Scale (VQS). This questionnaires will help you chose binocular vision
tests
• CISS questionnaire will help you define the value of symptoms in
convergence insufficiency and intermittent exotropia
165
1 - General diagnosis – CISS questionnaire
• Use from 0 to 4 points, maximal
count is 60 points which means
totally symptomatic patient
166
1 - General diagnosis – Vision Function Scale
(VFS)
• VSF is general tool for assessment of quality of binocular vision
developed by McKeon (1997)
• This tool measures vision in patients with intermittent exotropia
• This questionnaire distinguishes patients with and without
asthenopia
• Patient chooses one answer from 6 possible answers (from 0 to 6
points). These points are after that converted into percents
• Result lower than 71 % in patient older 8 years means symptomatic
patient
167
1 - General diagnosis – Vision Function Scale
(VFS) - Questionnaire
168
2 - Refractive error assessment
• Recommended procedure:
• Use optotype’s row 0.6
• Patient has covered OD, add +0.25 D on OS, if it not decreases visus use it. You
can do the same procedure on other eye
• Use JCC
• Use vertical dissociating prism and add 0.25 D on better seeing eye. The goal
is release the accommodation
• Remove dissociating prism and add minus until patient see 1.0
• Do the stereo test
• Test visual acuity. If it is not better than 1.0 you can use minus lenses
169
3 - Non-strabismic binocular disorder
assessment
• The phoria value and direction assessment
• AC/A calculation
• Vergence evaluation
• Near point of convergence
• Fixation disparity
170
3 - Non-strabismic binocular disorder assessment The
phoria value and direction assessment
• Cover test is an objective method to reveal the value and direction of
phoria
• We expect 1 prism distance exophoria (tonic vergence) with SD 1
prism and 3 prism near exophoria with SD 3 prism
171
3 - Non-strabismic binocular disorder
assessment - AC/A calculation
• AC/A value often influences the
chose of therapeutic method,
e.g. near esophoria with high
AC/A ratio enables successfully
use plus addition
• Expected values of AC/A are 6:1
with SD 2 prism
172
3 - Non-strabismic binocular disorder
assessment - Vergence evaluation
• Gall et al. (1998) recommends to use 3 prism BI and 12 prism BO to
distinguish symptomatic patients
• As a fixation target we usually use vertical column of letters size 0.6
173
3 - Non-strabismic binocular disorder
assessment - Near point of convergence
• We determine convergence amplitude
• It is recommended to examine twice. Ones with accommodative
target and ones with light point with red filter in front of one eye
174
3 - Non-strabismic binocular disorder
assessment – Fixation disparity
• The main advantage of this test is performing under real conditions
(association test, fusion)
• This method is very suitable for vertical phoria measurement
175
4 - Accommodative disorder assessment -
overview
• Accommodative amplitude
determination (Hofstetter’s rule)
• Accommodative facility
determination
• Monocular estimation method
(MEM)
176
4 - Accommodative disorder assessment –
Accommodation amplitude
• We usually use push-up method
• We can use in front of both eyes minus 4 D which make measurement
more exact
• Patient has to read letters until it is clear
• Disadvantage: There is not subjective equal letters size. Letters with
size 0.6 pro 40 cm will be bigger if they are read from 10 cm
(accommodation overestimation)
177
4 - Accommodative disorder assessment –
Accommodation facility
• Yothers et al. (2002) recommends 2 diopters flipper form 40 cm to
distinguish symptomatic patients
• We usually do this test binocularly (BAF). If it is not possible we can
do it monocularly
• It is recommended to use binocular polarized test to control
suppression (each eye sees different part of the test)
178
4 - Accommodative disorder assessment –
Accommodation facility - Table
• Recommended test distance:
• 145 % of accommodation
amplitude in cm
• Recommended flipper power:
• 30 % of accommodation
amplitude in diopters
179
4 - Accommodative disorder assessment –
MEM
• It is recommended to do it according the horizontal axis
• We usually do it binocularly
• We use normal room light
• With MEM we can also verify the value of estimated addition
• Expected values are from +0.25 to +0.5 D with SD 0.25 D. MEM values
0, minus values and plus values more than +0.75 are suspicious
180
5 - Primary analysis of accommodative and
non-strabismic disorder – an overview
• It is recommended to use
classification according to Duan
improved by Wick (1987)
• We can distinguish 15
accommodative, motor and
binocular disorders
181
6 - General therapeutic guidelines – case
histories
• At first we need to identify near and far phoria and AC/A ratio
• At the base of these results we distinguish accommodative, motor
and binocular disorder
• Possible cases and their solution:
1. Refractive error correction
2. Prism
3. Fixation disparity and vertical prism
4. Passive therapy: occlusion and atropine
5. Visual therapy
6. Accommodative disorders
182
6 - General therapeutic guidelines: 1 –
Refractive error correction
• At first we recommend adequate
correction of refractive error to
stabilize binocular vision
• We recommend to patient to
use adequate correction of
refractive error at least for 4 – 6
weeks
• It is possible that problem
disappear with adequate
