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May 9, 2005

Childhood Myopia: No Clear Choice for Clear Vision
By Kim M. Norton
For The Record

Vol. 17 No. 10 P. 38

The International Myopia Prevention Association has questioned the use of prescription lenses in children. Is it misguided thinking?

There is growing controversy in the ophthalmic community about the correct course of action for treating myopia or nearsightedness when a child presents with blurry vision, headaches, and squinting. Although it is considered the standard of care, some say a prescription for a minus lens may not be the best approach to childhood myopia.

Some experts say myopia is the result of an inherited multigene that predetermines whether a child will be myopic and the severity of the myopia. Opponents of prescription lenses say myopia is not inherited; rather, it is caused by outside factors resulting in the overaccommodation of the ciliary muscles, which renders the child myopic.

Currently, the standard of care for a pediatric myopic patient is to prescribe a minus lens to help the child see more clearly. A minus lens helps focus rays of light further into the myopic eye so a clear image will be displayed on the retina. When a person is myopic, the eyeball is slightly longer than normal, which makes distant objects appear blurry.

Prescription eyeglasses help make distance vision clearer, but only while the lenses are worn. The ophthalmic community is absolute in its position that there is no cure for myopia; however, refractive options are able to correct distance vision. These options include prescription lenses, contact lenses, orthokeratology, and refractive surgery.

Because many parents are now conducting their own Internet-based research and trying to educate themselves about medical conditions, they may find numerous options available for the treatment of their child’s myopia. In addition to refractive surgery and designer frames, there are exercises for strengthening the eye. Other, more controversial methods include pinhole lenses that claim to provide clearer vision and products such as the Myopter, which claims to retard myopia completely.

With so many options available to parents of school-aged children, the age when myopia progresses the fastest, it is easy for parents to become overwhelmed by choices. Donald S. Rehm, scientist, researcher, founder of the International Myopia Prevention Association (IMPA), and author of The Myopia Myth: The Truth About Nearsightedness and How to Prevent It, claims that the ophthalmic community is being dishonest with the general public and doing irreparable harm to young children’s eyes by prescribing minus lenses for myopia.

“There is no reason for any child to need minus prescription lenses for acquired myopia,” Rehm states. According to Rehm, genetics have nothing to do with myopia unless the child is born with the birth defect of congenital myopia, which he says must be treated with minus lenses for the child to overcome the birth defect.

As it appears, there are some discrepancies between the ophthalmic community and the IMPA. Research has demonstrated that if one parent is myopic, there is a 15% chance that the child will be myopic. If both parents are myopic, the chance of inheriting the genetic influence jumps to 60%. According to the National Eye Institute (NEI), 25% of all Americans have myopia.

Rehm, who disagrees with these findings, believes all myopia is induced by eye strain through close reading and work, and can be avoided.

Nature vs. Nurture
“Myopia is determined by a multigene genetic influence that determines a child’s prescription,” says Philip Calenda, MD, PC, FAAO, medical and surgical director of the Westchester Vision Center in Scarsdale, N.Y. “It is certainly not environmental.” Myopia cannot be cured but it can be treated with prescription lenses, he adds.

Geoffrey W. Goodfellow, OD, FAAO, chief of pediatrics at the Illinois Eye Institute in Chicago, represents another point of view. He believes myopia is a combination of both hereditary and environmental factors. “Hereditary genes have a definite impact but at around third or fourth grade, environmental factors become an issue because this is when there is a peak in the child’s prescription. Around the age of 19 to 21 is when the prescription begins to level off,” he says.

With the child’s eye changing throughout adolescence, the prescription is bound to change, Calenda says. Because he believes a child’s myopia is predetermined, prescription lenses are designed to match the prescription of the child’s eye to aid him or her to see clearly. Calenda agrees with the concept that there is no cure for myopia, rather there are ways to improve the situation.

Goodfellow also advises parents to take careful consideration of the eye exam. Often, when a child is examined for suspect myopia, it is the child’s tendency to overfocus, according to Goodfellow. “By overfocusing, the child induces myopia that is not really there and the prescription for nonexistent myopia can perpetuate the decline in the child’s vision,” he says.

