Paralytic strabismus

Introduction to paralytic strabismus The strabismus caused by the nucleus, nerves, and extraocular muscles that control the eye movement itself is called paralytic strabismus. The obstacles associated with eye movements are typical features. It is a kind of non-common strabismus. Non-common strabismus is divided into two types: spastic strabismus and paralytic strabismus. Strabismus caused by primary muscle (nerve) spasm is extremely rare, and is only seen by chance in tetanus, neurosis, and the like. basic knowledge The proportion of illness: 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: dizziness

Cause of paralytic strabismus

(1) Causes of the disease

The etiology of paralytic strabismus is complex and may be part of a systemic disease. In the diagnosis and treatment of patients with paralytic strabismus, it is necessary to pay attention to the general condition so as not to delay the disease.

Congenital factors (25%):

Mothers are exposed to environmental hazards during pregnancy, such as pesticides, organic solvents, heavy metals and other chemicals, or excessive exposure to various rays, or taking certain drugs, or infected with certain bacteria, and even some habits, such as sauna ( Steam baths and eating wells may cause congenital abnormalities in the fetus, but they are not genetic diseases.

Nerve paralysis (45%):

Common in (1) trauma such as the bottom of the skull, trauma to the eyelids and concussion. (2) inflammation such as peripheral neuritis, brain and meningitis. (3) Cerebrovascular diseases such as cerebral hemorrhage, thrombosis, etc. (4) Tumor or intracranial tumors. (5) Endotoxin and exotoxin such as lesion infection, alcohol, tobacco, lead, carbon monoxide, carrion poisoning, etc. (6) Systemic diseases such as exophthalmia goiter, diabetes, etc.

Injury and illness (20%):

Direct injury to the extraocular muscles and myogenic diseases may cause paralytic strabismus, such as myasthenia gravis.

(two) pathogenesis

Lesions associated with extraocular muscles or innervating muscles of the eye cause abnormalities in the movement of the extraocular muscles.

Paralytic strabismus prevention

Prevention of children's strabismus focuses on eliminating the conditions that cause strabismus. Try not to keep children away from objects in the same direction and in the same direction. If you find that your child has strabismus at 4 months, try the following simple method: if it is internal oblique, parents can Talk to your child at a remote location, or hang some colorful toys in a distance that is far away, and let the children see more things that move.

Paralytic strabismus complications Complications

Can be complicated by diseases such as the brain and endocrine system, acquired optic palsy strabismus can cause recurrence, eye vertigo, affecting normal work and life.

Eye-induced vertigo. Non-motor illusion vertigo, mainly manifested as instability, increased when the eye is excessive, and relieved after closed eyes. Dizziness lasts for a short period of time. When you look at the moving objects, you will get worse. After you close your eyes, you will ease or disappear. Often accompanied by blurred vision, decreased vision or double vision. Visual acuity, fundus, and eye muscle function tests are often abnormal, and the nervous system has no abnormalities.

Paralytic strabismus symptoms common symptoms nausea diplopia vertigo gait instability eyeball prominent paralysis

Paralytic strabismus has its own unique symptoms. It is different from common strabismus in terms of symptoms and signs, and its characteristics can be explained from two aspects: self-consciousness and sensation.

Conscious symptoms

(1) Diplopia and visual confusion: In addition to congenital and paralytic strabismus in the early postnatal period, diplopia and visual confusion are the first symptoms of patients with paralytic strabismus, often found on the day after the onset, the patient consciously The object has a ghost image. After the eye is covered, the ghost image disappears. It is for double vision. Because the eye position is skewed, when the target is gazing, the object image falls on the macular area of the eye, and also falls on the retina outside the erythema area. These two imaging points are not a pair of corresponding points of the retina, so when the visual stimuli received by the retinas of the two eyes pass through the visual path to the visual center, it is impossible to merge into one and feel two objects, and the confusion is two eyes. The image received by the macular area (corresponding point) is different. The two images overlap each other in the visual center. Like a photo with 2 exposures, the image is blurred and is regarded as one of the characteristics of paralytic strabismus. Trouble, the patient can have dizziness, and even nausea and vomiting, but those with mild diplopia often have no obvious symptoms. Only when the eyes are blurred, if they are examined separately, there is no abnormality, and the visual acuity is normal, often misdiagnosed as no. Sick or Functionalized disease, should be noted clinically.

In patients with congenital paralytic strabismus, the binocular vision is not developed or matured at the time of onset, so there is very little diplopia and visual confusion. In patients with acquired paralytic strabismus, binocular vision is well developed, and soon after the onset, due to diplopia Or feel uncomfortable due to confusion, some patients can overcome with the compensation of the head position, severe cases will appear dizziness and nausea, vomiting, must close a look to make the symptoms disappear.