correction. If it is not we
recommend further solution
• For revealing of eye symptoms
we distinguish significantly this
refractive errors:
• Hyperopia 1.5 D and more
• Myopia 1 D and more
• Astigmatism 1 D and more
• Anisometropia 1 D and more on
sphere or cylinder
183
6 - General therapeutic guidelines: 1 –
Refractive error correction – Case history 1
184
Prescription of full correction for hyperop
6 - General therapeutic guidelines: 1 – Refractive
error correction – Add minus or plus
• We use it in patients with accommodative and binocular disorders
• The effect of influence of binocular vision is dependent on AC/A
• Mostly addition helps in convergence excess (we use add to decrease
of near esophoria)
• If the AC/A ration is small we have to use prism
• Often we can also use so called E-lines bifocal lenses for correction of
accommodative strabismus
185
6 - General therapeutic guidelines: 1 – Refractive
error correction – Effect of +1.25 near addition
186
6 - General therapeutic guidelines: 1 –
Refractive error correction – Case history 2
187
Prescribing +1 D addition
6 - General therapeutic guidelines: 1 – Refractive
error correction - Depth of vision and lag of
accommodation
• We know the difference between accommodation stimulus and
accommodation response
• Probably due to depth of vision can be accommodation response
lower than accommodation stimulus
• E.g. emetrop usually accommodate 1.25 D on 40 cm which we can
test with the MEM
188
6 - General therapeutic guidelines: 1 – Refractive
error correction – Add of minus lenses
• We can use minus lenses in exophoria
• This influences accommodation with change of convergence
accommodation to convergence ratio (CA/A)
• Patient maintains fusion thanks to fusion vergence
•
189
6 - General therapeutic guidelines: 1 – Refractive
error correction – Ineffectiveness of adding of
minus lenses
• E.g. in convergence insufficiency with distance orthophoria and near
exophoria in patients with low AC/A ratio
• Using of minus lenses is ineffective in this case
190
6 - General therapeutic guidelines: 2 - Prism
• The most effective is using the prism in patients with divergence
insufficiency, basic esophoria, vertical heterophoria
• Further we can use prism to decrease convergence insufficiency and
basic exophoria values
191
6 - General therapeutic guidelines: 2 – Prism
– Table of recommended prism using
192
6 - General therapeutic guidelines: 2 – Prism
– Case history
193
Full distance correction with prism
6 - General therapeutic guidelines: 2 – Prism
– Prism application
• We can prescribe prism monocularly if the prism is 1.25 D and lower
• If we use prism more than 1.25 D we should divide this value in front
of both eyes
• It is recommended to use lenses made from CR-39 or higher
refractive index with Abbe’s value consideration
• We usually recommend antireflex in lenses with high base value
194
6 - General therapeutic guidelines: 3 –
Fixation disparity and vertical prism
• According London and Wick (1987) it was found that vertical values of
fixation disparity reduction has positive effect on horizontal values of
FD
195
6 - General therapeutic guidelines: 3 – Fixation
disparity and vertical prism – Vertical FD
measuring
• Associated phoria can be measured with Mallett test
• Patient watches nonius line and during eye opening and closing we
look for vertical prism correction which set the test in zero position
196
6 - General therapeutic guidelines: 3 – Fixation
disparity and vertical prism – Case history 1st part
197
6 - General therapeutic guidelines: 3 – Fixation
disparity and vertical prism – Case history 2nd part
198
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine
• Occlusion is usually used in amblyopia, eccentric fixation and
suppression with ARC
• Passive therapy with occlusion or atropine is used for heterophoria
with anisometropic amblyopia
199
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine – Recommended
treatment of anisometropic amblyopia
1. Full correction of refractive error
2. Use add or prism for alignment of fixation axis of both eyes
3. Passive therapy – better eye occlusion or atropine for 2-6 hours
twice a week
4. Active visual therapy leading to binocular functions improving
200
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine – Table of
management of anisometropic amblyopia
201
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine – Case history
202
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine - Basics
• With occlusion or atropine penalization we try to activate visual
pathway of the worse eye
• It the refractive error correction is ineffective we use occlusion for 2-6
hours a day
• If there is no improvement after 3 month it is recommended to start
with other therapy
203
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine - Occlusion
• In patients with intermediate amblyopia (better than 0.1) we start
with occlusion 2 hour per day
• In patients with heavy amblyopia (worse than 0.1) we use 6 hours per
day occlusion
• Patient should be checked every 6 weeks
• If the visual acuity increases with one row we can continue in the
same procedure
• If the visual acuity increases less than one row we extend twice
occlusion time
204
6 - General therapeutic guidelines: 4 – Passive
therapy: occlusion and atropine - Atropine
• Atropine is used already for 100 years. It has huge tradition in
