Peadiatric / squint

What is a Pediatric Ophthalmologist?

Pediatric ophthalmologists are medical and surgical doctors who specialize in the eye problems of children. In particular, vision develops in the brain until about age 9 years and can be affected by eyes that are not straight or do not focus correctly. A child can grow up with good vision in each eye if these problems are caught early, treated and maintained.

All ophthalmologists have some training in children’s eye problems, but the pediatric ophthalmologist has had additional training and practice in examining children and caring for their eye problems. If your primary care doctor suggests that your child have his or her eyes checked, a pediatric ophthalmologist will have the greatest knowledge of the possible conditions and the greatest experience in examining children effectively.

•Vision Screening
Vision screening is aimed at detecting eye disorders of children which are amenable to treatment in the early years of life.

When a child is young, the visual system continues to mature. Treatment options which may be very effective during a child's early years may offer little or no benefit later in life. For this reason, early awareness of eye care and health certainly can make a difference.

•Eye Exams

What can you expect when you take your child to the ophthalmologist?
An assessment of vision is the first step. Each eye will be checked separately. This is important because a child can function normally even if one eye is blind, provided that the other eye sees well. Before the child is able to cooperate with reading an eye chart, the fixation behavior of each eye on various toys or objects can be evaluated. The doctor will also check that the eyes are aligned (i.e., that is there is no strabismus). Strabismus refers to the condition where two eyes do not point in the same direction, such as with crossed eyes. The health of the front portion of the eyes and reactions of the pupils to light will also be checked.

The next step is usually to dilate the pupils. One or two eye drops are placed in each eye and after 20-30 minutes the pupils are dilated and the muscles inside the eye are relaxed. This enables the doctor to assess for cataracts and to view the retina (which is the nerve tissue in the back of the eye). Even in children unable to speak, the ability of the eye to focus normally can be assessed with the use of several highly accurate instruments. This will help determine if the child needs glasses. After the exam, the pupils will remain dilated for several hours. This may result in some mild blurring of near vision as well as sensitivity to sunlight.

•Eye Glasses
Eye glass prescriptions are given to children for a variety of reasons. A common reason is to improve vision. Glasses accomplish this simply by focusing images clearly onto the retina in the back of the eye.

Myopia or nearsightedness, which refers to difficulty seeing in the distance, is one of the most common conditions requiring glasses. Myopia typically appears around the age of nine or ten and in its early stages often does not need correction. The usual course, however, regardless of whether glasses are prescribed initially, is for the myopia to increase as the child grows. The onset and the final level of nearsightedness are hereditary to some degree.

Astigmatism refers to the eye being out of focus because the cornea or the front surface of the eye is not perfectly shaped. Glasses can easily compensate for this distortion and are prescribed based on the amount of astigmatism and the age of the child.

Hyperopia or farsightedness is another condition which may require glasses. Whereas hyperopia in adults may cause blurring, some amount of hyperopia is actually a normal finding in children. Unless the amount of hyperopia is very high, children's eyes can focus clearly despite hyperopia. Therefore, glasses may not be necessary. This is not the case, however, if the farsightedness is associated with crossing of the eyes ( Accommodative Esotropia). In that situation, farsighted glasses would be required to maintain straight alignment of the eyes.

Another reason to prescribe glasses is to treat amblyopia or a "lazy eye." Amblyopia is a condition where the vision pathways between the eye and the brain do not develop fully because one or both eyes do not receive the proper visual stimulation. One cause for this is one eye being out of focus in relation to the other. For example one eye may have astigmatism while the other does not. In this instance, vision would be clear with both eyes open because one eye is perfectly focused. Glasses, therefore, would be needed to prevent or treat the amblyopia in the eye which is out of focus.

What is "farsightedness"?
The optical system of the eye focuses the image behind the retina rather than on the retina. Young eyes have the ability to bring the image forward and focus it on the retina. Children under the age of 8 are normally mildly farsighted.

What is "nearsightedness"?
Myopia or nearsightedness occurs when the optical system of the eye focuses the image in the front of the retina rather than on the retina. This can only be corrected with glasses.

My child's eyes look crossed. What should I do?
Crossing or wandering of the eyes should be evaluated right away. If it is noted in infancy, surgery may be warranted. If it is noted for the first time in a toddler, glasses may help in some cases. In all instances, one should see a pediatric ophthalmologist to rule out ambylopia or other pathogenic conditions.

What is "amblyopia"?
Amblyopia (Lazy Eye) is the inability to see clearly out of an eye that is otherwise sound. It is due to miswiring between the eye and the brain and can lead to permanent reduction of visual acuity unless treated in early childhood.

What causes amblyopia?
Amblyopia may be caused by any condition that affects normal visual development or use of the eyes. Amblyopia can be caused by strabismus, an imbalance in the positioning of the two eyes. Strabismus can cause the eyes to cross in (esotropia) or turn out (exotropia). Sometimes amblyopia is caused when one eye is more nearsighted, farsighted, or astigmatic than the other eye. Occasionally, amblyopia is caused by other eye conditions such as cataract.

