As I mentioned in my previous post, up to 15% of children between the ages of 3 and 5 have an eye or vision condition that can result in reduced vision if not corrected. The basic vision screenings done at the pediatrician’s office often miss these problems. Despite what many people think, a child doesn’t need to know the alphabet, or even talk, to have a comprehensive eye examination. Obviously, we don’t use a phoropter and ask an infant “which is better, 1 or 2”, but you’d be surprised at how much we can tell about an infant or young child’s vision without a verbal response from the child.
The history is a critical part of the exam. Is there any family history of early childhood problems such as congenital cataracts, amblyopia, strabismus, very high refractive error or retinoblastoma that put the child at greater risk for problems? Were there any problems during the pregnancy, labor or delivery? Is the child reaching developmental milestones on time? Since vision is involved in almost all activities, developmental delays could be a sign of a visual problem.
We have several ways to determine if a child is seeing well. With infants and very young children we are concerned about large differences between the two eyes. If covering one eye bothers them, but covering the other eye doesn’t, one eye may be seeing much better than the other. Preferential looking is another option. Given a choice between a plain target and stripes or a picture of a face; infants will prefer to look at the more interesting target IF they can see the details in it. By watching their preference for targets with details of various sizes, we can get an actual measure of their acuity. In toddlers and young children, we can use picture charts instead of letters and/or hold a “key” card up close where they can point to the picture or letter that they see on the chart farther away.
We can check muscle function by having a child follow a light or small toy and watching how the eyes move when one eye is covered at a time. If they can respond to a 3D test of stereopsis we know there is no major difference in prescription between the two eyes, both eyes have relatively good vision and they are lined up properly. Seeing when the child reacts to an object brought into their view gives us an idea of their peripheral vision. We can check their pupils for signs of neurological problems.
The red reflex is probably one of the most useful things that we look at. The red glowing pupils that you see in flash photos are from the flash reflecting off the retina. When we shine a light through the pupil, a congenital cataract or opacity of the cornea will block the reflected light and show up as a dark area in the red reflex. Distortion of the cornea can cause shadows in the reflex. Using retinoscopy, we can determine the prescription of the eye by moving a streak of light across the pupil and watching how the red reflex changes as hand held lenses are placed in front of the eye.
Since children’s focusing is constantly changing, cycloplegic drops that block their focusing and dilate their pupils allow us to get much more reliable results and a better view of the retina and lens to be sure the eyes are healthy. Getting the drops in is a piece of cake now with an atomizer cap that lets us spritz the drops on each eye. The drop gets in when the child opens their eye. No more prying lids open or trying to get kids to lie back to put a drop in.
So now that you know we can examine infants and young children, what is the best age for a child’s first eye exam? The AOA recommends a first exam between 6 and 12 months of age. Although acuity, eye co-ordination, depth perception and color vision are all very limited at birth, by 6 months visual function should be pretty well developed. If your child hasn’t reached normal vision milestones by 6 months or there is a family history of congenital cataracts or retinoblastoma, there are significant developmental delays or any concerns that something might be wrong with the eyes, I would recommend an exam this early. However, the incidence of significant problems that require intervention at this age is very low and the pediatrician is capable of and should be screening for the most common ones: congenital cataracts, congenital ptosis (lid droop) and significant eye turns, during well baby visits.
It is common for infants to have a high refractive error. In a process called emmetropization, blurred vision triggers growth of the eye to get rid of the blur. To avoid interfering with this natural process, glasses are only prescribed to infants if there is an unusually high refractive error or a major difference between the two eyes that threatens vision development.
In a normal, healthy child with no family history of eye or vision problems, I feel 3 years of age is a good time for the first exam. By age 3, the visual system should be pretty well developed and most children can sit still long enough to get reliable results. Significant refractive errors or eye turns that are present at age 3 need to be treated, or at least monitored, to prevent amblyopia and/or other adaptations that interfere with visual function. Even at this age, we don’t need to precisely pinpoint the exact prescription to assure normal development and prevent amblyopia. We just need to be in the ballpark. As the child matures and can give more reliable responses, the prescription can be fine-tuned.
Children should have another eye exam at age 5 to ensure that are ready for the visual demands of school. If not identified and treated by 5 or 6, strabismus and amblyopia are much more difficult to treat and any loss of visual function is more likely to be permanent.
Regardless of age, you should schedule a comprehensive eye exam for your infant or young child if you notice any of the following signs or symptoms:
· White pupil
· Drooping eyelid that covers part of the pupil
· Doesn’t track and reach for a light or toy by 6 mos.
· One eye always turns in or out
· One eye ever appears to turn in or out after the age of 6 mos.
· Red, watery or crusty eyes or lids
· Rubs eye(s) frequently, even when not tired
· Turns the head to favor one eye, tilts the head to one side or closes one eye
· Regularly holds things very close or sits right in front of the TV
· Avoids doing any detailed activities like puzzles, coloring
· Tends to bump into things or is very clumsy for their age
· Developmental delays
· Any time you feel that something is wrong
There are several things that you can do to optimize the exam experience and results. Be sure to schedule the appointment when the child is well rested and fed. No child is going to be cooperative when they are tired or hungry. Leave other children at home and don’t schedule multiple exams at once. Small children have limited attention spans and there is only a small window when they will cooperate with the exam. Having them sit through other exams or being distracted by siblings is a recipe for trouble.
Most people say vision is their most precious sense and good vision is critical to normal development and success in school. Just as it is important to start regular dental care at a young age, children should receive early and regular eye exams to ensure that they develop and maintain optimal visual function. If your child has never had an eye exam, or it has been more than two years since their last exam, please call our office today at 919-481-4682 or click here to schedule an appointment.