optometry and ophthalmology
• Treatment of anisometropic amblyopia is slow
• Studies showed that is better to use 1% atropine twice a week than
daily
205
6 - General therapeutic guidelines: 5 – Visual
therapy
• Visual therapy is useful for patients with binocular, accommodative
and motor disorders who are not sensitive for spectacle lenses and
prism application
• Visual therapy can be managed ambulatory (periodically visiting the
professional) or at home
• Some researches showed that home based visual therapy has the
same effect as placebo
• If the home based visual therapy is ineffective after 4 weeks it
recommended to change it on ambulatory visual therapy
206
6 - General therapeutic guidelines: 6 –
Accommodative disorders
• If we have symptomatic patient with distance and near orthophoria
and normal AC/A ration the problem can be accommodative, motor,
vergence, fixation disparity, latent hyperopia, cyclophoria or
aniseikonia
• It is recommended to examine accommodative amplitude, facility and
lag (MEM)
207
6 - General therapeutic guidelines: 6 –
Accommodative disorders – Guidelines
• At first we have to check latent hyperopia
• Low astigmatism or anisometropia can cause asthenopia
• If we use plus lenses we can help patient with accommodation
insufficiency or ill-sustained accommodation
• If the patient has problems with releasing of accommodation or with
the change of accommodation adding of lenses is ineffective
208
V. Visual therapy techniques
• Scheiman page 147
209
V. Visual therapy techniques - overview
1. Basic concept introduction (instruments, procedures, guidelines)
2. Fusion vergence methods
3. Voluntary convergence methods
4. Anti-suppression methods
5. Accommodative techniques
6. Motor techniques
210
1 - Basic concept introduction – Types of
instrument
• We can distinguish “instrument training” and “free space training”
• Scheiman recommends to resolve:
1. Anaglyph and polarized filters
2. Lenses, prisms and mirrors
3. Septum and apertures
4. Paper, pencil and tasks
5. Stereoscopes
6. Afterimages, entoptic phenomenon and electrophysiological methods
211
1 - Basic concept introduction – Types of
instrument: 1 - Anaglyph and polarized filters
• Anaglyph and polarized filters divide image of both eyes. We use it in
heterophoria
• Advantages: We can use different stimulus – accommodative and
non-accommodative, we can use it in patient with slight suppression,
it simulates normal visual conditions
• Disadvantages: Young patients are hardly concentrated, instruments
are expensive, linear polarization is direction dependend
212
1 - Basic concept introduction – Types of
instrument: 2 - Lenses, prisms and mirrors
• Lenses change accommodative and vergence demands. Can be used
with polarized and anaglyph techniques
• Lenses can be used for training of accommodation, vergence, eye
motor and anti-suppression exercises
• Advantages: Lenses are very effective for accommodation and
vergence training
• Disadvantages: Young patient lose quickly their concentration. We can
use different fixation targets
213
1 - Basic concept introduction – Types of
instrument: 3 - Septum and apertures
• Septum is mechanical barrier which divide both eyes image, e.g.
Remy’s separator
• Aperture is hole which enables to patient see part of the object with
one eye and the other part with the second eye
• Advantages: It is used for treatment of mild and intermediate
suppression
• Disadvantages: Examination depends on head position. Often is not
possible to adapt vergence in zero position
214
1 - Basic concept introduction – Types of
instrument: 4 - Paper, pencil and tasks
• We can use printed test for training of vergence, accommodation and
exact eye movements
• Advantages: This is cheep technique. Patient has different targets for
mild and intermediate suppression. Usually we use these test for
training of suppression or convergence
• Disadvantages: Sometimes is difficult to attract young patients to
these tests
215
1 - Basic concept introduction – Types of
instrument: 5 - Stereoscopes
• Stereoscope divides physical space into two divided areas of each eye
vision
• The space is usually divided with mechanical barrier, tube, mirror or
prisms
• This technique can be used in patients with experiences of image
separation form other instruments
• Advantages: We can train 3 level of simple binocular vision. It can be
used in patients with deep suppression
• Disadvantages: The sense is unreal, instrumental. Instruments are
expensive
216
1 - Basic concept introduction – Types of
instrument: 6 - Afterimages, entoptic
phenomenon and electrophysiological methods
• We use it for treatment of amblyopia, eccentric fixation, ARC,
strabismus or nystagmus
• E.g. Haidinger’s brushes, Hering-Bielschowski’s afterimages
• Afterimages can be used for training of motor function of the eye
217
1 - Basic concept introduction – Basic
procedures
• Before the visual therapy (VT) is recommend to consider these need:
• Define the difficulty level which is adequate for proper patient
• Be careful for frustration
• You should define the goals and give the reward to patient
• Patient should see improvement during exercises
• Make patient sure that improvement will come in his visual system
• Define and tell particular targets in VT to patient
• Use techniques with feed back, e.g. diplopia, stereo vision, blurry vision etc.
