acute concomitant strabismus
Introduction
Introduction to acute common strabismus Acute common strabismus (acuteconcomitantstrabismus, ACS) is a sudden onset of binocular vision, the eyesight is not parallel, the eye position is skewed, accompanied by diplopia, the oblique angle of view is equal in all directions, no extraocular muscle paralysis and no abnormalities in the nervous system examination. A special type of constant strabismus for qualitative lesions. basic knowledge The proportion of illness: 1.3% Susceptible people: no special people Mode of infection: non-infectious Complications: Amblyopia
Cause
Acute common strabismus cause
(1) Causes of the disease
May be associated with fusion dysfunction and central nervous system disorders.
(two) pathogenesis
1. Fusion dysfunction: Humans rely on the brain's corrective fusion and reflex function to maintain the parallelism of the binocular axis, overcome the implicit oblique through the external fusion force, and overcome the external oblique force through the internal fusion force. According to the measurement of most scholars, people have different degrees. The inclination of the eye, the eye position often has a slight tendency to deviate from the parallel position. At this time, the external object image will be projected onto the non-corresponding point of the retina of the two eyes. The inner oblique image is projected on the nasal retina and causes the ipsilateral side. Double vision, external oblique, external object image projected on the temporal retina to cause cross-viewing. In order to avoid such visual disorder, the body uses the corrective fusion reflection mechanism to adjust the eye position to maintain the binocular alignment. Under normal circumstances, the internal fusion force is greater than the external fusion force. For some reasons, such as mental or psychological factors, the external environment and the internal environment, the balance of the extraocular muscles is destroyed, which causes the weakening of the external fusion force. Overcoming the implicit slant, causing the implicit slant to become intermittent or constant implicit slanting, this lack of abduction, the performance in the double vision is much larger than the near view, the strabismus is far greater Close to see, Burian is applying this fusion mechanism to explain acute esotropia and Franceschetti type acute caused by human damage (such as in the treatment of anisometropic amblyopia, cover one eye or lose sight after a disease or injury) The incidence of esotropia, and Bielschowsky type acute esotropia is considered to be related to myopia. Because myopia is uncorrected, the book is close to the book, causing the tension of the medial rectus muscle to increase, while the external fusion force cannot control the tension of the medial rectus. Another kind of compensatory, on weekdays to overcome the implicit oblique, so that the innervation force of the relaxation of the convergence is reduced, it causes esotropia.
In the same way, due to the imbalance of internal fusion force, the external oblique can not be overcome, causing the tension of the lateral rectus muscle to increase to appear as intermittent exotropia or constant exotropia.
2. Central nervous system diseases: It is generally believed that acute common esotropia is benign, without central nervous system diseases, but ACS caused by central causes has been confirmed. Williams has reported that 6 children aged 3 to 10 have brain Tumor-induced ACS, Cui Guoyi received 12 cases of acute common internal oblique in 1988-2001, including 1 case of 4 years old children with cerebellar tumor, esotropia occurred in the age range of 3.1 to 10.4 years, ACS is the first sign, internal slope It is 15°35°, there is no obvious change in the oblique angle between the far and the right, the left eye, the right eye and the left eye are covered with the right eye or the right eye is not changed with the left eye. 3 cases of far vision After correction, there was no change in internal obliqueity; 3 cases had nystagmus; 2 cases had bilateral facial paralysis, 4 cases of cerebellar astrocytoma were found by magnetic resonance or CT examination, 1 case of cerebellar medulloblastoma, and 1 case was confirmed by biopsy. For the cerebral glioma, 2 cases had mild hydrocephalus, ACS did not disappear after returning to normal intracranial pressure, 4 cases underwent strabismus correction, and none of them obtained fusion function. The author believes that acute commonality Internal strabismus may be associated with central nervous system tumors, brain accumulation In some cases, it also works, but only temporarily. Because ACS is often benign, it is often misdiagnosed. Therefore, patients with ACS who have nystagmus and can not be corrected after appropriate surgery or wearing squint should perform nerves in time. A detailed examination of the system to avoid missed diagnosis or misdiagnosis is still unclear about the mechanism of ACS caused by brain tumors.
The incidence of acute common exotropia, in addition to occlusion, is more related to brain diseases, such as removal of brain tumors, post-traumatic craniotomy, python bites, encephalopathy caused by diabetes, and cerebrovascular disorders. Because of the above factors, the fusion function is destroyed, and the original external oblique is changed into a constant exotropia, and there are insufficient convergence and horizontal cross-over diplopia, accompanied by neurological symptoms such as nystagmus and pupillary abnormalities.
Prevention
Acute common strabismus prevention
1. Prevention of strabismus should be taken from infants and young children, parents should pay attention to carefully observe the child's eye development and changes.
2. Infants and young children should strengthen nursing during fever, rash, and weaning, and often pay attention to the coordination function of both eyes to observe whether there is abnormality in the eye position.
3. Always pay attention to your child's eye hygiene or eye hygiene. If the lighting is appropriate, it should not be too strong or too weak. The printed picture should be clear. Don't lie down and read the book. Don't watch TV and play games and computers for a long time, don't look at 3D pictures.
4. For children with a family history of strabismus, although there is no strabismus in appearance, please check with an ophthalmologist at 2 years of age to see if there is hyperopia or astigmatism.
5. When children watch TV, besides paying attention to a certain distance, children should not be allowed to sit in the same position every time, especially the position of the TV.