(2) Eye vertigo and gait instability: The cause of dizziness is mainly caused by diplopia and visual confusion. When the eye moves, the oblique angle of view changes continuously so that the object viewed is not stable, the symptoms are more obvious, and after covering one eye Symptoms can disappear, horizontal diplopia and gaze at a single target without background, the symptoms caused by rotatory diplopia and gaze at complex backgrounds are more obvious, and nausea and vomiting can occur with severe symptoms. Due to the sudden deviation of the eye position, the visual positioning function is broken, and the gait is unstable when the patient walks, and is often skewed in a certain direction.

(3) Abnormal projection: When a patient with paralytic strabismus looks at an object with an eye and tries to touch the object by hand, the hand can not accurately touch the object and is biased toward the side of the paralysis muscle. The distance of displacement is often more than actual. The strabismus is still large, because when the gaze is used, the function of the paralyzed muscle is lost or obviously insufficient, so that the macular area of the affected eye cannot be directly facing the front, or the direct antagonism of the numb muscle requires a super-constant relaxation to make the macular area. In the forward direction, the proprioceptor sends out a message, and the hub issues an instruction according to the accepted error message, so the target cannot be accurately contacted. This abnormal projection is also called a false projection.

2. He feels symptoms

(1) restricted movement: restricted eye movement is one of the main symptoms of paralytic strabismus. The paralyzed eye is restricted to the direction of the paralysis muscle. The eye movement includes both eye movement and monocular movement. First observe the horizontal movement of both eyes. The extent of eye rotation is not difficult to find the direction and eye of the horizontal movement limitation. It can diagnose the internal rectus muscle or the external rectus muscle paralysis. When checking the vertical movement, the internal or external rotation position should be used to make the patient follow the visual target upward or upward. Turn down, so as to check the vertical eye movement according to the diagnostic eye position. If you find that the movement in a certain direction is restricted when checking the movement of both eyes, you should cover one eye and check whether the movement of the single eye has motion limitation in the same direction, because some diseases are longer. Patients with common strabismus may have partial limitation of binocular movement, but normal eye movement is normal. Patients with paralytic strabismus have movement limitation regardless of both eye movements or monocular movement. When examining eye movements, it is necessary to observe whether the cleft is observed at the same time. With or without opening, the eyeball has no change in the degree of protrusion, whether the pupil changes, and other abnormal movements that occur at the same time.

(2) Deviation of the eye position: In general, extraocular muscle paralysis must cause the opposite direction of the eye to the paralyzed muscles. For example, when the right lateral rectus muscle is paralyzed, the external rectus muscle is the external muscle. The eye is deflected inward, and the eye position is obviously skewed. It is not difficult to find with the naked eye, but when it is not fully paralyzed, especially if it can be compensated by head position or with fusion reflex control, there may be no obvious eye position deflection. If the extraocular muscle is not paralyzed without eye tilt, the subject will first be corrected, the right eye, the left eye, the eye position, the light extraocular muscles, and the paralyzed eye. It can be expressed as an eye position deflection only when the eye is eye-catching, and conditional examination with a collimator or a triangular prism can be used to detect eye tilt and non-common strabismus with small inclination.

(3) The difference between the first and second oblique angles of view: the first oblique angle of view is also called the primary deviation, which refers to the skewness of the paralyzed eyes when looking at with the healthy eyes, and the eyes with the eyes when looking at the paralyzed eyes. The skewness is called the second oblique angle or secondary deviation. According to the Hering rule: the nerves received by the two eyes are equal in intensity and have the same effect. The Sherrington rule: the contraction of each muscle is always accompanied by the same In a certain proportion of the relaxation of antagonistic muscles, if the paralyzed strabismus is gazing with the affected eye, in order to maintain the eye in the original position (first eye position), there must be excessive nerve excitation to reach the paralysis muscle, and its antagonistic muscle. The corresponding excessive relaxation, the muscles of the healthy eyelid muscles also received strong excitement, the performance is too strong, so the second oblique angle of view is larger than the first oblique angle of view, when checking the deviation of the eye position, should pay attention to the right Whether the squint when the eye is gazing and the left eye is equal.

(4) strabismus varies depending on the direction of gaze: due to paralyzed extraocular muscle dysfunction, the rotation of the eyeball to the direction of the paralysis muscle is limited. When the eyeball moves, the strabismus changes due to the direction of the gaze, and when the eyeball rotates toward the direction of the paralysis muscle When there is a movement disorder in this direction, the strabismus is obviously increased. When the rotation is in the opposite direction, the muscle function is normal and there is no movement disorder, so the strabismus is significantly reduced or even disappeared, because the paralyzed muscle rotates in all directions when the eyeball rotates in all directions. The effect is different, so the strabismus when looking at different directions is different, and the strabismus is the largest when looking at the direction of the paralysis muscle. Therefore, when examining the strabismus of patients with paralytic strabismus, it is necessary to pay attention not only to comparing the oblique gaze of the two eyes. Degrees, but also pay attention to whether the inclination when gazing in different directions is equal, such as the angle of view of each gaze direction can be measured by means of a prism or a homophone, even when the muscle is not fully paralyzed, this phenomenon can be found.