218
1 - Basic concept introduction – Basic
procedures – Feed back mechanisms in VT
• Diplopia
• Blurry vision
• Suppression
• Binocular luster (combination of
two color objects in stereo vision
generates binocular luster)
• Sense of moving
• Sense of flowing
• SILO (small in, large out)
• Localization
• Parallax
• Upper terms will be explained in
separate slides
219
1 - Basic concept introduction – Basic procedures
– Feed back mechanisms in VT - SILO
• Small in, large out
• Patient can see this in change of vergence or vertex distance of
spectacle lenses
• In convergence object seems to be near and small = SI effect
• In divergence object seems to be far and large = LO effect
• If we use plus lens eye image is increased in size, if we use minus lens
image is degreased in size
220
1 - Basic concept introduction – Basic procedures
– Feed back mechanisms in VT – SILO - Picture
221
1 - Basic concept introduction – Basic procedures
– Feed back mechanisms in VT – Localization
• Patient shows where are
positioned fused objects
• Feed back is based on
physiologic diplopia principle
222
1 - Basic concept introduction – Basic procedures
– Feed back mechanisms in VT – Parallax
• Thanks to parallax we can define the direction of object movement
• In convergence fused object moves into same direction as the
patient’s head
• In divergence is it opposite
223
1 - Basic concept introduction – Main
procedures
• For increasing the fusion reserves we can use these procedures:
• The accommodation is stopped in certain level and we change vergence
demands
• Vergence is stopped in certain level and we change accommodative demands
224
1 - Basic concept introduction – Main procedures The
accommodation is stopped in certain level
and we change vergence demands
225
Making easier
1 - Basic concept introduction – Main procedures Vergence
is stopped in certain level and we
change accommodative demands
226
Making easier Making harder
1 - Basic concept introduction – Specific
procedures – Binocular and accommodative
• Before VT starting you should start with ametropia correction, prism
correction or occlusion therapy
• Before vergence therapy you should solve suppression and amblyopia
• Before starting VT you should test visual system functions, e.g. in
convergence insufficiency we test convergence
• You should start with therapy which is suitable for patient
• Use test blurring
• During training we should control PFV, NFV, PRA, NRA (usually one is
increasing and the second decreasing)
• We start with amplitude and then accommodation facility
• We try to equal amplitude and accommodation facility of both eyes
227
1 - Basic concept introduction – Specific
procedures – Motor therapy
228
1 - Basic concept introduction – Specific
procedures – Anti-suppression therapy
• Adapt the training method. Patient should suppress as little as
possible. You can do this to minimize suppression:
• Change light
• Change contrast
• Move with object
• Flash with light
229
2 - Fusion vergence methods
1. Anaglyphs and polarizators (Tranaglyph, Vectogram, PC training)
2. Lenses, prisms, mirrors (Loose prism)
3. Septum and apertures (Aperture rule)
4. Paper, pencil, tasks (Free fusion pictures)
5. Stereoscope
230
2 - Fusion vergence methods: 1 - Anaglyphs
and polarizators – Variable tranaglyph
• Goals: Increasing of NFV and PFV, decreasing latency of fusional
vergence answer and increasing of its velocity
• Equipment: Variable tranaglyph, red-green glasses, pointer
• Procedure: Tranaglyph has red and green part. Moving both parts
nasally we stimulate convergence and temporally we stimulate
divergence
231
2 - Fusion vergence methods: 1 - Anaglyphs and
polarizators – Variable tranaglyph - Picture
232
2 - Fusion vergence methods: 1 - Anaglyphs and
polarizators – Variable tranaglyph - Principle
233
2 - Fusion vergence methods: 1 - Anaglyphs and
polarizators – Variable tranaglyph –
Recommended guidelines
234
2 - Fusion vergence methods: 1 - Anaglyphs and
polarizators – Variable tranaglyph – Other possible
training
235
2 - Fusion vergence methods: 1 - Anaglyphs and
polarizators – Variable tranaglyph – Change of
training difficulties
236
2 - Fusion vergence methods: 1 - Anaglyphs and
polarizators – Variable tranaglyph – Target values
• During exercises we try to reach 20-25 prism BO (PFV) and 10-15
prism BI (NFV)
• For vergence facility we try to reach 20-25 prism BO and 10-15 prism
BI in 15 cpm
237
2 - Fusion vergence methods: 1 - Anaglyphs
and polarizators – Non-variable tranaglyph
• The goals are same like in
variable version
• Patient should reach simple
binocular vision
238
2 - Fusion vergence methods: 1 - Anaglyphs
and polarizators – PC training
• With help of PC programs we can train accommodation, fusion
vergence, saccades and pursuits
• Advantages: It is standardized method, interpreted by the software.
Can be mixed with the traditional methods
• For example: Computer Orthoptics VTS3 Liquid Crystal System,
Computer Aided Vision Therapy
239
2 - Fusion vergence methods - Lenses, prisms,
mirrors – Flipper and loose prism
• Goals: Prisms are used for increasing or decreasing exercise difficulty
• Equipment: Loose prism, prismatic flipper, fixation target (tranaglyph,
vectogram, Lifesaver card etc.)