Complication
Acute common strabismus complications Complications amblyopia
The internal oblique may be caused by the development of common strabismus due to excessive development of the rectus muscle or development of the lateral rectus muscle, or both. The most common complication is strabismic amblyopia. Strabismus amblyopia refers to the absence of organic lesions in the eyeball. The uncorrectable visual function due to the deviation of the eye position, the eye position is skewed, the posterior visual center actively suppresses the squint, and the visual function is suppressed, resulting in macular visual function. Developmental stagnation forms amblyopia.
Symptom
Acute common strabismus symptoms common symptoms pupil abnormal double vision nystagmus
1. Acute common esotropia: 1 sudden onset, first diplopia, then internal oblique, or both; 2 complex as ipsilateral horizontal, equal distance in all directions, complex distance to see far, see near small Some to a certain distance before the complex image disappears, double vision can be more tolerated in the main sense; 3 strabismus can be expressed as implicit oblique, intermittent esotropia or constant esotropia, internal strabismus 10 ° ~ 45 °; 4 eye movement All directions are good, no signs of extraocular muscle paralysis; 5 have a certain binocular vision function, most of them have simultaneous vision and a certain range of fusion force, about half of patients have stereoscopic vision, the best can reach 30; 6 nerves Systematic examination showed no obvious organic lesions.
2. Acute common exotropia: acute common exotropia (acute comitant exotropia) is rare, mostly occurs in young children, rare in adults, often secondary to brain disorders, characterized by the following 6 points:
(1) Sudden feeling of diplopia and exotropia: strabismus is constant at 15° to 40°.
(2) Insufficient convergence function: but the horizontal movement of both eyes is normal.
(3) The binocular vision function is normal: there is obvious cross-viewing.
(4) Electrooculogram (EOG) check: Shows balance tracking impulse.
(5) Sometimes there may be both eyes up and down the same movement disorder: pupil abnormalities and nystagmus may occur.
(6) may have a history of brain tumor resection: history of craniotomy performed by trauma, python bites, encephalopathy caused by diabetes and cerebrovascular disorders.
Examine
Acute common strabismus examination
Without special laboratory examination, imaging examinations such as CT or MRI should be performed to rule out brain diseases and to determine the cause.
Diagnosis
Diagnosis of acute common strabismus
Diagnostic criteria
1. Acute common esotropia: For children with older age who can describe the symptoms of diplopia, intermittent diplopia of adults or the elderly with constant internal obliqueity, the complex imaging distance and eye movement in all directions should be carefully examined. In the case, use the same machine to check the binocular monocular function and the neurological examination to rule out the brain disease. If the above characteristics are available, the diagnosis can be based on the symptoms, but it should be differentiated from the nerve palsy and the convergence.
2. Acute common exotropia: often secondary to brain lesions, diagnosed according to clinical features and neurological examination, but should be differentiated from paralysis and paralysis.
Differential diagnosis
1. Diffusion of paralysis: The clinical manifestations of this disease are similar to those of acute common esotropia. It is characterized by the fact that the two eyes cannot be separated at the convergent position, and esotropia can occur suddenly, and ipsilateral diplopia is present, at 25~ It is obvious outside 35cm, and it can be reduced or disappeared. The complex image does not change according to the rotation of the eyeball to the lateral side. The eye position is normal. The movement of both eyes to the lateral side is normal. Those with combined nerve paralysis can be abducted and restricted. Sexual strabismus is often a single eye with a sudden internal oblique, and no abduction is limited. Some authors believe that abduction paralysis is a central nervous system disease, such as encephalitis, syphilis, multiple sclerosis, head trauma, intracranial mass, increased intracranial pressure, Cerebral hemorrhage and other causes, but acute common esotropia does not have obvious central nervous system disorders, Burian believes that abductive paralysis can also occur in patients without central nervous system or systemic disease, but can still be identified by clinical features.
2. Paralysis of abducens nerve: in the bilateral side of the nerve paralysis, look far and near have a double vision, when the direction of the bilateral paralysis muscles, the complex image spacing becomes larger, and Both eyes are limited in abduction.
3. Convergence spasm: Both eyes may suddenly become over-collected due to excessive convergence, and are fixed at one point, so there is obvious esotropia, which is intermittent, which can occur because the eyes cannot be separated when looking far. The same side double vision, but when you look close, you can't further converge, so there is cross-overlapping, the fusion force is not affected, accompanied by pupil reduction and distance vision loss.
4. Paralysis 0f convergence: The clinical manifestations of this disease are similar to those of acute common exotropia, but the single eye inward rotation of patients with paralysis is normal, but the convergence cannot be performed within 1m distance. And the contraction is weakened, the pupil responds to the light normally, the eye position is normal or mild exotropia, because it can not be convinced, so there can be cross-viewing in 1m, seeing the distant double vision is reduced, and the near-distance complex distance is obviously increased. The upward and downward co-directional movement of both eyes is unobstructed, while the acute common exotropia manifests as constant exotropia. The distance between the far-sighted and the near-looking complex is not changed much, and may be accompanied by upward and downward movement of the eyes.
5. Convergence insufficiency: This disease is more common in the elderly and young women, suffering from chronic diseases of the whole body, physical weakness, fatigue or previous oblique deviation is more likely to occur, the incidence of factors is due to the decline of regulation, presbyopia Eyes wearing presbyopic glasses to reduce the convergence caused by the convergence of the near point is greater than 10cm, depending on the near object is not durable, eye pain, sputum pain, dizziness and back pain and other symptoms of visual fatigue, double vision only occurs when fatigue There is no change in the imaging distance, no horizontal co-directional and up-and-down dyskinesia and pupil abnormalities.
