Translated from Russian to English - www.onlinedoctranslator.
com
Binocular vision
Strabismus
Lecture for students of the
Faculty of Medicine
Binocular vision - this is a unification
activity of the sensory and motor
systems of both eyes, ensuring the
simultaneous direction of the visual
axes to the object of fixation, the
merging of monocular images of this
object into a single visual image and its
localization to the corresponding place
in space.
Single perception
observed object
is possible only under the
condition of simultaneous
central irritation
y fossae of the retinas (a1,
a2) or points of the retinas
remote from the central
pits at the same distance
in the same direction (b1,
b2)
If the image of an object falls on disparate
(non-identical) points of the retina, then
double vision occurs.
A set of points,
giving singles in
binocular perception
normal vision, arr.
learns geometric
place - imagine
1st circle –horopter(In
Ice-Muller).
- In a newborn baby, eye
movements are erratic
- V2-4 weeks strong lightingmakes
you look at him closely
-aged1 month central fixationfleeting and
one-sided
- to the beginning3rd monthare developing
joint movements of both eyes, conditioned
reflex connections between retinal irritation
and eye movements are strengthened. The
act of vision includesconvergence
- To4-5 monthsthe ability appearsfix
objects steadily with both eyes
- To6 monthsis being formedfusion reflex
- formation and formationbinocular vision
derived from6 months up to 6-10 years
and strengthens to15 years old
With binocular
fixing point m
single parts
monocular in
lei view overhead
stack on top of each
other, forming a bino
visual field of vision
nia
Formation of binocular vision.
The necessary conditions:
1.Visual acuity of at least 0.4
2. Well-coordinated function of all
exocular muscles
3. Correct relationship between
accommodation and convergence
4. Symmetrical eye position
5.Good fusion ability
6. Normal functional capacity of the
retina, pathways and higher visual centers
7.Normal connection between
retinocortical elements
8. It is necessary to have a clear image of
the objects being examined and the equal
size of these images on the retina of both
eyes - iseikonia
Binocular vision testing
1. Research using a four-point
apparatus.
2.Reading with a pencil.
3. Sokolov’s test (hole in the palm).
4. Test with knitting needles.
5. Sample with a prism.
Belostotsky-Friedman technique using a
four-point device
"Color test CT-G"
Research using a four-point apparatus.
Binocular vision,
leading eye right
Research on a four-point apparatus.
Binocular vision, dominant eye
z left
Research on a four-point apparatus.
Monocular vision, leading eye
az left
Research on a four-point apparatus.
Monocular vision, leading eye
az right
Simultaneous vision
No fusion
Anisometropia is the cause of different size images on the
retinas. The development of fusion is disrupted and the eye
deviates from the point of fixation
Strabismus (strabismus,
heterotropia)- deviation of one eye
from the general point of fixation,
accompanied by a violation of
binocular vision.
This disease does not manifest itself
only by the formation of a cosmetic
defect, but also by a violation of
both monocular and binocular visual
functions
Classification of strabismus.
I. Imaginary (apparent) strabismus
II. Hidden strabismus (heterophory)
III. Obvious strabismus:
1. paralytic
2. friendly:
- periodic
- permanent
Imaginary strabismus– visual and
optical axes do not match.
If the value of the gamma angle is more
than 3-5 degrees, then a false impression of
convergent or divergent strabismus is
created.
Does not require treatment. Binocular vision
is not impaired.
Heterophoria(hidden cross-eyed
Asian)
Caused by unequal tone of the oculomotor
muscles. Binocular vision is not impaired.
With heterophoria of more than 7-8 prism
diopters, asthenopic phenomena and even
diplopia (double vision) may occur.
Etiopathogenetic factors of
concomitant strabismus
1. Heredity
2. Lability of the nervous system
3. Any disease of the visual analyzer
leading to blindness or decreased visual
acuity
4. Significant difference in the size and
clarity of images on the retina of both eyes
5. Enhanced accommodation and
convergence with myopia
7. Damage to the motor system of the eyes
(nuclear, fascicular, brainstem, orbital
paralysis and paresis of nerves that
control eye movements).
8. Congenital sensory binocular
dissociation
Signs of a friendly
strabismus
1. There are no paralysis or paresis.
2. Full eye mobility.
3. The primary deflection angle is equal to the
secondary one.
4. Occurs in childhood.
5. A squinting eye, as a rule, sees worse,
there is a refractive error
Concomitant strabismus:
* monolateral (monocular)
alternating
* accommodative
non-accommodative
* convergent (esotropia) divergent
(exotropia) superverging
(hypertropia) infraverging
(hypotropia)
* strabismus with amblyopia
strabismus without amblyopia
Monolateral strabismus
Asia
Alternating slant
Asia
Accommodative strabismus
Asia
Changes in the squinting eye
I. Doubling.
II. Confusion or confusion.
III. Inhibition of visual activity of the
squinting eye
Functional scotoma
Amblyopia– reduction of acuity without org.
anic changes in the retina.