(5) Continued common strabismus: an extraocular muscle paralysis can cause dysfunction and secondary changes in the ipsilateral and contralateral eyes. These secondary changes complicate the situation and make it difficult to diagnose. For example, extraocular rectus paralysis, after anterior right rectus muscle paralysis, its antagonistic muscle - right internal rectus muscle hyperfunction; its spouse muscle - left internal rectus muscle function is too strong; its indirect antagonistic muscle - left lateral rectus muscle The function is weakened. At this time, there is insufficient or lost function of the rectus muscles and the double rectus muscles. After a certain period of time, the function of the paralyzed muscles is partially restored. The functions of the four muscles are gradually coordinated, which is expressed as the function of both eyes. The esotropia with insufficient hyperfunction and external rotation function, and the characteristic of common strabismus, called continuous common esotropia, is not easy to distinguish from primary common esotropia. Due to the continuous muscle changes, some patients have longer vertical periods. Muscle paralysis, the lesion can be caused by a single upturned muscle paralysis, or the identification of the lower eye muscle paralysis of the other eye is very difficult, for example, the left oblique sacral paralysis is characterized by left erotic strabismus and restricted rightward rotation. Connect Can cause its antagonistic muscle - the left inferior oblique muscle hyperfunction, its partner muscle - the right lower rectus muscle function is too strong, its indirect antagonism of the muscle - the right upper rectus muscle function is insufficient, this time is manifested as left eye strabismus, left eye down And the right eye upturn function is not enough, to identify the primary paralysis muscle is the left oblique superior or the right upper rectus, if the patient or parents can not detail the condition, it is not easy to determine.

(6) Compensatory head position: The compensatory head position is to use the compensated gaze reflection to compensate for the deficiency of a certain extraocular muscle function, so that it does not produce double vision within a certain gaze range, and maintains the abnormal posture of binocular single vision. In other words, the direction of turning to the maximum distance of the complex image, that is, the direction in which the paralysis muscle acts, the compensatory head position is composed of three parts.

1 face left/right turn: face left/right turn, eyes gaze in the opposite direction to overcome horizontal diplopia, when the horizontal muscle paralysis, turn toward the direction of the paralysis muscles, the eyes look in the opposite direction.

2 When the muscles are paralyzed, the ankles are adducted and the eyes are upwards.

3 head tilt to the left/right shoulder: the head tilts to the left/right shoulder to overcome the rotatory double vision (ie, the object tilt), and most of it is inclined to the neck shoulder of the lower eye side.

Paralytic strabismus examination

There is no special laboratory examination, and cerebrospinal fluid examination can be performed when necessary with craniocerebral diseases.

The purpose of non-common strabismus examination is to find the affected muscles, to make a clear diagnosis, to explore the nature and cause of the lesions, and to analyze and select appropriate treatment plans according to the examination.

More obvious extraocular muscle paralysis, the diagnosis is not difficult, but for some cases with slight paralysis or long-term disease has formed a secondary change, it is often necessary to carry out a variety of examinations or repeated examinations in order to make a diagnosis, Therefore, many inspection methods have been designed over the years. In recent years, with the advancement of science and technology and the application of microcomputers, the inspection methods have been increasing and improved, providing more scientific basis for clinical diagnosis. Complex, should pay attention to the inspection: for different types of extraocular muscle paralysis, should choose the appropriate inspection method; inspection should be careful, serious, and should pay attention to repeated inspections, so that several inspection results are comparable; for each inspection result It should be carefully analyzed whether it is meaningful or reasonable; if the patient is a child, the appropriate examination method should be selected according to the degree of cooperation.

The examination of non-common strabismus is summarized in two categories, namely qualitative examination and quantitative examination of the extraocular muscles. In addition, it should be used for visual acuity, eyelid movement, fundus and neurological auxiliary examination.

1. General inspection

(1) Vision and refractive examination:

Some congenital or early postpartum paralytic strabismus can be combined with different degrees of amblyopia. The necessary amblyopia should be treated after surgery to correct the eye position. In addition, for patients with ametropia, refractive error should be corrected before surgery.

