Basic introduction nickname: strabi *** us Clinic: Ophthalmology is mostly in children: Common causes of eyes: heredity, hypotonia of intraocular rectus, eye muscle imbalance and other common symptoms: esotropia, exotropia, up and down strabismus, clinical manifestations, examination, diagnosis, complications, treatment, etiology 1. The theory of eye accommodation. Due to the strong accommodation-convergence reflex, the function of medial rectus muscle often exceeds that of lateral rectus muscle, leading to concomitant esotropia. Myopia uses little or no adjustment when looking near the target, and the collective force is weakened at the same time, so the tension of its internal rectus muscle is reduced, sometimes forming concomitant exotropia. 2. Binocular reflex theory Monocular is conditioned reflex, which is completed by fusion function and acquired. If the visual acuity of both eyes is different during the formation of this conditioned reflex, and the function of monocular vision is hindered by the obvious sensory or motor disorder of one eye, there will be a state of eye position separation, that is, strabismus. 3. Anatomical theory: Overdevelopment or hypoplasia of extraocular muscles, abnormal attachment points of extraocular muscles, abnormal orbital development and abnormal intraorbital fascia structure will all lead to muscle imbalance and strabismus. 4. Hereditary theory is very common in clinic. Many people in the same family suffer from concomitant strabismus, which may be related to genetic factors. The clinical manifestation of strabismus patients is that when they pay attention to an object, the image of the object falls on the fovea of the retina of the normal eye, while the strabismus eye falls outside the fovea, so diplopia will occur. The image of one eye is suppressed, losing the single visual function and stereoscopic impression of both eyes, and some will lead to poor vision and amblyopia. 1. The eyes with esotropia deflect inward. Congenital esotropia is called congenital esotropia. The deflection angle is usually large. Acquired esotropia can be divided into accommodation and non-accommodation. Accommodation esotropia is common in children aged 2 ~ 3 years, and children are usually accompanied by moderate to high hyperopia or abnormal accommodation cohesion and accommodation ratio. 2. Exotropia is outward deflection, which can be generally divided into intermittent exotropia and persistent exotropia. Intermittent exotropia can be maintained in a normal position most of the time because of the patient's good image fusion ability, and exotropia will only appear occasionally in the sun or when he is tired and distracted. Some children also show that they often close one eye in the strong sunlight. Intermittent exotropia often develops into persistent exotropia. 3. Up and down strabismus has upward or downward deviation, which is less common than esotropia and exotropia. Up and down strabismus is often accompanied by head skew, that is, compensatory head position. Examination The following is the routine examination method for strabismus: 1. Examination of binocular visual function (1) Syncope is widely used in China to examine the three-level situation of binocular visual function. (2) Quantitative determination of stereopsis function, that is, stereopsis sharpness is determined by stereogram of synoptophore or Yan's random point stereogram. 2. Refraction examination Atropine paralysis ciliary muscle optometry: To understand the relationship between amblyopia and strabismus and refraction. 3. Determine what kind of strabismus is by measuring the eye position and strabismus angle. Surgical design must check the size of oblique angle of view. 4. Eye movement check to judge the function of extraocular muscles and see if eye movement is in place normally. 5. Is there any head position compensation to help diagnose what kind of extraocular muscle paralysis is? 6. Determine the examination of paralyzed muscles. Check the eye movement function, the squint angle of binocular fixation and monocular fixation in all directions. Red lens test or Hess screen method is helpful to determine. 7. Traction test (1) is used to evaluate the tolerance of diplopia before operation and patients after traction to normal position. (2) Passive traction test can know whether there is mechanical restraint or muscle spasm of extraocular muscles. (3) Active contraction test to understand muscle function. 8. Use inclinometer to check the inclination angle and make quantitative determination. Convergence point detection: it is helpful to diagnose muscular asthenopia. 9. Measuring the accommodation set/accommodation ratio (AC/A) is helpful to judge the relationship between strabismus and accommodation and accommodation set. Diagnosis can be made by the following methods: 1. Ask about the medical history. Ask the patient's age, exact onset time, etiology or inducement, strabismus development, what kind of treatment he has received, and whether he has a family history. 2. Eye appearance inspection should pay attention to the direction and degree of patients' eye position deviation, whether the eyelid fissure is equal, whether the face is symmetrical and whether there is a compensatory head position. 3. Vision examination and refractive examination examine the patient's near and far vision and corrected vision in detail. For high myopia, astigmatism and adolescent patients, refractive examination must be carried out after mydriasis. 4. Masking test Masking test can qualitatively check strabismus simply and accurately. 5. Check the eye movement, observe the six main movement directions, and judge whether the function of each eye muscle is abnormal. 6. Oblique viewing angle inspection The oblique viewing angle is divided into a first oblique viewing angle and a second oblique viewing angle. When healthy eyes stare, the angle of strabismus deviation is called the first oblique angle of view; When strabismus occurs, the oblique angle of the healthy eye is called the second oblique angle of view. Measuring the inclination angles of the first and second oblique angles is helpful for the diagnosis of paralytic eyes. The commonly used quantitative measurement methods of oblique angle in clinic include corneal reflection method, synoptophore inspection method, prism matching method and covering method. 7. In addition, there are squint measurement, Mahalanobis bar and prism inspection, visual field measurement and so on. Complications Most strabismus patients' stereoscopic vision is weakened or lost. Those with monocular inhibition may have amblyopia, and some patients may have diplopia and blurred vision. Treatment 1. Non-surgical treatment of strabismus aims at amblyopia first, promotes good vision development of both eyes, and then corrects the deviated eye position. The treatment of strabismus includes: wearing glasses, wearing an eye mask to cover it, and training in orthophoto. Wearing an eye mask is the main method to treat strabismus amblyopia. Eye muscle surgery involves relaxing (weakening) or shortening (strengthening) one or more muscles in the extraocular muscles of one or both eyes. Mild strabismus can be corrected by wearing a prism. In-situ training can be used as a supplement before and after operation. 2. The younger the strabismus surgical treatment, the better the treatment effect. Strabismus surgery is not only to correct eye position and improve appearance, but also to establish binocular vision function. The best time for surgery is before the age of 6 ~ 7. Binocular vision training was performed after operation to enhance and maintain stable stereoscopic vision function.