Degrees:
- low (vis 0.8-0.4)
- average (vis 0.3-0.2)
- high (vis 0.1-0.05)
By fixation status:
1. Amblyopia with correct (central)
fixation
2. With incorrect fixation a.
with intermittent fixation
b. with stable non-central fixation
V. with unstable non-central fixation
d. with lack of fixation
IV. New functional connections aimed at
restoring binocular vision (false macula)
Foveal fixation Parafoveal fixation Macular fixation
Paramacular fixation Intermittent fixation Peripheral fixation
Examinations:
1. History
2. Eye examination
3. Study of motion ch. apples
4. Study of refraction by an objective
specialist after cycloplegia
5. Study of installation movements
6. Determination of the type of strabismus and the angle of
strabismus
Hirshberg method
7. Determination of visual acuity
8. Determination of the nature of amblyopic
fixation
9. Study of the nature of vision by head
position
The forced position is due to the
patient’s desire to get rid of diplopia and
maintain binocular vision.
Alignment example
I have two images
on the synoptophore
Fuzi research
And
Pleoptics–system of events, for example
aimed at increasing visual acuity in a
mblyopic eye.
Includes occlusion, fixation normalization
and improving visual acuity.
1. Assignment of glasses.
2. Treatment of amblyopia
A. direct occlusion - occlusion better than the
seeing eye.
b. reverse occlusion - occlusion worse than
the seeing eye.
Direct occlusion
A non-reflex ophthalmoscope is used in
combination with the negative sequential image
method. The shadow from the ball is projected
onto the central fovea of the retina, the rest of
the retina is illuminated.
The “blinding stimulation” method is a
helium-neon laser beam. Local irritation by
light or laser of the central fovea of the
retina. The methods disinhibit the function of
the foveal retinocortical elements and make
the central fovea of the retina the place of
best vision.
Pleoptics
Orthoptics–exercise system for times
development of bifoveal fusion, fusion
reserves, eye mobility.
With amblyopic visual acuity of at least 0.4.
Lessons with synoptophore
Surgery
To eliminate symmetrical position
In the eyes, two types of operations are used -
strengthening and weakening the actions of
muscles.
I. Strengthen muscle action:
1.Resection– shortening of the muscle by
excision of its sections at the place of
attachment to the sclera and suturing to
this same place.
2.Tenorrhaphy– shortening of muscles by
forming a fold from the tendon.
II. Weaken muscle action.
1.Tenotomy– notches on the tendons
shts.
2.Recession– muscle movement, relocation
marked at the point of attachment, posteriorly,
suturing it to the sclera.
Muscle resection
Muscle recession
A set of events
carried out at
treatment of concomitant oblique
lasia, called
Pleopto-orthopto-
surgical-diploptic
treatment
Paralytic strabismus Occurs when the nuclei
or trunks of the oculomotor, trochlear and
abducens nerves are damaged, as well as as a
result of damage to these nerves in the muscles
or the muscles themselves.
Signs:
- Paralysis or paresis of any muscle, suturing of
a nerve or damage to the nucleus of this nerve
- Diplopia
- The secondary angle of deviation (healthy eye) is
greater than the primary angle of deviation
(squinting eye)
- Limitation of eye mobility towards the
affected muscle.
- Any age is affected.
- Visual acuity is usually not reduced, and
refraction is age-appropriate.
- History: trauma, intoxication, infection.
Forced position
heads
Treatment of paralytic
strabismus
* treatment of the underlying disease by a
neurologist, neurosurgeon, pediatrician and other
specialists.
* symptomatic treatment by an ophthalmologist
(electrical stimulation, correction of ammetropia
and prevention of amblyopia.
* surgical treatment consists of strengthening
the affected muscle and weakening the
antagonist, plastic surgery for several
big muscles.
Differential diagnostics
Sign Strabismus
Friendly Paralytic
Etiological f Infection, mental Diseases of the central nervous system,
actor real injury, without birth injury
causes
Terms arise Up to 5 years Any age
nia
Eye movements In full Limited
y apples
Symmetry I alternate more often Mono or bilate
defeats more ral
Ne ratio Primary angle ra Secondary angle
primary and secondary veins secondary more primary
oblique angles th
eyes
Diplopia Usually absent Expressed
T
Convergence Saved Violated
Head position Not changed Changed
s
Dizziness Absent Expressed
Restoring f Usually full More often incomplete
functions e
Nystagmus–spontaneous count syndrome
fucking eye movements.
Forms of nystagmus:
1. pendulum-shaped
2. jerky
3. mixed form
Towards:
* horizontal
* vertical
* rotatory
* along oblique meridians
By deviation size:
1. Large-caliber
(oscillation amplitude >15 degrees)
2. Medium caliber (5-15 degrees)
3. Small caliber (<5 degrees)