(2) Examination of eyelid movement: oculomotor nerve palsy can be combined with ptosis, mandibular lateral motion of Marcus-Gunn syndrome with drooping eyelids, periodic oculomotor nerve paralysis showing periodic cleft palate small and open, endocrine The splitting of the extraocular muscle paralysis is delayed and the upper jaw is delayed. The eyeball of Duane syndrome is receding, the cleft palate becomes smaller, and so on.

(3) Neurological auxiliary examination: it is a necessary method to identify the cause of non-common strabismus, especially for acquired paralysis. If the patient has the same direction of movement and anorexia dysfunction, the neurologist should be asked to assist in the examination.

2. Eye position examination

Observing the eye position is the most useful preliminary examination for various types of strabismus. For non-common strabismus, theoretically, any dysfunction of the extraocular muscles should show a certain degree of eye position deflection, and the direction is to the affected muscle. The contralateral side of the direction of action is skewed. However, if the degree of paralysis is slight and the eye position is controlled by fusion reflection, it can only appear as oblique and the appearance is not oblique. If an oblique position is found, the following 5 points should be noted:

(1) The skew direction is internal oblique, external oblique or vertical oblique.

(2) Whether the first oblique viewing angle and the second oblique viewing angle are equal.

(3) What eyes are gaze eyes, and what eyes are squinting eyes, sometimes squinting eyes are not necessarily numb eyes, especially those who are not numb, such as paralyzed eyes, which are dominant eyes, often appear as non-paralyzed eyes, because this can not only Still taking the dominant eye as the gaze, and making the distance between the complex images larger, so that it is easy to suppress the surrounding objects and eliminate the trouble of double vision, that is, the purposive strabismus, which should be further examined and analyzed. In order to avoid making a diagnosis error.

(4) Record the inspection results in detail, such as when one eye is deflected in a certain direction in the first eye position.

(5) If the vertical oblique position is horizontal, whether the horizontal slope is greater than the vertical slope or the vertical is greater than the horizontal slope, the most simple method for checking the eye position is the corneal mapping method, also known as the Hirschberg test. Make a rough estimate of squint.

3. Eye movement check

Eye movement limitation is one of the main signs of non-common strabismus, and it is also the main identification point of common strabismus. It is not difficult to recognize the eye movement limitation caused by severe paralysis, but in mild paralysis cases, the first eye The position may not show the deviation of the eye position or only slight deviation. If only the naked eye or only the movement of the single eye is observed, the abnormality may not be found. It is necessary to pay attention to the limitation of the joint movement of the eyes because the eyeball acts on the numb muscle. When the direction is rotated, the partner muscles will show excessive exercise, so the eye movement examination should include monocular motion examination and binocular motion examination.

(1) Monocular motion check: The eye movement is performed along three fixed axes (horizontal axis X axis, vertical axis Z axis and front and rear axis Y axis), horizontally rotating along the X axis, and rotating up and down along the Z axis. The Y-axis is used for internal and external rotational movements. The former two are voluntary movements, and the latter are involuntary movements. The range of normal eye movements is: the outer rotation is the maximum for the outer edge of the cornea to reach the external angle, and the inner rotation is the maximum for the inner edge of the pupil. The upper and lower punctum are connected. The maximum rotation is the lower edge of the cornea and the inner and outer iliac lines are at the same horizontal line. The maximum rotation is the upper edge of the cornea and the inner and outer iliac lines are at the same horizontal line. The upper end of the vertical meridian of the cornea is internally rotated to the nasal side, and the external side is externally rotated. When examining, the patient's eyes can be guided to the left, right, up, down, squat, underarm, and nose from the first eye. Move up and down the nose to check whether the eye movement has reached the above position, and whether there is tremor-like movement.

(2) Two-eye joint exercise check: Normal eyes of both eyes are coordinated at any time, and they are coordinated at the same time. They are also simultaneous and equal, equal-speed common exercises. The two-eye joint exercise check is mainly to observe each diagnosis. The coordination of the two eyes in the eye position, the so-called diagnostic eye position refers to the eye position turned by the same direction of the six pairs of partner muscles of the two eyes, namely:

Right right lateral rectus muscle left internal rectus muscle

Left left lateral rectus muscle right medial rectus

Right upper right upper rectus muscle left lower oblique

Right lower right lower rectus muscle upper left oblique

Left upper left upper rectus muscle right lower oblique

Left lower left lower rectus muscle upper right oblique

When performing the same direction motion examination, observe whether the above six directions are rotated or not, whether the eyes are skewed, the slope is consistent, etc., and sometimes the secondary partner's muscle function is too strong, which can be very prominent. Insufficient function of the original paralyzed muscle is often concealed. For example, the right rectus muscle is not fully paralyzed in the right eye. The patient uses the common paralyzed eye as the gaze eye to increase the complex imaging distance, and the left subocular oblique muscle function is obviously too strong. Rectal paralysis or left oblique sacral paralysis is difficult to distinguish from the diagnosis of the eye position, and must be further identified. Commonly used identification methods include cover test and Bielschowsky test.

