Warung Bebas

Sunday, 2 October 2011

STRABISMUS

 Everybody knows what the name of eye abnormalitiy is. yes it's called Strabismus or "Juling" in Indonesian name. Today Mbah Dukun Bagong, modern shaman from Medical and Health Information will share knowledge about ophtalmology. anything about strabismus, from causes, how it can happen until how to treat and prevent, will be explored here.




DEFINITION
Strabismus (crossed eyes) is a condition where the eye is fixed on one object at the center of attention simultaneously. This situation could persist (always visible) or can be intermittent which arise in certain circumstances such as illness or stress. Crossed eyes can see straight and looking straight can look like a cross-eyed.



ETIOLOGY
a. Heredity factors
"Genetic Pattern" is not known with certainty, but the result is obvious. If the parents suffer from strabismus, a successful operation, so when her son was suffering from strabismus and surgery would work well too.
b. Anatomical abnormalities
1. Extraocular Muscle abnormalities
    - Over development
    - Under development
    - the location insertio muscle disorders
2. Abnormalities in the "structure vascial"
Abnormalities vascial relationship extraocular muscles can cause the position deviation of the eyeball.
3. Abnormalities of the orbital bones
Abnormalities of orbital bone formation causing abnormal shape and orbital, giving rise to spherical aberration of the eye.
c. Abnormalities in the nerve center, which can not synthesize stimuli.
d. Fovea can not catch a shadow.
e. Quantity of the stimulus on the muscle abnormality of the eyeball.
f. Sensory abnormalities
Defect that prevents the formation of shadows on the retina properly, among others:
- Turbidity media
- Lesions in the retina
- severe Ptosis
- refraction anomalies (especially those not corrected)
g. abnormalities of innervation
1. Disorder transition process and the perception
This disorder causes the fusion process is not successful.
2. Impaired motor innervation
-  Insufficiency or tonic escessive inervation of the supra-nuclear
-  Insufficiency or exessive inneration of one or several muscles.



CLASSIFICATION
Exotropia

A. According to the Direction of Deviation
1. Exotropia (Divergent Strabismus)
- Frequency less than Esotropia
- Often, an exotropia is starting from exoforia which then progreses into exotopia intermittent exotropia that eventually becomes a constant, if not given treatment
- Most often monocular, but may also alternating.
- Treatment: depends on the cause, these cases often require surgery.


Esotropia

2. Esotropia
a. Non-Paralytic (Comitant)
Non-Accommodative Esotropia, Divided into:
a. Esotropia Infantil
The most frequently encountered. According to the agreement in order to qualify limitation, the occurrence of Esotropia should be before the age of 6 months. The cause is not known with certainty.
b. Acquired Esotropia
i. Basic Esotropia
The emergence in childhood, but no accommodation factor. Angle strabismusnya initially smaller than Congenital Esotropia but it will grow.
ii. Esotropia Myopia
The emergence of the young adults and there is diplopia to look away, which gradually will to look closer.
* Signs clinic:
• In the monocular: anomalous refraction is often more conspicuous in one eye (anisometropia).
• In the alternating: anomalous refraction nearly equal in both eyes.
* Treatment:
• Occlusion: the aim is to equate visual acuity of both eyes closed is a good eye. This occlusion can be combined with Orthoptica, to develop binocular function
• Operations
iii. Accommodative Esotropia
Occurs when there is a normal physiological mechanism of accommodation, but there is relatively less divergence fusion to maintain the eye in order to keep it straight.
There are two pathophysiological mechanisms that occur:
1. High Hiperophia that require strong accommodation to shadow becomes clear, which raised Esotropia.
2. The ratio of KA / A is high, which may be accompanied by abnormalities refraction.
Both of these mechanisms can occur in one patient
1. accommodative Esotropia because hiperophia
Hiperophia is typical, the onset at age 2-3 years, but can also occur in infants / older age
2. accommodative Esotropia because the ratio of KA / A high
Abnormal Convergention reaction occurs when sinkynetic close. Refraction abnormalities may not hyperophia, although frequently found moderate hyperophia.
Because the cause hypermetropia, then the treatment is glasses. If treatment is delayed until 6 months from the onset, will often occur amblypobia. To amblypobia, prior treatment with occlusion.
3. Combination of Both
b. Paralytic (Non-Comitant)
- In strabismus there is always one / more extra ocular muscles are paralytic and paralytic muscles are always one of the lateral rectus muscle, usually as a result of nerve paralysis abdusen.
- Causes:
* Adults: CVA, tumors (CNS, Nasopharyng), inflammation of CNS (Central Nervous System), Trauma.
* baby or young child: birth trauma, congenital anomalies.
- Treatment:
* Operation on a permanent parese
* In adults who experience sudden strabismus, because trauma can wait up to ± 6 months, because of the possibility of there own repairs. During this period of occlusion can be performed on the paralytic eye to avoid diplopia.
3. Hypotropia
Deviation of one eye down the real, by giving names based on the deviation of vertical eye position, whichever is higher, regardless of the specific disease that causes one eye gaze downward (downward squint).
4. Hypertropia: squint to top
Deviation of one eye and above the real
Cause:
- congenital anatomical abnormalities
- Sticking abnormal fibrous bands
- closed head injury
- orbita tumors, brain stem damage and systemic diseases such as myastenia gravis, multiple sclerosis and Graves' disease.
B. According to Manifestations
1. Heterotropia: manifest strabismus (already seen)
A state of the eyeball axis aberrations are apparent where the two visions do not intersect at the point of fixation.
Cause:
- Hereditary
- Anatomic
- Abnormal refraction
- Abnormalities persyarafan, sensorimotorik
- Combination of above factors
2. Heterophoria: latent strabismus (not visible)
Deviations sight hidden axis can still be overcome by fusion reflex.
C. According to Angle Deviation
1. Comitant Strabismus: deviation angle remains constant at various positions
2. Non Comitant Strabismus: the angle of deviation is not the same, in most cases due to muscle paralysis extraocular, therefore often called 'Paralytic strabismus'.
D. According to the Eye Fixation Ability
1. Unilateral strabismus: when a misaligned eye is constantly
2. Alternating strabismus: if both eyes are alternately misaligned
E. According to the duration time is Strabismus
1. Permanent: the eyes seem constantly deviates
2. In certain circumstances such as fatigue, fever, etc.. Eyes sometimes appear misaligned, sometimes normal.
F. Syndrome "A" and "V"
In the pattern "A" looks more esodeviasi / exodeviasi less on
view upward compared with downward view.
The pattern of "V" indicates fewer esodeviasi / more exodeviation the view upward compared with downward view.