• Procedure: For example during convergence training if we use prism
BI we increase exercise difficulty
240
2 - Fusion vergence methods - Lenses, prisms,
mirrors – Flipper and loose prism - Picture
241
2 - Fusion vergence methods - Septum and
apertures - Introduction
• Goals: Increasing of NFV and PFV, decreasing of latency of FV and
increase of velocity of FV
• Equipment: E.g. Bernell Aperture Rule trainer and card, flip lens, flip
prism, pointer
• Procedure: We use chiastopic fusion (visual axis are crossed in
comparison with fixation level) and orthoptic fusion. Training is more
difficult like with tranaglyphs. We use pictures with disparity 2.5-30
prism
242
2 - Fusion vergence methods - Septum and
apertures - Picture
243
2 - Fusion vergence methods - Septum and
apertures – Types of cards
• We use different card types for fusion and stereopsis
• Examination is usually done from 40 cm, where 1 mm means 0.25
prism
• Disparity 1 cm changes vergence demand with 2.5 prism, 12 cm refers
to 30 prism
244
2 - Fusion vergence methods - Septum and
apertures – General guidelines
• Aperture is moved to patient as close as possible
• Insert picture with small disparity
• Patient should fuse the pictures
• If patient can not fuse the picture we can use additional lenses or prism
• In case of convergence therapy is level of accommodation in place of
picture and level of convergence in place of aperture
• If the fusion is not possible we use pointer which is inserted behind the
aperture
• We continue in training until patient is able to fuse all cards (12 for
convergence and 6 for divergence)
245
2 - Fusion vergence methods - Septum and
apertures – Modified Remy’s separator -
Introduction
• Goals: Increasing NFV and PFV, decreasing latency of FV, increase
velocity of FV
• Equipment: Paper septum, Lifesaver card, Free Space Fusion card,
stereogram
• Procedure: We use it for divergence therapy (mechanical aperture), if
objects are separated 4 cm in 40 cm divergence demand is 10 prism
BI
246
2 - Fusion vergence methods - Septum and
apertures – Modified Remy’s separator - Picture
247
2 - Fusion vergence methods - Septum and
apertures – Modified Remy’s separator –
Recommended procedure
• Main goal is divergence training
• This procedure is more difficult than in tranaglyph or vectogram
• Patient tries to keep fusion for 10 seconds and then looks to infinity
and then back to fusion
• Divergence fusion difficulty we can increase with increase of fixating
objects separation. We can use plus lenses or BO prism
• We can finish procedure if the patient is able to fuse 15 prism BI (we
train exo deviation of eyes)
248
2 - Fusion vergence methods - Paper, pencil, tasks
– Eccentric circles and Free Space Fusion Cards
(FSFC)
• Goals: Increase NFV and PFV, decrease FV latency, increase FV
velocity
• Equipment: E.g. Keystone opaque/transparent Eccentric Circles,
Bernel opaque/transparent FSFC, flip lenses, flip prism, pointer
• Procedure: It is free-space chiastopic and orthoptic technique. Prism,
lenses and glasses are obligatory. Patient tries to fuse pictures in front
of and behind the fixation level
249
2 - Fusion vergence methods - Paper, pencil, tasks
– Eccentric circles and Free Space Fusion Cards
(FSFC) - Picture
250
2 - Fusion vergence methods - Paper, pencil, tasks
– Eccentric circles and Free Space Fusion Cards
(FSFC) – Basic technique with eccentric circles
251
2 - Fusion vergence methods - Paper, pencil, tasks
– Eccentric circles and Free Space Fusion Cards
(FSFC) – Training guidelines
• Training is performing with the non-transparent cards. Patient tries to
maintain fusion for 10 seconds. After that he look in infinity and back to
fuse pictures
• We can train convergence in different fixation direction
• Further we can train velocity and quality of fusion with frequency 20 cpm
• For divergence training we use transparent cards
• If the patient has problems with divergence we can use pencil behind the
test
• Training can be stopped if the patient has separation 12 cm in chiastopic
fusion and 6 cm in orthoptic fusion
252
2 - Fusion vergence methods - Paper, pencil, tasks
– Eccentric circles and Free Space Fusion Cards
(FSFC) – Lifesaver card
• Principal of training is similar like
with FSFC
253
2 - Fusion vergence methods - Stereoscope
• Goals: Increase NFV and PFV, decrease FV latency, increase FV
velocity
• Equipment: Keystone stereoscope, Bernell-O-Scope, stereoscopic
cards, flip lenses, flip prism, pointer
• Procedure: Brewster’s type of stereoscope contains oculars with plus
5 D lenses. This lenses are separated 95 mm so they induce BO prism.
Pictures are in 20 cm distance
254
2 - Fusion vergence methods – Stereoscope –
Test cards/pictures
• In the stereoscope we can use different types of pictures:
• Convergence and divergence pictures
• Pictures for coordination eye-hand
• Accommodative therapy pictures
• Anti-suppression pictures
• Pictures for superposition, fusion and stereopsis
255
2 - Fusion vergence methods – Stereoscope –
Picture examples
256
2 - Fusion vergence methods – Stereoscope –
Bernell-O-Scope
257
2 - Fusion vergence methods – Stereoscope –
Calculation of accommodation
258
2 - Fusion vergence methods – Stereoscope –
Calculation of convergence
259
2 - Fusion vergence methods – Stereoscope –
Exercises
• It depends on type of card/picture
• The most important thing is to fuse pictures and maintain fusion for
10 seconds
• Further we can change cards distance (changing accommodation) or
cards separation (changing vergence)
260
2 - Fusion vergence methods – Stereoscope –
Cheiroscope
• Cheiroscope can be used for analysis of simple binocular vision
• We use special pictures for cheiroscope for exophoria (separation is
77-80 mm) and for esophoria (separation is less than 77 mm)
• We can also measure vertical phoria on cheiroscope
• Patient with suppression will draw with interruptions
261
2 - Fusion vergence methods – Stereoscope –
Cheiroscope - Pictures
262
3 - Voluntary convergence methods
• Brock string
• Barrel cards
263
3 - Voluntary convergence methods – Brock
string
• Goals: We try to built sense of object going far away, voluntary
convergence ability and normalize near point of convergence
• Equipment: Brock string, flip lens, flip prism, pencil
• Procedures: Brock string contains 3 color beads. We use it usually in
convergence insufficiency, in esophoria to train the proper
convergence
264
3 - Voluntary convergence methods – Brock
string – Therapy 1
• Step 1: We need 2 beads, patient change fixation of anterior and
posterior bead. If patient focus first bead the rear one is doubled
• Step 2: Patient tries to converge more close beads
• Step 3: Patient should eliminate sense of the string and concentrate
on convergence
265
3 - Voluntary convergence methods – Brock
string – Therapy 1 - Picture
266
3 - Voluntary convergence methods – Brock
string – Therapy 2
• We can train also saccades with
Brock string
• But we need 3 strings
• We can also train pursuits
267
3 - Voluntary convergence methods – Brock
string – Therapy 3
• We can change level of difficulty – decrease:
• Minus lenses
• BI prism
• Bead far from the nose
• We can change level of difficulty – increase:
• Plus lenses
• BO prism
• Bead closer to the nose
268
3 - Voluntary convergence methods – Brock
string – Therapy ending
• Successful convergence in distance 2.5 cm from the nose
• Sense of normal convergence and divergence
• Ability to voluntary convergence
• Adequate vergence value
269
3 - Voluntary convergence methods – Barrel
card - Introduction
• Goals: Built the sense of approaching and receding object, built the
ability to use voluntary convergence, near point normalization
• Equipment: Barrel card
• Procedure: Red barrel on the left side and green on the right side.