Diagnostic eye position examination is very important for the diagnosis of common strabismus and non-common strabismus. When diagnosing the AV sign, you should also pay attention to the oblique angle of view of the first eye position and turn upwards. Oblique viewing angle.

4. Compensation head position inspection

Although the compensatory head position is one of the signs of non-common strabismus, not all non-common strabismus has a compensatory head position. This is because the longer-term extraocular muscle paralysis has the commonality and the original compensation. Head position can change; some congenital or old extraocular muscle paralysis can form monocular inhibition or amblyopia, so that the compensatory head position disappears.

The compensatory head position measuring instrument is designed according to the principle that the head is deflected according to the X, Y and Z axes, and is mainly composed of two dials, two long arms, one secondary arm and two short arms. The disc and the arm are fixed by screws. When the screw is loosened, the arm can rotate and slide. The two long arms are both 60cm and the secondary long arm is 40cm. Both are bent at right angles at the midpoint. The two short arms are each 15cm long. The end is also bent at a right angle so that it is easy to align the front midpoint between the eyebrow and the lower jaw when measuring.

5. Covering the joint test

Also known as the screen commitance test, it is a qualitative test designed according to the Hering rule, that is, the same amount of nerve impulses simultaneously reaching the mate muscle, to distinguish the squint changes between the two eyes and the two eyes. Whether the motor function is coordinated or not, the primary and secondary skew can also be determined by covering the eye of the eye with the cover, so that the patient can look at each of the diagnostic eyes with the other eye. At this time, the patient only looks at the target with one eye, and checks You can observe the relative position of the two eyes at the same time. The cover can be placed on the left or right side of the eye to observe the movement of the right or left eye. It can also be placed in the middle of the patient's eyes or on the cheeks of the patient. Observe the coordination of the left and right eyes to the lower left and the lower right.

6. Complex image inspection and analysis

Diplopia is the earliest complaint of the patient and the main cause of the patient's visit. The cause of the diplopia is mostly caused by extraocular muscle paralysis. It can also be seen in the early stage of pediatric common strabismus. The child is younger, unable to complain, adaptable, and soon inhibited, retinal abnormalities and amblyopia, overcoming this perceptual disorder, eventually disappearing, acute common strabismus in some adults Suddenly start strabismus and double vision, but the eye movement is good, and the distance between the complex images in all directions is equal. Therefore, the patient who has the double vision of the main complaint should be thoroughly examined and analyzed to get the correct conclusion. The complex examination is An examination method that needs to be described by the patient, so it is necessary to cooperate. It is not suitable for children who are too young. The purpose of double vision examination is to judge the numbness muscle and to judge the degree of disease recovery and the therapeutic effect. It is a qualitative test, but it can be verified with the objective examination of the eye position and eye movement. If other inspection tools are not used, its qualitative significance far exceeds the quantitative Significance, especially in mild paralyzed patients, when there is no obvious abnormality in eye position and eye movement, the examination and analysis of the complex image is more useful. It is one of the reliable methods for routine examination of extraocular muscles, but it is not suitable for some congenital or stale Patients with extraocular muscle paralysis have monocular inhibition or abnormal retinal correspondence.

7. Taro test

The head tilting test, also known as the head tilt test, is based on the two internal transversal muscles (upper and lower rectus muscles) and the two external transversal muscles (upper and lower oblique muscles) of each eye. Designed to reverse the principle of vertical motion, it is a simple method to identify the oblique muscles and upper and lower rectus paralysis. It does not require any equipment and complicated skills. It only allows the patient to squat, under normal circumstances. The up-rotation of each eye and the action of a lower-turning muscle are opposite and balanced with each other. When the head is tilted toward the affected side of the shoulder, the affected eye turns positive, indicating upper oblique palsy; if the rectus muscle is paralyzed, the eye is not visible. Turn, or a certain degree of downward rotation, the eye position does not change when the head tilts to the healthy side, because the two vertical rectus muscles of each eye and the two oblique muscles up, down, and the inner and outer rotations cancel each other out. Only the rotation effect occurs. When the oblique muscle paralysis head tilts to the affected side shoulder, the affected eye should be internal rotation, the contralateral eye external rotation, the superior oblique muscle with internal rotation has paralyzed, and can not resist the upper rectus muscle upturning effect. Therefore, it is oblique, such as the inferior oblique paralysis, taking the right lower oblique palsy as an example. When the patient is tilted to the left shoulder, the left eye is rotated internally and the right eye is externally rotated. Due to the paralysis of the main external circumflex muscle of the right eye, the function of the inferior external circumflex muscle of the right eye is enhanced, thus The right eye turns significantly and the eye position is lower. Therefore, when the lower eye is lower toward the high eye, the lower eye is lower, and the lower oblique muscle is paralyzed. For the upper and lower rectus paralysis, because it is not the main rotator, when When performing the steamed bread test, there is no obvious obstacle to the rotation of the eyeball, and there is no significant increase in the separation of the vertical eye position between the two eyes.

