HOW TO PRESCRIBE KIDS’ GLASSES

Glasses prescriptions do not represent an immutable, objective number. We do not measure your eye and generate a number that is immutable and definite — if we did that, you would not feel as satisfied as you do today. Taking a measurement of the eye is just one component of a successful glasses prescription, since the visual system involves more than just the eye itself and the muscles around it as well as the visual cortex of the brain.  In prescribing drugs to children, doctors are at a significant disadvantage due to the subjective responses of the patients being unreliable. There are kids who are shy, some who are scared, and some who truly, truly, really, really want glasses. Parents might be concerned that something must be horribly wrong because their child cannot see the big E! That is one of the most challenging situations.  You are surprised to learn that the doctor tells you that your child does not require glasses, and then you cry in disappointment as your child wails. Today, we will discuss the art of prescribing for kids — when to prescribe, what to prescribe, and how to get children to wear glasses.

Don’t go below zero

Many parents are concerned that the prescriptions of their children are changing too rapidly, and they may even ask their doctor to decrease the prescription so that it is not “too strong.” Nevertheless, a prescription that is underminused in school-age children (made weaker by intention) has a negative impact on the eye’s development compared to one that corrects vision clearly. In 2002, a study concluded that the eyes of nearsighted children deteriorated faster when their prescriptions were under corrected by +0.75D, compared to those who were prescribed their full strength prescription. It is argued that children with blurred vision change at a faster rate due to the presence of any blurred vision. The best approach for nearsighted (myopic) school-age children is to prescribe the full amount to achieve 20/20 vision. The parents should be reminded to schedule a follow-up appointment if their child complains of changing vision in the next six months.  Rather than letting them continue to have blurry vision for another six months with the risk of accelerated myopia progression, it is better to adjust their glasses mid-year to achieve clarity. For additional information on myopia control, please review the following article.

Be careful not to overextend yourself

Especially in young children, hyperopia (farsightedness) is a normal occurrence. The average newborn has approximately 2.00 diopters of hyperopia, while the average 2 year old has approximately 1.00 diopters. There is a broad range of acceptable variability within which a child can still expect to maintain normal vision. When should the prescription be made?

If the prescription is greater than 3.50 D, prescribe if the prescription is smaller than 1.50 D

Prescribe if Rx is over +2.50 D and cut Rx to 1.00 D for 4-5 year olds

When the Rx over +1.50 D or if the patient is symptomatic, prescribe; no reduction in the Rx is necessary.

As a result of decreasing the prescription in young hyperopic patients, the patient’s eyes may normalize to zero as they continue to grow (called emmetropization). You do not need to reduce the prescription by age 6 because emmetropization is almost over by that time.  Most school-aged children are likely to do well without glasses, even if they have low hyperopic prescriptions, as long as they have good vision acuity, normal binocular and accommodative function, and no complaints.

Astigmatism correction

Many infants are born with astigmatism of over one.00D. It is estimated that 69% of infants have astigmatism. Children who are born with astigmatism usually begin to improve rapidly by the age of four, so prescribing astigmatism in young children is usually not necessary. However, if astigmatism persists by the time they are in school, it can have a significant impact on their performance in the classroom.  There has been a study published in 2016 that revealed that correcting the prescription of children who have high amounts of astigmatism (3.00D or more) has a direct effect on their reading fluency, resulting in an average grade level improvement.

When should a prescription be written?

For patients under the age of 2 with astigmatism exceeding 2.50 D, reduce the prescription by 50% for the cylinder

If the patient has an astigmatism greater than 2.00 D, prescribe a 50 percent reduction in cylinder prescription for 2-4-year-olds

Those aged 5 and up should be prescribed if astigmatism exceeds 1.50 D or if they are symptomatic with less astigmatism. There is no need to adjust the prescription

There is the possibility that astigmatism may make it difficult to distinguish between letters and numbers, especially in higher grades when the font size becomes smaller.

This rule is exceptionable when there are significant differences in prescription between the eyes (called anisometropia) and amblyopia (lazy eye) or strabismus (eye turn) are developing. In order to achieve the best possible outcome, it becomes important to prescribe the full amount of prescription to very young children.

Accommodative Dysfunction should be considered

In many cases, a child without a prescription who fails to read the chart is considered malingering (a polite term for faking it). These days, glasses are the coolest thing to have, and sometimes when a child’s friend gets glasses, your child becomes determined to acquire glasses as well. Occasionally, a child may not have a physical problem with distance vision, but will be unable to read the chart due to a genuine medical condition.  To rule out accommodative dysfunction, I always perform an easy and quick accommodative test (NRA/PRA works best for responsive children, MEM Retinoscopy for younger children). As a result of their focusing system being “locked up” at near, children who have accommodative dysfunction cannot see clearly in the distance. As a result, their eyes will be unable to adjust between distance and up close, which will result in blurry images of distances.  Children with this issue may benefit from referrals to vision therapy, and progressive glasses may be able to aid them in adjusting from near to far more easily.

Myopes: when to prescribe progressives? It was widely believed that progressive lenses could reduce the speed at which nearsighted children’s vision worsened over the course of the year. According to the COMET study, prescribing progressive or bifocal glasses for the control of nearsightedness did not improve the eyesight of children with normal focusing systems. A normal nearsighted child prescribed progressive glasses did not slow down the development of myopia. When progressive glasses are prescribed for the right patient, progressive glasses can be beneficial for myopic children with accommodative dysfunction.

Safety and sun protection should not be overlooked

Children are at the highest risk of developing ocular sun damage. In fact, 25% of sun damage occurs before the age of 18. Sun damage to the eye can result in potentially fatal diseases like ocular melanoma, as well as eye conditions associated with aging, such as cataracts and macular degeneration. These conditions are not caused by sun damage we accumulate when we are 80 years old; they result from sun damage we acquired in childhood.  This is the reason why it is crucial to prescribe sun protection in children’s glasses. Transition lenses are able to provide 100% UVA and UVB protection without requiring kids to manage multiple pairs of glasses.

The sporty appearance of rec specs has been a huge trend in youth eyewear over the last few years. For many kids, wearing rec specs makes them feel more confident than wearing traditional metal round frames.

It is also important to remember that injuries are another major risk for children’s eyesight, especially if they play sports. 90% of the blinding sports-related eye injuries could have been prevented if the child had worn protective eyewear. Children’s glasses must be equipped with shatter-resistant lenses, such as polycarbonate or trivex, to prevent eye injury both on and off the field.

Do not underestimate how a child’s self esteem can be influenced by their perceived appearance. Parents should always allow their children to participate in the selection process when the child enters school. In addition to increasing the likelihood that their glasses will be worn, higher self esteem correlates with higher academic performance as well. Their glasses need to be an integral part of their identity that they enjoy.