Strabismus is a common condition that is defined as a state in which the eye turns or deviates when looking at a single object of interest. In simple terms, strabismus is a condition where both eyes do not coordinate or look at the same object at the same time.
Strabismus occurs when the eyes turn up down, in out and it is because of poor eye muscle coordination. Crossed eye is very common in newborn babies, which they tend to grow out from. However, if the infant is 3 months old or if the infant looks with one eye closed or turns his head towards one side while looking at a particular object, parents should immediately report their child to doctor.
If strabismus is noticed all the time, it is called as constant strabismus; if it is noticed only sometime then it is called intermittent strabismus. It is said to affect 4% of children below 6 years of age.
For both the eye to align normally and look at the same object at the same time, there are 6 muscles attached to each eye, which function together to control the movement of the eye. The brain sends signal to these muscles and control their movement.
People suffering with strabismus, all these muscles do not work together, therefore, when one eye is looking at an object the other eye turns towards another object. In such case, a double vision is sent to the brain, initially the brain gets confused, and overtime it starts to ignore the image from the weaker eye. Other predicted causes of strabismus are;
Family history, if one of the parent or sibling has strabismus then the risk increases for the next kid
Refractive error, long-term un-corrected far-sightedness
Kids with Down syndrome and cerebral palsy who have suffered stroke or head injury might develop strabismus
Diabetes can cause acquired paralytic strabismus
High blood pressure
Retinal damage in pre-mature babies
Injury to eye
Tumor in brain or eye
Loss of vision due to disease or injury
Symptoms of strabismus can be noticed either round the clock or only when the kid is tired or sick.
The child may have crossed eye, which do not move together or misaligned eyes.
The child may complain of double vision or reduced vision.
The parents may notice that the child lacks depth perception, and blinks or squints often in bright sunlight.
They may also notice that the child tilts his head to one side while looking at an object.
Physical examination and previous medical history is examined to check the alignment of both the eye.
The doctor also asks for symptoms that parents observe, any other medical condition, any medications taken recently or environmental factors that may have contributed to the condition.
Visual acuity test is done to determine the extent to which the vision is damaged.
Refraction test may be conducted to check the range of refraction (far-sightedness & nearsightedness) and to determine the appropriate power of lens needed to correct any refractive error.
Alignment and focus testing assesses how focused and aligned the eyes moves. This test will focus on looking for the exact problem that is keeping the eye from working in unison.
A test called cover-uncover may be done. It is performed by making the kid look at a particular object, while the doctor observes his eye movement by covering and uncovering the object. The eye structure will be studied to rule out any other problem that is causing strabismus. Both internal and external eye will be assessed.
Children with strabismus have several options to correct their crossed-eye.
Contact lens or eye glasses may be prescribed for kids with uncorrected far-sightedness. Wearing glass may help them to focus effortlessly and this may alone correct strabismus in many. Prism lenses are special type of glasses that reduces the amount of light entering the eyes, and it reduces the amount of turning the eye does while looking at an object.
Vision therapy is a visual activity program that improves eye co-ordination and focusing ability. It trains the eye and brain to work efficiently together.
Strabismus surgery is done to correct the length and position of the eye muscle for better alignment. After a surgery a vision therapy may be required to improve eye co-ordination.
As in every health complication same is the case with strabismus, the early the strabismus treatment starts the easier it is to fix the problem. Usually treatment for correcting the eye may go on for many years, requiring less eye drops as time goes by. Sometimes, single surgery may not correct the problem.
The kid may require many surgeries. As the treatment focuses on aiming the weaker eye to work effectively to have a proper vision, it is very important that parents learn every step to take care of the kid and follow doctor’s instruction carefully.
As said above for a normal vision it is important that both the eye concentrates on the same object at the same time, but in strabismus each eye focuses on different objects and sends two images to the brain, initially the brain gets confused but later it ignores the image from the weaker eye.
If this continuous and is not fixed when the child is young, then it might result in a condition called as amblyopia, a type of vision loss where the brain starts to always reject images from the weaker eye.