8. Monocular and binocular injection visual field examination

The field of binocular fixation test and the field of binocular fixation test are quantitative exercise examinations of the extraocular muscles of one or a group of partners using a curved peripheral perimeter. The method of judging strabismus is judged by the patient's main sense. The range of gaze can be expressed by the circumference. When the examination is performed, the patient's head is fixed and the lower jaw is placed on the jaw frame. When the single eye is inspected, the eye is covered and the eye is inspected. The center of the meter, with the 3mm test mark written with E word, starts from the center of the perimeter, and checks from the inside to the outside along different diameter lines. The patient's head does not move, only follow the target with one eye until the E on the test mark is not visible. Up to the word, in turn, check the up, down, inside, outside and 4 oblique directions of rotation, depicting a picture to identify the motor's motor function, if a muscle is too strong, then the direction of movement The range is more than normal, the normal single eye injection field is turned to 35 ° ~ 40 °, down 50 °, internal and external rotation are 50 °.

The method of checking the binocular vision is basically the same as that of the monocular eye. The difference is that the patient needs to wear red and green glasses, and a small light is often used as a test mark. When checking, both eyes follow the target. When the subject is double vision, the angle is recorded in the field of view. On the table, the readings of the various lines are then connected, that is, the patient's eyes are injected into the field of view, and the visual field defect portion of the binocular eye represents the visual field of the extraocular muscle dyskinesia. The normal range is about 50°, and the method is only applicable to There are still patients with mild paralytic strabismus with binocular single vision in a certain field of view. The purpose of the measurement is to determine the range of the patient's binocular vision. The patient's postoperative or convalescent patients can compare the binocular vision of different periods. There is a correct estimate of the surgical outcome and recovery.

9. Passive exercise test

The forced duction test, also known as the Dunnington-Berke traction test, the eyeball traction test, the forced eye-turn test, the traction test, etc., is a method for identifying adhesion, paralytic or spastic ocular dyskinesia. In the test, 1% tetracaine was used for eye anesthesia before the examination, and then the tendon and conjunctiva to be pulled were clamped with the gums. This method should also be used as a routine before common strabismus and non-common strabismus. Check to determine the surgical method, there are four kinds of traction tests commonly used in clinical practice.

(1) Assisting the eyeball traction test: the method is to use the gingival sac to clamp the tendon and conjunctiva on the restricted side of the eye movement, so that the eye rotates to the affected side, and the examiner holds the fixed sputum and gently pulls it in the direction. If it still cannot rotate, it means that the antagonistic muscle of the affected muscle has mechanical limitation, which may be fixed strabismus caused by anti-muscle spasm, adhesion or muscle fascia abnormality; if there is no resistance to rotation, it means that the affected muscle is paralyzed, no Mechanical restrictions.

(2) Anti-eye rotation test: The method is to use the tendon and conjunctiva that are clamped on one side to fix the eyeball in the direction of the muscle action, so that the eye rotates to the opposite side as much as possible, such as the muscle contraction force. It means that the lack of muscle function is caused by adhesion or contraction of scar tissue against the muscle; if there is no muscle contraction, it means that the muscle is paralyzed or caused by a large amount of retraction.

For example: when exotropia, the external rectus muscle tendon and conjunctiva are clamped with the gums, and the patient is turned and pulled inward. If there is resistance, the external rectus muscle may be tightened; Duane Regression syndrome, external rectus muscle fibrosis; abnormal fascia or muscle attachment or external rectus contracture; fixed exotropia.

If the pull is inward, it may be: the super-constant rectus muscle retreats; Duane retreat syndrome (the central or peripheral contraction of the medial and lateral rectus muscles due to the attempted adduction of the eyeball); Internal rectus paralysis.

In the case of the superior oblique sheath syndrome, the conjunctiva and fascia tissue that is clamped near the nasal corneal edge with the gingival tendon pulls the eyeball to the upper part of the nose and often has a strong resistance. If there is no resistance, the inferior oblique muscle is incomplete. paralysis.

(3) Double-twisted symmetrical traction test: the method is that the examiner holds a toothed scorpion and holds the inner edge and the outer edge of the cornea, or the upper edge and the lower edge, or the upper edge of the nose and the lower edge of the iliac crest, or the upper edge. The conjunctiva and fascia of the relative orientation of the edge and the lower edge of the nose are then pulled to the left and right, up and down or obliquely to determine whether there is mechanical limitation. This method is mostly used for preoperative examination under general anesthesia. , outside rotation check.