This test is recommended for patients with convergence insufficiency.
We use it after Brock string training
270
3 - Voluntary convergence methods – Barrel
card – Picture 1
271
3 - Voluntary convergence methods – Barrel
card – Picture 2
272
3 - Voluntary convergence methods – Barrel
card – Procedure and its finalizing
• Barrel card is placed on the nose
• Patient tries to converge and fuse the most distant barrel at least for
10 seconds
• After that patient has to fixate middle barrel
• Finally patient tries to fixate and fuse the smallest and closest barrel
• Finishing: Patient is able to converge at distance 2.5 cm from nose
with adequate convergence and divergence
273
4 - Anti-suppression methods
1. Bar reader
2. TV trainer
3. Red-green glasses with the light
4. Vertical dissociating prism
5. Training of superposition with mirror (mirror superimposition)
274
4 - Anti-suppression methods: 1 – Bar reader
• Goals: We use it for suppression control during BAF therapy and
fusion facility training
• Equipment: Red-green or polarized overlay, red-green or polarized
glasses, flip lens, flip prism or loose prism
• Procedures: Patient tries to red over the dissociating overlay. One eye
can see part of the text and the second eye can see other part of the
text
275
4 - Anti-suppression methods: 1 – Bar reader
– Picture 1
276
4 - Anti-suppression methods: 1 – Bar reader
– Procedure
• Text reading can be followed by BAF training, image skipping with
prism (saccades training) and vergence facility training
277
4 - Anti-suppression methods: 2 - TV trainer
• Goal: We try to decrease depth and frequency of suppression
• Equipment: TV trainer overlay, red-green glasses, TV (monitor)
• Procedure: TV trainer overlay is stick on the monitor. Patient wears
glasses. If there is the suppression part of the monitor is black
• Change of difficulty: We can change monitor distance, use lenses or
prism
• Other goals: We develop stabile simple binocular vision
278
4 - Anti-suppression methods: 3 - Red-green
glasses with the light
• Goals: With R-G glasses and point light we try to decrease depth and
frequency of suppression. This therapy is not suitable for patients
with ARC
• Equipment: R-G glasses, point light, 6 prism
• Description: Patient wears R-G glasses with prism BD on dominant
eye, watching point light, we can change light intensity, its position,
we can move with light and flash with it
279
4 - Anti-suppression methods: 3 - Red-green
glasses with the light – Procedure and its finishing
• Patient wears R-G glasses, leading eye has 6 prism BD, patient
watches point light
• If patient do not see doubled the point light we try to change light
intensity of the point light, or surrounding light or we move with the
point light in space
• Finishing: Patient should see two point lights with prism without R-G
glasses in normal light conditions
280
4 - Anti-suppression methods: 4 - Vertical
dissociating prism
• Goal: Vertical prism makes diplopia, it is suitable for patient with
heavy suppression, e.g. in anisometropia, heterophoria or
intermittent strabismus, can interfere with vergence therapy which
can decrease effect of this therapy
• Equipment: Light point, isolated optotype letter, 6-8 prism
• Procedure: We start with low room light and low point light, if the
suppression is worse in near we start from distance
• Finishing: Patient should see two standard light of the point light in
normal room light
281
4 - Anti-suppression methods: 4 - Vertical
dissociating prism – Further procedures and
finishing
• Training can be combined with training of saccades and pursuits,
convergence and divergence training
• In patients with heterophoria we can observe change of horizontal
object position
• Finishing: Therapy can be finished if patient is able to see with
diplopia (with vertical prism) in normal light room condition
282
4 - Anti-suppression methods: 5 - Training of
superposition with mirror
• Goal: Superimpose the images and protection against suppression
• Equipment: Small mirror, different fixation objects
• Procedure: Patient holds small mirror before right eye in angle 45
degrees and try to superimpose left eye image with the right eye
image
283
4 - Anti-suppression methods: 5 - Training of
superposition with mirror - Picture
284
4 - Anti-suppression methods: 5 - Training of
superposition with mirror - Procedure and
finishing
• We train at first with pictures for superposition and next for the
fusion
• During the training we decrease the size of the pictures
• Finishing: Procedure can be finished if patient can see both pictures.
