Orthokeratology & Myopia Control
Dr. Horak is a member of the American Academy of Orthokeratology & Myopia Control. He is certified to fit special, high oxygen permeable contact lenses to reduce the deterioration of your child’s eyesight. This procedure is called orthokeratology, or “ortho-k” for short. Ortho k is also referred to as:
Gentle Vision Shaping System (GVSS)
Vision Shaping Treatment by Bausch and Lomb (VST)
Corneal Refractive Therapy by Paragon (CRT)
Overnight Vision Correction
Studies show that ortho-k decreases the deterioration of a child’s eyesight on average by 50%. With this technique, the deterioration of you child’s eyesight will not only slow down, which should decrease the chances of serious eye disease, but it will also allow your child to see clear and comfortable throughout the day WITHOUT GLASSES or day-time contacts.
Not everyone is a candidate for orthokeratology, so Dr. Horak recommends a consultation to determine if your child is a good candidate for this life changing, non-surgical procedure.
In fact, a recent study by the National Eye Institute (NEI) shows the prevalence of myopia grew from 25 percent of the U.S. population (ages 12 to 54) in 1971-1972 to a whopping 41.6 percent in 1999-2004.
Though the exact cause for this increase in nearsightedness among Americans is unknown, many eye doctors feel it has something to do with eye fatigue from computer use and other extended near vision tasks, coupled with a genetic predisposition for myopia.
Myopia Symptoms and Signs
If you are nearsighted, you typically will have difficulty reading road signs and seeing distant objects clearly, but will be able to see well for close-up tasks such as reading and computer use.
If you experience these signs or symptoms while wearing your glasses or contact lenses, schedule acomprehensive eye examination with your optometrist or ophthalmologist to see if you need a stronger prescription.
What Causes Myopia?
Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface.
Myopia typically begins in childhood and you may have a higher risk if your parents are nearsighted. In most cases, nearsightedness stabilizes in early adulthood but sometimes it continues to progress with age.
Nearsightedness can be corrected with glasses, contact lenses or refractive surgery. Depending on the degree of your myopia, you may need to wear your glasses or contact lenses all the time or only when you need very clear distance vision, like when driving, seeing a chalkboard or watching a movie.
If you’re nearsighted, the first number (“sphere”) on your eyeglasses prescription or contact lens prescription will be preceded by a minus sign (–). The higher the number, the more nearsighted you are.
Refractive surgery can reduce or even eliminate your need for glasses or contacts. The most common procedures are performed with an excimer laser.
- In PRK the laser removes a layer of corneal tissue, which flattens the cornea and allows light rays to focus more accurately on the retina.
- In LASIK — the most common refractive procedure — a thin flap is created on the surface of the cornea, a laser removes some corneal tissue, and then the flap is returned to its original position.
Then there’s orthokeratology, a non-surgical procedure where you wear special rigid gas permeable (RGP or GP) contact lenses at night that reshape your cornea while you sleep. When you remove the lenses in the morning, your cornea temporarily retains the new shape, so you can see clearly during the day without glasses or contact lenses.
Orthokeratology and a related GP contact lens procedure called corneal refractive therapy (CRT) have been proven effective at temporarily correcting mild to moderate amounts of myopia. Both procedures are good alternatives to surgery for individuals who are too young for LASIK or are not good candidates for refractive surgery for other reasons.
Implantable lenses known as phakic IOLs are another surgical option for correcting nearsightedness, particularly for individuals with high amounts of myopia or thinner-than-normal corneas that could increase their risk of complications from LASIK or other laser vision correction procedures.
Phakic IOLs work like contact lenses, except they are surgically placed within the eye and typically are permanent, which means no maintenance is needed. Unlike IOLs used in cataract surgery, phakic IOLs do not replace the eye’s natural lens, which is left intact.
With more and more people getting nearsighted these days, there is a lot of interest in finding ways to control the progression of myopia in childhood.
Recently, researchers in New Zealand have reported encouraging outcomes from specially designed “dual focus” soft contact lenses for myopia control in nearsighted children. The experimental lenses have significantly less power in the periphery of the lens compared to the center, and it is thought that this “peripheral defocus” may reduce the tendency for greater lengthening of the eye that leads to progressive myopia.
In a study published in 2011, the researchers found that in 70 percent of nearsighted children (ages 11 to 14) who wore the experimental lenses in one eye and a standard soft contact lens in the other, myopia progression was reduced by 30 percent or more in the eye wearing the dual focus contact lens.
Though dual focus contact lenses for myopia control are not yet available in the United States, research is ongoing to evaluate the effectiveness of the lenses on a larger population of children.
In most cases, nearsightedness is simply a minor inconvenience and poses little or no risk to the health of the eye. But sometimes myopia can be so progressive and severe it is considered a degenerative condition.
Degenerative myopia (also called malignant or pathological myopia) is a relatively rare condition that is believed to be hereditary and usually begins in early childhood. About 2 percent of Americans are afflicted, and degenerative myopia is a leading cause of legal blindness.