(4) Traction test after muscle paralysis: Excessive function of certain muscles can be judged by the above method. It is used when contracture or adhesion is caused by intramuscular injection of 2% lidocaine 0.5ml. Pulling, if the muscles are contracted, it is easy to pull the eyeball after the muscle is paralyzed. If it is caused by adhesion, the eyeball can not be pulled.

10. Several simple diagnostic methods for vertical muscle paralysis

(1) Parks three-step method: Designed by Parks in 1958, it is used to identify the method of rectus paralysis and paralysis. Because the examination is carried out in 3 steps, it is called three steps. Inspection method.

Step 1: Observe the eye in the original eye position, such as the right eye oblique (left eye oblique), indicating the right eye's lower muscle (upper and inferior rectus) or the left eye's upper arm ( One of the four muscles of the superior rectus and the inferior oblique muscle is paralyzed.

Step 2: When checking the right and left eyes, the side is inclined upwards. If both eyes turn to the left at the same time, the right eye (inside the eye) is higher, then the right upper oblique muscle or the left upper rectus muscle paralysis (this Two other suspected paralytic muscles have been excluded.

Step 3: Taro test, positive for oblique muscle paralysis, negative for rectus paralysis.

(2) Schwarting three-point test: The Schwarting three-point test was designed by Schwarting in 1958.

Point 1: Determine which eye is inclined.

Point 2: The squint becomes larger when looking up or down.

Point 3: When the squint is turned to the right or to the left, it becomes larger.

From the table, we can conclude that there are two choices for each point, namely right or left eye, eye up or down, eye right or left, and a total of 6 groups of muscles to choose from, and each group There are 4 muscles in the muscles, but only 1 in 3 points is shared. The muscles shared by these three points are paralyzed muscles. For example, the left eye is oblique, when the eyes are upward and the eyes are left. When the gaze is increased, the muscles shared by the three points have only the right inferior oblique muscle, so the muscle is the paralysis muscle.

(3) Helveston two-step method: a simplified method designed by Helveston in 1967 on the Parks three-step method to identify the superior oblique muscle and the contralateral superior rectus muscle. paralysis.

Step 1: When turning the eye to the left or right, pay attention to the angle of the eye or the oblique, such as the upward rotation of the eye, indicating the paralysis of the superior rectus muscle or the contralateral eye (external eye); Oblique, which means that the inferior oblique muscle or the contralateral eye (external eye) under the rectus muscle paralysis, so that the first step can reduce the four possible affected muscles to two.

Step 2: Tilt the patient's head to the right shoulder or left shoulder. Pay attention to the angle of the eye. If the head tilts toward the high eye, the upper oblique direction increases, indicating that the oblique muscle is paralyzed; if the head tilts toward the lower eye, the upper oblique is increased. Indicates rectus paralysis.

(4) Urist three-step method: Designed by Urist in 1970 to diagnose AV strabismus with vertical muscle paralysis.

Step 1: Determine which eye is oblique.

Step 2: When the head is tilted to the side, the upper slope is the lightest. If the head is tilted to the same side, the rectus is light, which means that the rectus is paralyzed; if the head is tilted to the opposite side, the oblique oblique paralysis.

Step 3: There is no AV phenomenon when looking up and down. The A phenomenon indicates the inferior rectus and the inferior oblique paralysis. The V phenomenon indicates the superior rectus and the superior oblique paralysis.

For example: if the right eye is oblique, the head tilts to the right when it is obliquely light, indicating that the rectus muscle has paralysis, that is, the right lower rectus muscle or the left superior rectus muscle; if the V phenomenon is the superior rectus muscle or the superior oblique muscle paralysis, The common difference between the two is the superior rectus muscle, so the diagnosis is left upper rectus paralysis.

For example, if the right eye is squint and the head is tilted to the left, the oblique oblique is light, which is expressed as oblique muscle paralysis, that is, the right superior oblique muscle or the left lower oblique muscle. If it is A phenomenon, it is the lower rectus muscle or the lower oblique muscle paralysis. The left lower oblique muscle is diagnosed as left lower oblique palsy.