To ensure that an accurate assessment of the eye is taken, Goodfellow recommends the dilation of the eye using cycloplegic drops such as Tropicamide 1.0% to paralyze the internal focusing system or accommodation to allow the true prescription to be assessed.

“If no myopia is present, the child may be suffering from overfocusing, which can be corrected with vision therapy or eye coordination exercises,” Goodfellow says. Often, vision therapy can eliminate the problem and the child will see clearly as a result, he adds.

“Any studies showing that [myopia] is environmental have quickly been disproved,” Calenda argues. Although myopia is a genetic condition, he says the best way to treat these patients is to evaluate the child’s eyes to make sure they are fitted with the appropriate prescription lenses that will help them see more clearly.

Can Glasses Worsen the Prognosis?
“Myopia does not worsen with eyeglasses. The eye will reach its predetermined prescription and glasses are designed to meet that number,” Calenda explains. Although other treatments are available for older children, glasses are still the standard of care, he adds.

Goodfellow agrees that prescription eyeglasses are the prevailing treatment but says it is imperative that the appropriate prescription is prescribed or the child’s myopia could worsen rather than stabilize.

In addition to eyeglasses, Goodfellow also advocates the use of contact lenses in children or even infants. “Contact lenses can help normal vision develop in infants that have severe vision problems,” he says. Contact lenses should be viewed as a medical device in these patients, Goodfellow adds.

The IMPA and Rehm are in direct disagreement with Calenda and Goodfellow.

In his book and on his Web site, Rehm states that prescription lenses worsen the child’s eye. In his opinion, store-bought reading glasses (up to +3 D) would be a better option because the reading glasses would “eliminate accommodation at a normal reading distance.”

Calenda argues this notion, stating, “Reading glasses are prescription glasses, saying otherwise is unfounded.”

The pediatric myopic patient already has too much plus power in his or her eye and adding more will only make his or her vision more blurry.

“Plus lenses will not correct or eliminate myopia, but if they are used in the long term they could damage the young eye beyond repair,” Calenda says. “If used for a great length of time, reading glasses could instigate amblyopia, which left undetected until the age of 12, the child could suffer permanent damage to the eye.”

Rehm disagrees. He believes that if a child uses reading glasses and holds the reading material at a distance of 15 inches, the child will see clearly. “The material should be just blurry but still clear,” he says.

The biggest concern Rehm has with the ophthalmic community is the lack of direction given to children who are prescribed minus lenses. “The eye doctors do not tell them to take off their glasses for close work, they just fit them with lenses and send them out,” he explains.

“The public deserves the truth,” Rehm continues. “Eye doctors would better serve the public if they did not waste people’s money by giving children glasses they do not need. Instead, these doctors should go into the schools and provide eye exams there, which would defray the loss of revenue from prescribing unnecessary glasses.”

According to the Correction of Myopia Evaluation Trial, conducted by the NEI from September 1998 to September 1999, progressive addition lenses (reading glasses) slowed the progression of myopia in the study group when compared with single vision lenses within the first year of the trial.

Although there was some difference between the two groups, the NEI states that “the small magnitude of effect does not warrant a change in clinical practice.”

Reading glasses will make the myopic child’s vision blurrier and these glasses “will prevent normal development of the eye,” Calenda says.

Rehm and the IMPA submitted a petition to the FDA in March requiring that eye doctors issue written warnings to the parents of pediatric myopic patients. The warning would advise parents that distance lenses worsen myopia in children and that the prescribing of reading glasses for excessive close work may reduce or prevent myopia.

Other Treatment Options
Besides prescription lenses, there are alternatives for older children who choose not to wear their glasses or cannot wear them. Contact lenses are one solution for older children and LASIK or refractive surgery may be another option, Calenda says.