CLINICAL MANIFESTATIONS
a. tired eyes
b. headache
c. blurred vision
d. amblyopia
e. fixation cross
f. Hypermetropia
g. diplopia
h. hyperopia
i. Deviation of the eye


DIAGNOSTIC EXAMINATION
a. E-chart / Snellen Chart
Examination of the e-chart used in children from age 3 to 3.5 years, while over the age of 5-6 years can be used Snellen chart.
b. For children under 3 years can be used to
1. Objective with optal moschope
2. With the observation of children's attention with their surroundings
3. With occlusion / close eye paint
c. Determine the refraction anomalies
Do Retroscope after antropinisation with atropine 0.5% - 1%
d. Retinoscope
Until the age of 5 years of anomalous refraction can be determined by the objectives of retinoskopi after atropinisasi with atropine 0.5% - 1%, over the age of 5 years subbjektif determined as in adults.
e. Cover Test: determines the heterotropia
f. Cover Uncovertest: determine the presence of heterophoria
g. Hirsberg Test
Light reflex examination of the flashlight on the surface of the cornea.
Method:
1. The patient looked straight ahead
2. Place a flashlight at a distance of 1 / 3 m = 33 cm in front of both eyes of patients as high as
3. Notice the light reflex from the corneal surface of patients.
h. Combination prism cover test


MANAGEMENT
a. Orthoptic
1. occlusion
Healthy eyes closed and are required to see with the eyes of the amblyopia. partial occlusion should also be able to use a plastic membrane, bands, lenses, or eye covered with a variety of ways.
2. Pleotic
3. Drugs
4. Exercise with synoptophone
b. manipulating accommodation
1. Lens plus / with miotik
Lowering the burden of accommodation and convergence that accompanies
2. Minus lens and drops siklopegik
Stimulate accommodation in children
c. blinkers
If a child suffering from strabismus and amblyopia, the doctor will recommend to train the weak eye by covering the normal eye with special eye patch (eye patch). The use of plaster eye should be done as early as possible and follow your doctor's instructions.
After the age of 8 years are usually considered to be late because the best vision develops before the age of 8 years
d. Botulin toxin injections
e. operative
1. Recession: move a muscle insersio
2. Resertion: cut muscle extraocular


COMPLICATIONS
a. suppression
Enterprises are not aware of the patient to avoid diplopia arising as a result of deviation.
b. amblyopia
Decreased vision in one or both eyes with or without corrective glasses and without any organic abnormalities.
c. Retinal Anomalus Correspondens
A state, where fovea of the eye (which is not misaligned) be physiologically similar, with the fovea of the misaligned eye.
d. defect muscle
Changes secondary to stricture conjunctiva and fascia tissue that surrounds muscle withstand normal movement of the eye.
e. Adaptation of head position
This situation can arise to avoid the use of muscle paralysis suffered efecyt or to achieve the vision binoculars. Adaptation of the position of the head is usually towards the action of the paralyzed muscles.

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