Strabismus is a state of separation of the visual axis, that is, when the two eyes look at a target, one eye looks at the target, and the other eye deviates to the side of the target. The reason is the abnormal development of the extraocular muscles, the imbalance between regulation and convergence force, and the incomplete central fusion function, which makes both eyes spread out or converge out of control, resulting in strabismus. If the eye is deviated to the medial side (i.e., nasal side), it is called internal strabismus, and if it is deviated to the lateral side, it is called exotropia (strabismus). Upward or downward strabismus is called superior strabismus or inferior strabismus. Strabismus is fixed only in one eye, called constant strabismus; while some people can alternately gaze at both eyes, the other eye to one side, called alternate strabismus; there are people who usually do not see strabismus, when the concentration or fatigue strabismus, called intermittent strabismus, its harm and constant strabismus the same, and can develop into a constant strabismus. The classification of strabismus can be divided into common strabismus, paralytic strabismus and special types of strabismus (e.g. A-V syndrome, retro-ocular syndrome, detached vertical deviation, etc.). For children, common strabismus is the most common strabismus, especially common internal strabismus is the most common strabismus. I. Timing of surgery for children with strabismus Infancy is a critical period for vision formation, and if early strabismus is not corrected in time, it often leads to severe amblyopia or lack of stereopsis. However, if the surgery is performed too early, it is worried that the child is too small and the risk of surgery will be increased due to the low tolerance of general anesthesia and surgery; the softness of the infant’s eye and the thin sclera increase the difficulty of surgery, and the inability of the child to cooperate with the strabismus detection and the inability to accurately measure the strabismus directly affects the effect of surgery. The current domestic concept is that surgery should be performed early during the plastic stage of visual development (2-5 years old), especially if the following conditions are present: (1) constant strabismus; (2) non-modulated strabismus (uncorrectable with glasses); (3) congenital strabismus; (4) good visual acuity in both eyes; (5) abnormal retinal correspondence; (6) large strabismus; and (7) no contraindications to general anesthesia or history of drug allergy. In several cases, it is best to wait until the time is ripe before performing surgery: ① intermittent strabismus, ② regulatory strabismus, ③ acquired strabismus, ④ monocular or binocular amblyopia, ⑤ normal retinal correspondence, ⑥ small degree strabismus, etc. The director of the center is the president of the National Association of Pediatric Ophthalmology, and is a world authority in the treatment of strabismus in children. We have had more exchanges on the timing of strabismus surgery in children. In the United States, experts believe that the earlier surgery is performed for congenital strabismus, the better, because early surgery can restore binocular monocularity and prevent the development of severe strabismic amblyopia; while for strabismus that develops later in infancy, they advocate that the first surgery be done within 18-24 months after birth. Surgery for strabismus in children is not a simple cosmetic surgery, but a need for early restoration of normal visual function. After the age of 5, children’s stereo vision has formed, and it is often difficult to fully restore their visual function if strabismus surgery is performed afterwards, which is the reason why American experts recommend early surgery. However, in the United States, children with strabismus usually undergo 2-3 (average of 2.86) strabismus surgeries to fully correct the problem. The main reason for this is that the degree of strabismus in children is difficult to determine precisely, so the success rate of one surgery is low. Measurement of strabismus in children There are many methods for strabismus detection, but they are summarized as follows;1 examination of eye muscle movement (masking experiment, corneal reflection method, synoptic machine determination, anisotropic movement detection, detection of modulating collection and adjustment, compensatory head position analysis, Bieschowsky head position experiment, Parks method to detect vertical muscle paralysis, passive pulling experiment and active contraction test, etc.), 2 subjective methods for strabismus (Maddox bar test, red and green ophthalmoscope test, double Maddox bar test, etc.), and 3 binocular visual function test (red glass test, Worth four-point test, trigeminal lens test, Bagolini light bar lens test, stereopsis test, etc.). Unfortunately, however, most of the above methods are only applicable to adults or older children, but are often futile for children under 3 years of age due to their inability to cooperate with the examination. We had invited one of the top pediatric ophthalmologists in India to the ophthalmology department of Guangzhou Children’s Hospital for pediatric strabismus surgery. He was very stubborn that a trigonometry test should be done to determine the degree of strabismus (this method is very important in the diagnosis of adult strabismus), and considering the face of the international expert, we prepared some older children (around 5 years old, we thought the strabismus examination might be easier), and he gave He gave the children a long preoperative trigeminal test and finally completed the surgery. I remember that after the surgery he was very satisfied with the result and kept saying “very good”, but the parents were not satisfied because the children had more or less strabismus after the surgery, so we did not dare to ask Indian specialists to perform strabismus surgery on children for a long time, even if they were very famous Professor. I think the reason for this is that they did not have a good grasp of the preoperative measurement of strabismus in children. It is also very important for children to have their visual acuity evaluated before strabismus surgery. If there is a significant visual impairment in the strabismic eye, the postoperative recurrence rate is higher. Therefore, the first step is to determine the child’s visual acuity. Commonly used methods include optokinetic nystagmus test, selective viewing method examination, and visual evoked potentials. Even these methods are very difficult for smaller children, and their prognostic results often depend on the experience of the doctor. Third, strabismus examination under computer With the development of modern civilization, cameras are becoming more and more popular in families, and more and more children like to take pictures. We found that almost all children do not resist to take pictures, even those with cerebral palsy or autism. Based on the above, we use a high-definition camera to capture photos of the child’s eyes in nine directions and input them into the computer. We use special software to calculate the degree of strabismus based on its corneal reflection (the effect of the kappa angle must be removed), and then use this as the basis for designing a surgical plan, whether for a child with a large strabismus or a child with a small strabismus; whether for a child who can cooperate with the examination or for a child with mental retardation or cerebral palsy. In the past 5 years, we have completed nearly 500 cases of strabismus surgery, and after the surgery, the children were treated with the same vision machine when they were 4 years old, and the success rate of one surgery was over 90%. First, strabismus surgery for children is not a cosmetic surgery, but to restore the balance of both eyes as early as possible to obtain normal stereopsis, so there is a certain time for surgery, do not delay. Secondly, children’s eyes are relatively small, so their strabismus surgery volume is slightly smaller than that of adults, especially children within 1 year old, and the age and developmental factors should be fully considered when designing the surgery volume. Again, children are sensitive to ocular trauma after surgery, so try to perform minimally invasive surgery under a microscope and close the conjunctival incision with 8-0 absorbable sutures. In addition, surgery is not the goal, the key is to restore the visual function of children, so for refractive adjustment strabismus, try to observe with glasses for about six months first, if the eye position can be corrected, it is not necessary to do surgery. Finally, the self-esteem of children should be fully taken into account, so children with strabismus should be patient in their visual acuity check and degree measurement, and at the same time, more encouragement and praise should be given to children.