However, LASIK should be considered a last resort in vision correction, according to both Calenda and Goodfellow. The eye is continuing to change and altering the surface of the cornea with ablation is not always the best course of action. Although not a first-line treatment, surgeons have seen good outcomes with LASIK in this patient population, Calenda says.

Another alternative to contact lenses are the Paragon CRT (Corneal Refractive Therapy) contact lenses. The Paragon lenses are intended for children over the age of 10 who are active during the day and believe their glasses inhibit their regular activities.

The Paragon lenses work by temporarily reshaping the cornea while the child sleeps. “The lenses significantly improve vision during the day, but if the child does not wear the lenses overnight, the effect will cease. So these are not a cure,” Calenda explains. The lenses can be used in prescriptions up to -6 D and with astigmatism up to 1.5 D.

Goodfellow also recommends orthokeratology, or the use of rigid contact lenses at night in children as well as adults who would like freedom from their glasses during the day. However, Goodfellow explains that children are more likely to see better results than adults with orthokeratology.

Other Products
Various Web sites also discuss pinhole glasses as an option for myopia correction. Pinhole glasses are designed to focus light rays directly onto the retina without being bent. While the person is wearing these lenses, he or she will have clearer vision but there will be no peripheral vision because of the design of the glasses.

The lenses reduce the blur associated with myopia by distorting the light coming into the eye. Pinhole glasses also reduce the amount of accommodation the eye must use so the person can see much more clearly.

However, the glasses are not designed for persons with myopia greater than -6 D, according to the IMPA. The IMPA advises that stronger efforts be undertaken in these cases, although no specific measures are stated.

“Pinhole lenses can damage the peripheral vision of the child and if used excessively can stop the child’s eye from developing normally,” Calenda explains. Although the child may see an improvement to 20/30 or 20/25, the peripheral vision can be damaged by promoting more rays of light to project directly onto the retina rather than the small percentage that do naturally, he adds.

According to a March 16, 1994, press release from the Federal Trade Commission, “The use of pinhole glasses does not result in long-term improvement in nearsightedness, farsightedness, or astigmatism.” Additionally, it was stated that pinhole glasses do not cure, correct, or improve any of these ailments. Furthermore, “pinhole glasses are not a replacement for prescription lenses and there is no scientific research to back up the claims made by persons or organizations selling these glasses as a replacement for prescription lenses.”

Another product available exclusively from the IMPA is the Myopter. The Myopter, patented in 1972, works by the same principle as reading glasses but with the use of binocular lenses, according to the Web site. The Myopter is better for close reading and work than reading glasses, the IMPA states.

Ideally, the child should use pinhole glasses during the day and the Myopter at home to eliminate myopia entirely, according to the IMPA. “No child ever needs minus lenses,” Rehm says.

The Myopter is only available through the IMPA Web site because, according to Rehm, “the optometric society doesn’t want to touch this. I cannot find any distributors for it because the eye doctors want the Myopter to be suppressed.”

The FDA has not approved either pinhole lenses or the Myopter. “These items were put on the market before the FDA began regulating medical devices,” Rehm explains.

Future Treatment Options
Another treatment option that may be on the horizon for pediatric myopic patients is the ophthalmic gel Pirenzepine 2%.

In a recent one-year, double-masked, placebo-controlled parallel study of patients aged 8 to 12, the researchers found that Pirenzepine is an effective and relatively safe treatment plan for slowing the progression of myopia.

Pirenzepine retards the progression of myopia by reducing the development of deprivation-induced myopia and axial elongation, according to animal studies.

Goodfellow says that although pharmacological items are not yet the standard of care for treating myopia, they have the potential to be a good treatment modality once proven safe and effective.

— Kim M. Norton is a freelance writer/journalist.

Resources

Correction of Myopia Evaluation Trial. Conducted by the NEI: September 1998 to September 1999.

Federal Trade Commission
www.ftc.gov

International Myopia Prevention Association
www.myopia.org

National Eye Institute
www.nei.nih.gov

Siatkowski RM, Cotter S, Miller JM, et al for the US Pirenzepine Study Group. Arch Ophthal. 2004;122:1667-1674.

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