Today’s guest blogger is Dr. Marie Bodack. Dr. Bodack is a pediatric optometrist at the Cincinnati Children’s Hospital. She has published numerous articles on children’s vision, including this one on pediatric acquired brain injury.
Strabismus or “crossed eyes” is a common childhood eye disorder and has been reported to affect 2-5% of school aged children. Often, parents, and sometimes, pediatricians, do not understand strabismus. This post summarizes some of the key points of strabismus.
S – Symptomless – Strabismus can be symptomless for the child. A child will not often be able to tell a parent that “my eye is turning in (or out).” When the eye is turning, the brain has the ability to “shut off” that eye, so the child will still be able to see with the eye that is straight or the “better’ eye. Since a child has 2 hands and usually favors one, it is not surprising that a child will not tell a parent that one eye works better than the other. In almost all cases, strabismus is detected by a parent or another adult when looking at the child.
T – Therapy can be a treatment for some forms of strabismus. Vision therapy, or orthoptics, is a program designed to help maintain eye alignment, focusing, tracking and to develop the use of both eyes together (stereopsis or binocularity). Therapy can be geared to the child’s age and can incorporate techniques using glasses with colored lenses, 3-D targets, computer programs and eye hand coordination projects, to name a few.
R – Right eye, left eye or alternating eyes. In some cases strabismus can be monocular and affect only one eye, either the right or the left. In other cases, the strabismus can affect both eyes, such that sometimes the right eye turns and sometimes the left eye turns.
A – Anatomy. Sometimes a child may look like the eyes are crossing but in reality they are not. This is known as pseudo strabismus, and is due to the anatomy of the eye position – the distance between the eyes, the eye lid folds and the structure of the bones around the eye. This is more noticeable when children are infants. Over time, as the facial structures mature, the pseudo eye turn will be less noticeable.
B – Binocularity. Binocularity is the ability to see 3-D. When somebody has a strabismus and the eyes are both not looking straight, the person will not have good binocularity. This will affect the ability to see 3-D. The next time you are in a 3-D movie, close one eye and you will notice that the movie looks different. People with strabismus cannot see the “popping out” that people without strabismus can see. Binocularity is important for many tasks we do: catching a ball, walking down stairs, driving a car and stopping it and threading a needle. Certain professions such as an airline pilot also require good stereopsis.
I – Intermittent. Strabismus can be constant – one eye is turned all the time, or intermittent. If the eye turn is intermittent it will not always be present. Sometimes it is more noticeable when a child looks at a certain distance (either far or near) or when a child is tired or ill.
S – Symptoms. Sometimes children with strabismus may complain of seeing double – 2 images either side by side or up and down. Often, if the strabismus is intermittent, patients may have symptoms when the eyes turn and no symptoms when the eyes are straight. Sometimes, if a child is wearing glasses, the symptoms can indicate that the glasses need to be updated. In other cases, double vision can be a sign of a neurological problem.
M – Movement. In strabismus the eye can move (or turn) in different directions. An eye that turns in to the nose is known as esotropia. An eye that turns out to the ears is known as exotropia. An eye can also turn up or down which is less common. An eye that turns up is known as hypertropia, while one that turns down is known as hypotropia.
U – Unique Forms. There are some different forms of strabismus that can be associated with unique eye or medical findings. Conditions such as Duane’s Syndrome – where one eye does not move as well as the other eye, or Brown’s syndrome, where one eye does not elevate as well as the other eye in certain fields of gaze are two examples. Additionally, patients who suffer a brain injury can also develop a strabismus. Patients with some medical problems, such as thyroid problems and multiple sclerosis can develop strabismus also. In other cases, especially if there are other signs such as headaches, a strabismus can indicate a problem with the brain.
S – Surgery. Surgery can be an option for certain forms of strabismus, especially for very large sizes or more complicated cases. Often, surgery, in combination with vision therapy can result in the best outcome for the patient in terms of developing binocularity and improved vision.