285
5 - Accommodative techniques
1. Anaglyph and polarized techniques (Red-red rock)
2. Lenses, prism and mirror (Lens sorting, Loose lens rock – mono and
bino, binocular accommodative facility - BAF)
3. Paper, pencil and tasks (Hart’s chart)
286
5 - Accommodative techniques: 1 - Anaglyph and
polarized techniques - Red-red rock - Introduction
• Goals: Anaglyph training for improvement of accommodative
amplitude and facility
• Equipment: R-G glasses, cheiroscope with R-G overlay, trial lenses
• Procedure: Patient observe letters on the plane. Left side is covered
with red overlay. With R-G glasses right eye can see right side, left eye
can see black word/letters on the right side. Patient has to look for
same words on both sides
287
5 - Accommodative techniques: 1 - Anaglyph and
polarized techniques - Red-red rock - Picture
288
5 - Accommodative techniques: 1 - Anaglyph and
polarized techniques - Red-red rock – Important
factors
289
5 - Accommodative techniques: 1 - Anaglyph and
polarized techniques - Red-red rock – Procedure
and finish
• During the exercise we use lenses from +2.5 to -6 D
• In the first phase we do it without time limit, further we reduce time
• Finish: Patient 20 years old should be able to see clearly with lenses
+2.5 to -6 D. In older patients we use lenses only up to half of their
accommodation amplitude
290
5 - Accommodative techniques: 1 - Anaglyph and
polarized techniques - Red-red rock –
Accommodative demand modification
291
5 - Accommodative techniques: 2 - Lenses,
prism and mirror – Lens sorting
• Goals: Patient should be aware of accommodation stimulation and
relaxation and can effectively use it
• Equipment: Uncut single lenses, accommodation optotype (0.2-0.6),
occlusion
• Procedure: In older patient we use minus lenses with power equal to
half of patient’s accommodation amplitude. Patient looks through
lenses and tries to clear optotype and sorts the lenses
292
5 - Accommodative techniques: 2 - Lenses,
prism and mirror – Lens sorting - Questions
• Patient tries to sort spectacle lenses
• We can ask questions:
• Which lens makes object larger/smaller
• Which lens is more difficult to accommodate
• Which lens object move closer/farther
• Patient should be aware of effort for accommodation and des-
accommodation
293
5 - Accommodative techniques: 2 - Lenses, prism
and mirror – Lens sorting – Change of difficulty
and finish
• Decreasing patient’s effort: In patients with accommodation excess
we starting with minus lenses. In patients with accommodation
insufficiency with use only plus lenses
• Increasing patient’s effort: Lenses differs only with 0.25 D, patient has
time limit for sorting
• Finish: We can stop procedure if patient is able to distinguish lenses
with 0.5 D
294
5 - Accommodative techniques: 2 - Lenses, prism
and mirror – Loose lens rock (monocular)
• Goals: Renewing of normal accommodative amplitude and facility
• Equipment: Optotype with different letter size (0.2-0.6), uncut
spectacle lenses from -6 to +2.5 D in 0.25 D steps
• Procedure: Firstly patient tries to make clear text with increasing
power of lens. Secondary patient tries to accommodate alternatively
over plus and minus lenses
295
5 - Accommodative techniques: 2 - Lenses, prism
and mirror – Loose lens rock (monocular) - Picture
296
5 - Accommodative techniques: 2 - Lenses, prism
and mirror – Loose lens rock (monocular) –
Exercise finishing
• In patients up to 20 years we try to stabilize accommodation through
+2.5 D to -6 D with frequency 20 cpm
• In older patients we use strongest minus equal half of the patient’s
accommodation amplitude
297
5 - Accommodative techniques: 2 - Lenses,
prism and mirror – Loose lens rock (binocular)
• Goal: Renewing of the accommodation amplitude and facility during
suppression elimination
• Equipment: Reading text (0.2-0.6), uncut lenses from -6 to 2.5 D, 6
prism vertically
• Procedure: Patient wears 6 prism vertically and reads. We use +2.5 to
-6 D. Secondary we use binocularly +/- 0.5 D to +2/-4 D with
frequency 20 cpm
• Finishing: Patient should accommodate from +2.5 to -6 D with
frequency 20 cpm
298
5 - Accommodative techniques: 2 - Lenses,
prism and mirror – BAF
• Goals: Patient tries to decrease latency and increase velocity of
accommodation
• Equipment: Flip lenses from +/-0.5 to +/-2.5 D, reading text, polarized
or R-G overlays, polarized or R-G glasses, vectogram or anaglyph
• Procedure: Patient uses R-G glasses and overlay. Patient use flip
lenses and tries to see clear the text. We start with +/-0.5 D.
