Childrens’ Eye Health
& Vision Problems
Children with vision problems often do not complain about trouble with their eyes, and many exhibit no outward signs of impairment. Pediatric Ophthalmologist Dr. Robert Kitei specializes in the diagnosis & the treatment of routine and complex children’s eye problems, including crossed eyes (strabismus), lazy eyes (amblyopia), blocked tear ducts, eye infections, cataracts and glaucoma, as well as regular eye care and eyeglass prescriptions. Parts of our office is geared toward children, with entertaining toys and videos. Adults suffering from double vision, crossed or misaligned eyes are also regularly treated, sometimes with special “prism glasses” or with surgery when appropriate.
Strabismus & Crossed Eyes
Strabismus is a misalignment of the eyes. It includes in-turned eyes, called Esotropia, out-turned eyes, called Exotropia and other eye muscle disorders. Because strabismus is treated so often by pediatric ophthalmologists, many pediatric ophthalmologists including Dr. Kitei also treat adults with strabismus. When strabismus occurs in an adult for the first time, it can lead to double vision, or diplopia. Sometimes children are successfully treated for strabismus only to redevelop strabismus later in life. This may be secondary to the inability of a person to use both eyes together, called binocular vision, or other unknown causes. People who have one eye that does not see well when fully corrected with glasses, called Amblyopia, may develop strabismus with time. Most often, the poorer seeing eye will drift outward. In adults who suddenly develop strabismus we must be concerned about vascular insults to a nerve that controls the movement of one or more eye muscles. This is most often seen in adults with a history of diabetes or high blood pressure.
–Types of Strabismus
This form of esotropia, or crossed eyes is also known as infantile esotropia. It usually develops before the child is six months old and is characterized by a large eye turn. Unlike Accommodative esotropia, glasses will not correct the eye turn. Amblyopia is common in children with congenital esotropia and should be treated early. Once the child’s vision is equalized, treatment can be recommended for the eye turn. Eye muscle surgery is the treatment for patients with infantile esotropia. The surgery is usually performed on both eyes, although it may also be done on one eye. The goal of treatment in infantile esotropia is to straighten the eyes so that the child can learn to use them together and develop “binocular vision. The ability to use both eyes together will help to keep them aligned. Studies have shown that early surgical alignment improves the chances of developing binocular vision. Therefore, many pediatric ophthalmologists recommend surgery when the angle of crossing is stable and the vision in each eye is good.
Many children with congenital esotropia develop other eye muscle disorders. This occurs even when their eyes have been successfully made straight with surgery. Recurrent esotropia following surgery for congenital esotropia occurs frequently and often can be treated with glasses and not require further surgery. This is a different type of esotropia than the original infantile crossing. Many patients develop vertical strabismus which can occur months to years after the original surgery. Treatment may require further surgery.
As you can see, infantile esotropia is a complex disorder. Although surgery is required to treat it, it is only the start of the process. These children must be carefully followed for other problems during the visually immature period of their life.
Most children are farsighted. In children, this means that they have the potential to see well at both distance and at near. However, they have to “focus” or accommodate to do so. This is usually not a problem as children have a large “focusing” ability. A reflex exists that makes the eyes want to cross when we try to focus. This normal reflex allows our eyes to maintain alignment when we focus to read material close to us, i.e. our eyes must both turn in a little to work together at near. However, if a child is very farsighted, their eyes will cross when they focus to see well. In this case, they must make a subconscious decision to see well or cross their eyes. The treatment for this type of strabismus is eyeglasses. The child is given glasses to correct their farsightedness. Because they no longer have to focus to see well, they will no longer cross their eyes. Amblyopia is very common in this setting. If Amblyopia is present, in addition to eyeglasses, treatment for the Amblyopia may be required as well. Many children lose some of their farsightedness as they get older and will outgrow their glasses. This is dependent on the initial level of farsightedness and the growth curve of the eye. It is very individualized and therefore it is hard to predict who will outgrow their need for glasses.
Intermittent Exotropia is a type of strabismus where one, or both, eyes turn outward intermittently. It usually begins in the 2-3 year age group. It is first seen infrequently when the child is sick or tired and only when they are looking into the distance. For this reason, in its early stages, it may not be seen in a pediatrician’s office, when the child is examined only up close and is well rested. It generally progresses in frequency and duration with the eye turn occurring earlier in the day and the deviating eye staying out for longer periods of time. Often, the child closes one eye to eliminate the double vision that it may cause. This is especially noticeable in sunlight. As the disorder progresses, the eyes will also start to turn out when looking at close objects as well, i.e. reading. If not treated, the eye may turn out constantly and binocular vision could be lost. Amblyopia can occur in intermittent exotropia but is uncommon.