How is amblyopia treated in children?
Amblyopia treatment is most effective when done early in the child's life, usually before age 7. Treating amblyopia involves making the child use the eye with the reduced vision (weaker eye). Currently, there are two ways used to do this:

•Atropine
A drop of a drug called atropine is placed in the stronger eye once a day to temporarily blur the vision so that the child will prefer to use the eye with amblyopia. Treatment with atropine also stimulates vision in the weaker eye and helps the part of the brain that manages vision develop more completely.

•Patching
An opaque, adhesive patch is worn over the stronger eye for weeks to months. This therapy forces the child to use the eye with amblyopia. Patching stimulates vision in the weaker eye and helps the part of the brain that manages vision develop more completely.

Why does a child need glasses?
Children may need glasses for several reasons—some of which are different than for adults. Because a child’s vision system is growing and developing, especially during the first 5-6 years of life, glasses may play an important role in insuring normal vision development. The main reasons a child may need glasses are:

1. To provide better vision, so that a child may function better in his/her environment

2. To help straighten the eyes when they are crossed or misaligned (strabismus)

3. To help strengthen the vision of a weak eye (amblyopia or “lazy eye”). This may occur when there is a difference in prescription between the two eyes (anisometropia). For example, one eye may be normal, while the other eye may have a significant need for glasses caused by near-sightedness, far-sightedness or astigmatism.

4. To provide protection for one eye if the other eye has poor vision

I am an adult with double vision. What can I do?
Double vision in adults needs to be evaluated to rule out a neurologic cause for the condition Once the cause is evaluated, it can be treated with prisms, surgery or a full-time patch

Cataract
What is a cataract?
A cataract is any cloudiness or opacity of the normally clear lens of the eye. Cataract size ranges from very small to entire lens involvement.

How common are infantile and childhood cataract?
About 3 children per 10,000 children have a cataract. The incidence is variable throughout the world.

How does a cataract cause vision loss?
A cataract causes decreased vision by interfering with the light ray path to the retina (back part of the eye). Abnormal vision development resulting in a lazy eye (amblyopia) can occur when a child has a cataract.

Why are some babies born with a cataract?
Pediatric cataracts often occur because of abnormal lens development during gestation. Lens malformations that occur in conjunction with other findings are often the result of a genetic or metabolic abnormality. These cataracts may be present at birth or develop during childhood. However, most pediatric cataracts are not associated with other abnormalities.

Do all cataracts in babies and children need to be removed?
No. Some cataracts are small and/or off-center in the lens. These cataracts do not need to be removed because vision develops normally, even if the cataract is left in place.

At what age should a cataract be removed from an infant or child?
Cataracts that cause significant visual loss are typically removed as soon as is safely possible. The visual part of the brain very actively develops during infancy and childhood. If a cataract causes a blurred picture, the visual part of the brain does not develop normally and causes amblyopia. A visually significant cataract should be removed and vision rehabilitated before the brain reaches visual maturity. This often involves patching an eye.
Children may require an additional opening in the posterior lens capsule with some vitreous gel removal. An intraocular lens is then sometimes placed within the lens capsule. Lastly, the incisions are closed.

STRABISMUS / SQUINT
What is strabismus?
Strabismus is a medical term for any misalignment of the eyes

Are there different types of strabismus and if so, how are they named?
Yes, there are different types of strabismus.
Strabismus is most commonly described by the direction of the eye misalignment; esotropia, exotropia, hypotropia, and hypertropia

What causes strabismus?
Most strabismus is caused by an abnormality of the poorly understood neuromuscular (including brain) control of the eye movements. Less commonly, a problem with the eye muscles themselves causes strabismus.

How is strabismus related to amblyopia?
Eye misalignment can cause amblyopia in children. When the eyes are looking in different directions, the brain receives 2 different visual images. The brain ignores the image from the misaligned eye to avoid double vision, resulting in poor vision development.

Can poor vision cause strabismus?
Yes. An eye that sees poorly tends to wander.

Who develops strabismus as a child?
Any child can have strabismus. However, disorders that affect the brain such as cerebral palsy, Down syndrome, hydrocephalus and brain tumor are associated with an increased incidence of strabismus.

What adult disorders cause strabismus?
Stroke is the leading cause of strabismus in adults. Trauma, brain tumors and Graves disease (thyroid eye disorders) are other common causes of strabismus.

How does trauma cause strabismus?
Trauma can cause strabismus by 1) damage of the brain thus impairing control of eye movement, 2) damage of the nerves that control eye movement and/or 3) damage of the eye muscles either directly or secondarily from trauma of the eye socket.

How is strabismus treated?
The goal of strabismus treatment is to straighten the eyes and allow the eyes to be used together (binocular vision). Treatment may involve eye glasses (glasses for children), eye exercises and/ or eye muscle surgery (strabismus surgery).