PEDIATRIC EYE EXAMS
Why are Pediatric Eye Exams Important?
5-10% of preschoolers and 25% of school-aged children have vision problems. Early identification of a child's vision problem(s) is crucial because children are often more responsive to treatment when diagnosed early.
According to the American Optometric Association (AOA), infants should have their first comprehensive eye exam at six months of age. Subsequent eye exams should occur at three years of age, and just before they enter kindergarten or the first grade at about age five or six. For school-aged children, the AOA recommends an eye exam every two years if no vision correction is required. Children who need eyeglasses or contact lenses should be examined annually or according to eye doctor recommendations.
Early eye exams also are important because children need the following basic skills related to good eyesight for learning:
Binocular (two eyes) coordination
Eye movement skills
When scheduling an eye exam for your child, make sure to choose a time when he or she is usually alert and happy. Pediatric Eye examinations vary depending on the age of your child, but may include:
A visual acuity or refraction test to determine the degree to which your child may be nearsighted, farsighted or have astigmatism.
A longer-acting dilation drop to objectively determine your child’s refractive error. This longer acting drop (cycloplegia) can be an important part of the exam, and takes 30-40 minutes to take effect before the doctor may examine your child. Please schedule your child’s eye examination with this in mind.
AMBLYOPIA & STRABISMUS
What is Amblyopia?
Amblyopia is also known as a lazy eye. It is a condition, usually found in children, in which one or both eyes do not develop properly. An easy way to explain this is that the "eye-brain" connection does not communicate properly; therefore, the child does not know what clear vision is...or what 20/20 vision is. The eye anatomy itself is normal, but the neural pathway to the brain is not normal, causing decreased vision.
Prevalence of Amblyopia
Amblyopia is one of the most common treatable forms of vision impairment in children. Its prevalence is as high as 3-5% in some studies. It is most common in infants and young children and it is imperative that this condition is caught early. The chance of successful vision restoration goes down dramatically after age 8, therefore the earlier this condition is caught the better chance of successful treatment.
Causes of Amblyopia
The causes of amblyopia are varied. A very common condition that can cause amblyopia is strabismus, a misalignment of the eyes. This occurs when one eye has an abnormal turning in or out, causing the brain to stop using the misaligned eye. Other causes may come from a high prescription such as nearsightedness, farsightedness, or astigmatism. In the case of these conditions, the eye’s vision is out of focus and so the brain turns off that image. Eye disease processes can also cause amblyopia. One of these conditions is known as a cataract. A cataract is a condition of the lens of the eye developing an opacity so that light cannot pass through. Abnormal retinal conditions and hereditary factors can also cause amblyopia.
Treatment of Amblyopia
In order to increase the chances of success, this condition must be detected early. The recommended ages for early eye examination are 6 months old, then 2-3 years of age, and then school age. There are several different forms of treatment for amblyopia, which are explored below.
Patching, or occlusion therapy. One of the most common treatments for amblyopia is patching, also known as occluding, the better or stronger eye. This forces the brain to use the weaker eye. An adhesive eyepatch on the skin or a slip-on patch over glasses can be incorporated for occlusion therapy. A blurring contact lens or dilating eye drop can also be used to occlude the good eye.
Surgery. Cataract, eye muscle, or retinal surgery can be incorporated to help treat the underlying cause of amblyopia in some cases.
Vision therapy. Vision therapy has been proven to be successful in the treatment of amblyopia. Vision therapy, or VT, incorporates a series of vision training procedures that help improve eye movement control, visual acuity, depth perception, and eye coordination. Vision therapy can be done in an office or home setting.
Signs and Symptoms of Amblyopia
The most common way amblyopia is diagnosed is a detection of a decreased red reflex in the child's eye. A diagnostic instrument used by the optometrist, ophthalmologist, or pediatrician, can pick up a bright reflection in the normal eye and a dim reflection in the amblyopic eye. Upon further examination, the eye is dilated to see if a refractive error of myopia, astigmatism, or hyperopia is the cause.