Secondary we can use tranaglyph as the fixation target
• Finishing: We try to reach accommodation and des-accommodation
with lens +/-2.5 D and frequency 20 cpm without suppression
299
5 - Accommodative techniques: 2 - Lenses,
prism and mirror – BAF - Picture
300
5 - Accommodative techniques: 3 - Paper,
pencil and tasks – Hart chart (monocularly)
• Goals: Renewing of normal accommodation amplitude and facility –
range and velocity
• Equipment: Large and small Hart chart, occlusion
• Procedure (3 levels):
1. Patient hold HC in 40 cm before eye, reads first row and then looks at large
HC
2. Patient moves small HC closer. When it is blurry then patient look at large
HC in 5 m
3. Patient moves small HC to distance 2.5 cm from nose
301
5 - Accommodative techniques: 3 - Paper, pencil
and tasks – Hart chart (monocularly) - Picture
302
5 - Accommodative techniques: 3 - Paper, pencil
and tasks – Hart chart (monocularly) - Finish
• Patients younger 20 years ends therapy when clear small HC in 8 cm
from nose and large in 3 m
• Older patients have small HC in distance which refers to their
accommodation amplitude
303
6 - Motor techniques
1. Lenses, prism and mirrors (Loose prism jumps)
2. Paper, pencil and tasks (Hart chart, letter or symbol tracking, visual
tracking, rotator, flashlight tag)
3. Afterimages
304
6 - Motor techniques: 1 - Lenses, prism and
mirrors – Loose prism jumps
• Goal: We try to make saccades more exact and rapid, done
monocularly
• Equipment: Loose prism 12, 10, 8, 6, 5-1 and 0.5 prism, different
fixation targets
• Procedure: One eye is covered, we introduce prism in front of
uncovered eye, this eye has to refixate making saccadic motion. We
start with larger saccades (higher prism) and larger objects. We use
prism base in all direction
• Finish: Patient is able quickly and exactly make the saccadic motion
for far and near
305
6 - Motor techniques: 2 - Paper, pencil and
tasks – Hart chart
• Goals: Increasing of velocity and exactness of the saccades with HC
• Equipment: Occlusion, large distance Hart chart
• Procedure: HC is placed in 3 m distance. Patient has covered one eye.
Patient has to read 1st letter from 2nd row etc.
• Finishing: Patient should exactly read letters in HC which are
surrounded by other letter
306
6 - Motor techniques: 2 - Paper, pencil and
tasks – Hart chart - Picture
307
6 - Motor techniques: 2 - Paper, pencil and
tasks – Letter or symbol tracking
• Goals: If patient connect letters or symbols it will increase his
exactness and velocity of saccadic eye movements (monocularly)
• Equipment: Letters and symbols, occlusion, transparent plastic foil
• Procedure: In letters patient connect letters according to alphabet, in
symbols according to task
• Finish: We try to equal test time for both eyes
308
6 - Motor techniques: 2 - Paper, pencil and
tasks – Letter or symbol tracking - Picture
309
6 - Motor techniques: 2 - Paper, pencil and
tasks – Visual tracking
• Goals: Improving of exactness and velocity of the pursuits
• Equipment: Visual tracking workbooks, plastic transparent foil,
occlusion
• Procedure: Cover one eye, with uncover eye we connect letter A with
number. Patient should define the numbers
• Finish: For every exercise we have normative time. We training as
long as we reach normative time
310
6 - Motor techniques: 2 - Paper, pencil and
tasks – Visual tracking - Picture
311
6 - Motor techniques: 2 - Paper, pencil and
tasks – Rotator
• Goal: Improvement of pursuits velocity
• Equipment: Rotating Pegboard, automatic rotating instrument,
occlusion
• Procedure: Patient has to insert objects in holes of rotating
instrument
312
6 - Motor techniques: 2 - Paper, pencil and
tasks – Rotator - Picture
313
6 - Motor techniques: 2 - Paper, pencil and
tasks – Flashing tag
• Goal: Increase of quality and velocity of pursuits
• Equipment: Two light sources, occlusion
• Procedure: We project light on the wall and patient tries to
superimpose this spot light (simultaneously)
314
6 - Motor techniques: 3 - Afterimages
• Goals: We try to improve exactness of saccades and pursuits with the
feed back for patient
• Equipment: Camera with the flash
• Procedure: We form narrow slit on the camera’s flash, one eye is
covered, we produce patient’s afterimage, after that patient has to
blink or we switch the light on and off. Patient should se afterimages
everywhere he looks
• Finish: This method can be combined with Hart chart or automatic
rotary instrument
315
References
• Wikipedia. Behavioral optometry [online]. c2014. Cited 15.7. 2014. Accessible at:
http://en.wikipedia.org/wiki/Behavioral_optometry
• B. J. W. Evans: Pickwell´s: Binocular vision anomalies. Butterworth-Heinemann; 2002.
• A.W. Reichow: Sports Vision (Introduction to Behavioral Optometry). Optometric Extension
Program Foundation, 1993
• C.R.Olson, M.Behrmann, R.Kimchi: Perceptual Organization in Vision : Behavioral and Neural
Perspectives. Psychology Press; 1 ed. 2003
• R.C. Pepper, M.J.Nordgren: Behavioral Vision : A Multi-Sensory Approach to Processing
Information & Learning. Optometric Extension Program 1998
• Wondratschek, Oliver. Funktionaloptometrie und Visualtraining : inform Nr. 17. Heidelberg : DOZVerlag
Optische Fachveröffentlichung GmbH, 2006. 96 s. ISBN 978-3-922269-65-6.
• Scheimann, Mitchell; Wick, Bruce. Clinical Management of Binocular Vision. 2nd Edition .
Philadelphia : Lippincott Williams & Wilkins, 2002. 713 s. ISBN 07-8173275-1.
• Schrot, Volkhard. MKH in Theorie und Praxis. Heidelberg : DOZ-Verlag Optische
Fachveröffentlichung GmbH, 2008. 250 s. ISBN 978-3-922269-89-2.
316