The human eyes are able to rotate freely up and down, left and right together, depending on the close cooperation and coordination of the six muscles that pull on the wall of each eye in order to restrain each other. If the contraction of one of these muscles is too strong or too weak and cannot be balanced with the strength of the muscles that oppose it, it will cause strabismus. In addition, strabismus can also occur if one or more of the extraocular muscles are paralyzed, or if there is a congenital developmental abnormality, or if the nerve center in the brain that governs eye movements is dysfunctional.
What types of strabismus are there
1.Common strabismus
According to whether it can be controlled by the fusion reflex, it is further divided into cryptorchidism, common internal strabismus, and common external strabismus.
2.Non-common strabismus
Also called paralytic strabismus, it is a strabismus caused by paralysis of the nerve or muscle innervating the eye.
3.Horizontal strabismus
Also known as A-V syndrome, it is a subtype of horizontal strabismus. Since it is accompanied by vertical paralysis, the size of the horizontal strabismus changes significantly when gazing upward and downward, just like the shape of the English alphabet, hence the name A-V syndrome.
What is a contralateral eye
Internal strabismus, commonly known as contralateral eye, is a condition in which one eye is squinted to the nasal side while the other is squinted to the nasal side, and is very common in children aged 2-3 years. Some of them are related to refractive state and adjustment, such as children with moderate or high hyperopia, who are not corrected for farsightedness and can only see clearly by using too much adjustment, thus inducing too much convergence (convergence of both eyes inward) and causing internal strabismus. Others are related to imbalance of extraocular muscle strength.
What is strabismus?
Exotropia, commonly known as strabismus, is a condition in which one eye looks outward while the other looks inward. There are several common causes.
1, uncorrected myopia, due to the use of regulation to reduce the use of regulation set and cause exotropia.
2. Highly farsighted people who give up regulation because they cannot see well also have exotropia.
3, refractive error, because of the difference between the two eyes, the brain inhibits the eye with poor vision and causes the eye to be disuse exotropia.
How to treat strabismus
Different types of strabismus are treated in different ways. Generally speaking, common strabismus should be treated by dilating the pupil and wearing appropriate glasses to correct the refractive error. Mild strabismus only requires correction of refractive error to correct the eye position. In the case of primary strabismus, which is not related to refractive error, if the strabismus cannot be corrected after wearing glasses, surgery must be performed in time, and the younger the age of surgery, the better. The reason is that only when the eye position is corrected before the establishment of monocular function in both eyes, and after the auxiliary training, the future can have good synoptic perception, fusion and stereo vision. The treatment of non-concurrent strabismus should first find the cause and then provide comprehensive treatment for different causes.
Can the opposite eye heal itself?
Primary internal strabismus is caused by an imbalance between the internal and external rectus muscles and cannot be cured by itself.
Secondary internal strabismus is caused by hyperopia. If the degree of hyperopia is small, the internal strabismus will gradually improve or even return to normal as the age increases.
You should go to the ophthalmology department in time to find out the internal strabismus, do not indulge in its development, so as not to miss the time of treatment.
What is pseudo-intraocular strabismus
Some parents find that their child has an eye strabismus, and when they take the child to the hospital for an examination, the doctor says the child’s eyes are normal. What is this? In fact, this is pseudo-internal obliquity, also known as medial canthus, which is more common in Asian children, and nearly half of the children in China have medial canthus. In these children, the upper eyelid covers part of the white of the eye on the side of the nose because of the flat nasal bridge, creating the illusion of an internal strabismus, which disappears as the nasal bridge gradually rises with age.
Treating strabismus or amblyopia first
Generally speaking, if you have amblyopia in one eye and strabismus that requires surgery, you should treat the amblyopia first. When the corrected visual acuity of the amblyopic eye is improved to about the same level as the other eye, the strabismic eye should be treated surgically, which is conducive to the recovery and stabilization of monocular vision in both eyes.
If the amblyopia is bilateral, it should be treated first, so that the corrected visual acuity of both eyes is about the same, and then the strabismus should be treated surgically.
In the case of secondary strabismus, surgical correction is not required, and amblyopia treatment must be carried out at the same time as wearing glasses for strabismus.