Another sign of amblyopia is an eye that turns in or out. A symptom that may be indicative of amblyopia is if the child prefers the vision out of one eye. This can sometimes be detected when occluding the better eye— the child may become fussy and upset because she cannot see out of the lazy eye.
VISION & LEARNING
My Child Is Near-Sighted. Will Glasses Correct Their Learning Problem?
There is controversy over the exact relationship between vision and learning. For example, there is a negative correlation between distance refractive error and reading ability. Myopic or nearsighted children who cannot see clearly at a distance without glasses are more commonly good readers. Children who spend tremendous amounts of time reading become nearsighted. Before Alaska became a state myopia was rare. After becoming a state, more than 50 percent of the children in Alaska developed nearsightedness. Thus, correlation is such that nearsightedness or poor distance vision is highly correlated with success in reading. Restated another way, poor distance vision is associated with better reading abilities. Farsighted children statistically are poorer readers than myopic children.
What is the Relationship Between Eye Muscle Problems and Learning?
Some of the mechanical visual skills which are related to reading include focusing or accommodation, and eye teaming, or convergence. Fatigue of one or both of these systems may interfere with reading. There is also a relationship between eye movements such as saccades (whereby we change fixation from one target to the next) and smooth following movements known as pursuits and reading. Children who cannot make accurate eye movements are often found to skip lines and words while reading.
The visual system was originally designed so that the peripheral vision was responsive to motion detection (danger from the jungles) with a central portion for fine discrimination (to identify the source of danger; e.g., a lion.) In the school environment, the child is expected to ignore the peripheral portion of their visual system and pay attention to the central portion. If the child can not ignore the peripheral portion, he/she becomes distracted. Improvement in eye movement skills often results in less distraction and fewer errors in skipping words while reading.
My Child Loses Their Place. Is That Related to the Eyes?
Reading requires very accurate saccades, which are fixations from one spot to another. Children who have poor eye movements are easily distracted and lose their place. Remember, the eye movement system was designed so that peripheral vision detects motion and danger. Imagine what happens when the system works correctly in the classroom. As soon as there is peripheral movement, the eyes move toward the source of movement. This results in the complaint of inattention. Thus, reflexive eye movement skills must be socialized so that they do not respond reflexively to peripheral information. In addition, speed and accuracy must be trained so that one does not lose one’s place.
The skills are easily improvable with vision therapy. Once the information is brought into the eyes, it must be sent back to the brain for appropriate processing. The information must be utilized and integrated with the sensory and motor areas of the brain. Defects in the perceptual (interpretation of visual system) and motor (the integration with output, e.g., hand-eye coordination) may interfere with the reading process. Perceptual motor skills are key in the early acquisition of reading skills. A deficit is important to identify very early on-- i.e., five to seven years of age. Remediation of the skills at a later date, such as age 12, will be less effective for reading. Thus, early identification and treatment are essential. It is evident that there is more to good vision than 20/20.
My Child Reverses Letters and Words. Do They See Backwards?
It has been presumed that children who reverse letters or words see them backward. This is false. They have directional confusion. In the real world, the direction has no meaning. For example, a chair is a chair no matter which way it is placed. Changing direction does not change interpretation. In the world of language, direction changes meaning. Connect the bottom of a chair and it looks like a "b". Turn it 180 degrees it becomes a "d", flip it upside down and it becomes a "q" and flip it again it becomes a "p". Thus, direction changes the meaning. The difference between "was" and "saw" is the direction.
What Are the Other Visual Components Necessary for Academic Achievement?
As mentioned previously, we should correct all optical errors of the eyes (glasses); eliminate eye muscle problems; and create smooth accurate eye movements. In addition, we should make sure that we properly interpret what we see and use it appropriately. These are known collectively as perceptual skills and include form perception, size and shape recognition, visual memory, and visual-motor integration (hand-eye coordination.)