Amblyopia & Lazy Eye
Amblyopia is the medical term for poor vision in one, or sometimes both eyes. Children are born with poor vision. As they develop the eyes send the message of what they see to the brain and the visual brain cells “learn” how to interpret these images. Over time the brain learns how to fine-tune the images it is receiving and the vision improves. If the image that is being sent to the brain is blurry then the brain will never learn how to see clearly from that eye. The important piece in this problem is that the brain cannot “learn” how to see clearly after a certain age (that age is not known for certain). We do know that the younger the patient is when he/she is treated the better the outcome will be. So, Amblyopia should be treated as early as possible.
-Causes of Amblyopia
The most common forms of amblyopia are strabismic and anisometropic. Strabismic amblyopia occurs when a strabismus is present and the eyes are not aligned. The brain favors one eye over the other and the non-preferred eye is not adequately stimulated and the visual brain cells do not mature normally. Anisometropia refers to the condition when the eyes have an unequal “refractive power”. As an example, one eye may be nearsighted and the other farsighted. Because the brain cannot “balance” this difference, it picks the eye that is “easier” to use and develops a preference for this eye only. Other causes of amblyopia may include: cataracts, ptosis and trauma.
-Treatment of Amblyopia
In most cases Amblyopia is treatable. However, the success of treatment is dependent upon the initial level of vision, the amount of time the vision has been poor and the age of the child. The most important factor in treating Amblyopia is compliance with the treatment protocol. Treatment requires “forcing” the brain to use the non-preferred eye. In most cases this means patching the better seeing eye for some part of the day. Glasses may also be required to “balance” an unequal refractive power between the two eyes. For some patients an eye drop can be used to blur the vision in the better seeing eye. If a cataract is present, this may need to be removed before Amblyopia treatment can be started. The initial treatment period may be difficult for the child, as he/she is being made to use their poorer seeing eye. This usually lasts a short period of time, as their vision usually improves rapidly.
A cataract is an opacification or clouding of the normal crystalline lens. Cataracts can occur at different ages in children. The diagnosis of a congenital cataract which is present at birth can be made on the first day of life if a red reflex is not obtained in the newborn nursery. Early diagnosis and referral are important since irreversible damage can occur if a congenital cataract is not treated in the first few months of life. Congenital cataracts can result from problems with the eye itself or from systemic disorders. Because of this a thorough ocular and systemic evaluation should be performed in any child who presents with a cataract. A genetic evaluation may be indicated in some cases as well.
-Treatment of Pediatric Cataracts
If the cataract is determined to be visually significant, surgery is indicated to remove the involved lens. Once the visual axis is cleared, the child will require optical correction to allow visual rehabilitation. This may include the use of glasses, a contact lens or an intraocular lens implant. Because of the small size of the infant eye, a high power optical correction is necessary, which often cannot be obtained by the use of glasses alone.
Glasses may also not be appropriate in a child following unilateral cataract extraction because of their magnification effect. This can result in difficulty with clarity of vision as well as problems with the development of binocular vision. Because of these factors a contact lens is sometimes used. These contact lenses should not be thought of as a substitute for glasses as they may be in adult patients. They are an absolute necessity for infants with cataracts or an older child with a unilateral Cataract. In some patients an intraocular lens can be implanted. Because of concerns regarding the immaturity and future growth of the infant eye, some surgeons prefer not to implant an intraocular lens in a very young child. Amblyopia is a major obstacle to the development of good vision in these children. Amblyopia therapy is an important issue in the management of childhood cataracts. A good visual outcome is highly dependent on the compliance with amblyopia treatment.
Nasolacrimal Duct Disorders
Tearing in children is a common finding. There are many different causes of tearing and it is important to have your doctor check your child for some of the more serious problems. Most often tearing is caused by a blockage of the nasolacrimal duct (NLD) passageway. This is a common finding in infants-studies have shown that about 6% of infants are born with an NLD obstruction. The most common cause of an obstruction is from a mucous membrane of the nose, which fails to regress during development. Other causes of NLD obstructions include irregular development of the lacrimal drainage passageway, infections, trauma, growths and medications. Treatment initially involves massaging the lacrimal system, warm compresses and sometimes antibiotic drops. If these interventions are unsuccessful, a nasolacrimal duct probing may be necessary. Some children require the placement of a silicone tube in the nasolacrimal duct system to keep the passageway open. Most obstructions will resolve on their own by one year of age. However, some children have severe symptoms and require intervention before this age.