11.Hess screen and Lancaster screen check method

(1) Hess screen examination method: It is used to assist in checking the relative state of nerve excitement during the movement of two eyeballs. It can detect muscles with insufficient function (paralyzed muscles) and muscles with excessive function. It is a quantitative examination method. The Hess screen has a projection type, an electric Hess screen and a screen-mounted Hess screen. Take the screen type as an example: it is a 1 m2 black (or gray) cloth screen, and the surface is made up of red lines to intersect the horizontal and vertical lines. Equivalent to 5° angle, make a red gaze target at the center point, and make a red mark on every 15° and 30° cross line. There are 9 red marks in the center of the screen, which represent 9 diagnostic eye positions. On the lateral, middle, lower and nasal sides, the middle and lower are the six diagnostic eye positions, which represent the direction of action of the six groups of partners, in order to check the function of the extraocular muscles. The original design is to install two pulleys at the upper end of the screen. The green rope is connected by a 2 green rope through the pulley in front of the black cloth screen, and the other end of the two ropes is suspended by a metal hammer, and a green wooden rod is suspended in the center of the connected green rope, and the rod can be touched to contact the red test mark.

In the semi-dark room examination, the subject sits 0.5m away from the Hess screen, the eye is at the same height as the center red dot, wearing red and green complementary glasses, the red mark on the Hess screen is only seen by the fixation eye wearing red glasses. The green indicator light or indicator stick is only visible to the other eye wearing green glasses. The inspector holds a green indicator light or a stick to indicate the red mark position on the Hess screen and check the red mark in the range of 15° and 30°. And record the position it refers to, then exchange the red and green glasses of the left and right eyes and then perform the same inspection, record the graphics, compare the size and shape of the two graphics first, because the second oblique angle of parasitic strabismus is greater than the first The oblique angle of view, so the small eye of the figure is paralyzed, and then analyzed according to the muscles represented by the six diagnostic eye positions. The graphic adduction indicates insufficient muscle strength (paralysis), and the enlarged indicates that the muscle strength is too strong.

(2) Lancaster screen check method: The Lancaster screen has the same principle as the Hess screen, that is, a white cloth screen is used to draw horizontal and vertical black line squares, each grid is 7 cm.

In the dark room inspection, the subject wears red and green complementary glasses to sit at 1m or 2m in front of the screen, so that they hold the green light to overlap the red target, and record the skew of each point in the range of 15° and 30°. Then exchange the red and green glasses, repeat the above inspection, and then measure the displacement degree, which is the actual skewness of the strabismus.

12. Determination of strabismus

Quantitative examination of strabismus is very important for observing changes in the condition, designing the operation and evaluating the effect of the operation. For the determination of the inclination of paralytic strabismus, the following six methods are commonly used.

(1) Corneal mapping method.

(2) Perimeter measurement method: Also known as the peripheral arc-shaped field of view oblique measurement method, that is, the method of measuring the squint degree by using the degree of the field of view meter arc.

(3) Triangular prism cover method: when placing the prism, the direction of the bottom paralysis muscle, the direction of the oblique direction, if there are horizontal and vertical oblique positions, respectively, the prism removal should be performed separately, and the first oblique angle of view and The second oblique angle of view.

(4) Triangular prism plus Maddox rod method.

(5) Triangular elimination complex imaging method: For patients with paralytic strabismus who have double vision of the main vision, the prism can be used to eliminate the complex image by placing the triangular prism in the oblique direction toward the front of the eye and gradually increasing the degree of the triangular prism until the complex image disappears. The prism power is the number of eye position skewness. When the complex image is removed, the prism power can be increased or decreased as appropriate. Try to maintain the range of the prism increase and decrease of the binocular single vision. If the amplitude is wider, the potential fusion force of the patient is greater. Well, the scope of fusion is large; if the range of increase or decrease is extremely small, even the difference of 1 is intolerable, indicating that the patient is weak.

(6) Same vision machine measurement: The same vision machine is the most commonly used instrument for qualitative and quantitative examination of strabismus. The use of the same machine to measure the conscious oblique angle and the slant angle is the diagnosis of paralytic strabismus, the observation effect and the most commonly used before and after surgery. Inspection method.

The same way to check the squint recording method:

1 horizontal squint: generally check 3 eye positions, that is, directly in front, turn left 15°, turn right 15°, record the slope of both eyes.

The format of the clinical record is as follows:

5#

13.

-

14.

Worth

15.

(electromyographyEMG)20300V0.5ms350/s

16.

4(saccade)(pursuit)(vergence)(torsion)(EOG)(ENG)

(1)33mm15°50 /s50cm15°15°10 mm575

150(325°402°)/s50°/s;50°/s;1/31/2 .

(2)20°(20°)1m20°20°20°4510mm/s5mm

10%20%30%15%1994>15%>30%;>30VSEM91.3%EMG80.9%;SEM83.2%EMG88.9%SEM6SEM

17.

Mundt1956196219211973OssoinigA1990A1985B1986ABDA1mm1986B

18.CT

CTHounsfield1969197210CT

diagnosis

Differential diagnosis

1.

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3.

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