In malignant myopia, the elongation of the eyeball can occur rapidly, leading to a quick and severe progression of myopia and loss of vision. People with the condition have a significantly increased risk of retinal detachment and other degenerative changes in the back of the eye, including bleeding in the eye from abnormal blood vessel growth (neovascularization).
Degenerative myopia also may increase the risk of cataracts.
Surgical treatment for complications of degenerative myopia includes a combination drug and laser procedure called photodynamic therapy that also is used for the treatment of macular degeneration.
Also, a recent pilot study found that an oral medicine called 7-methylxanthine (7-mx) was effective in slowing the elongation of the eye in nearsighted children ages 8 to 13. Studies of this type might eventually lead to an effective medical treatment for degenerative myopia.
Myopia Causes - Is Your Child at Risk?
Parents — especially those who are nearsighted and had to wear glasses throughout childhood — are often concerned about the causes of myopia and whether their children are doomed to being nearsighted, too.
If this sounds like you, try not to worry too much.
Myopia is a common refractive error, it’s easily treatable with contact lenses as well as eyeglasses, and it’s not strictly hereditary.
Also, nearsightedness typically does not affect a child’s academic performance or hold them back in any way. In fact, there’s evidence that nearsighted children tend to perform better in school than their counterparts with normal eyesight, farsightedness or astigmatism.
What Causes Myopia in Children?
Although the exact reason why some children become nearsighted and others do not is not fully understood, it appears heredity is a factor, but not the only one.
In other words, if both parents are nearsighted, there is a greater risk their children will be nearsighted, too. But you can’t predict who will become nearsighted by simply looking at their family tree.
In my case, my parents and both my older brothers had perfect vision. I’m the only one in the family who is nearsighted. Go figure.
I loved to read when I was a kid (still do); my brothers, not so much. Some researchers think focusing fatigue from excessive reading or holding a book too close to your eyes for extended periods can increase the risk for myopia in children. But nobody knows for sure.
The cause (or causes) of myopia may remain a mystery, but researchers recently have discovered something about the progression of nearsightedness that is very interesting: conventional glasses and contact lenses that have been prescribed for years to correct myopia may actually increase the risk of myopia worsening throughout childhood!
Many of these same researchers are investigating new lens designs to see if they can develop contact lenses or eyeglasses that can control myopia and halt or slow the progression of nearsightedness in children.
How to Reduce Your Child’s Risk of Myopia
This might sound glib, but perhaps one of the best things to tell your child to reduce his or her risk of myopia is, “Go outside and play!”
A number of recent studies have found that spending more time outdoors may help prevent or reduce the progression of nearsightedness in children. Among them:
- In August 2008, researchers in Australia published the results of the large Sydney Myopia Study of the effect of time spent outdoors on the development and progression of myopia among 1,765 6-year-olds and 2,367 12-year-olds randomly selected from 51 Sydney schools.The 12-year-old children who spent more time outdoors had less myopia at the end of the two-year study period than others in the study — even after adjusting for the amount of reading performed, parental myopia and ethnicity.
Children who performed the most amount of near work and spent the least amount of time outdoors had the highest mean amount of nearsightedness.
- In May 2013, researchers in Taiwan published the results of a study of the effect of outdoor activity during class recess on myopia risk and progression among elementary school students.Children participating in the one-year study ranged from 7 to 11 years of age and were recruited from two nearby schools located in a suburban area of southern Taiwan.
A total of 333 children from one school were encouraged to go outside for outdoor activities during recess, whereas 238 children from the other school did not participate in a special “recess outside the classroom” (ROC) program.
At the beginning of the study, there were no significant differences between the two groups of children with regard to age, gender, and myopia prevalence (48 percent vs. 49 percent). But after one year, the children from the school that spent time outside during recess had a significantly lower onset of new myopia than the children from the school that did not encourage outside activity during recess (8.4 percent vs. 17.6 percent).
There also was significantly lower average progression of myopia among already nearsighted children in the ROC group compared with the group that spent more recess time indoors (-0.25 diopter [D] per year vs. -0.38 D per year).
The study authors concluded that outdoor activities during recess in elementary school have a significant protective effect on myopia risk among children that are not yet nearsighted and reduce the progression of myopia among nearsighted schoolchildren.
- Also in May 2013, researchers in Denmark published a study of the seasonal effect of available daylight on myopia development among Danish schoolchildren.Myopia risk was determined by measurement of the axial (front-to-back) elongation of the children’s eyes in different seasons. Increasing axial length of the eye is associated with increasing nearsightedness.
The amount of daylight changes significantly with the seasons in Denmark, ranging from nearly 18 hours per day in summertime to only seven hours per day in winter months.
In winter (when the children had access to the fewest hours of daylight), average growth in the axial length of their eyes was significantly greater than it was in summer, when their outdoor sunlight exposure was greatest (0.19 mm vs. 0.12 mm).
- And at the 2011 annual meeting of the American Academy of Ophthalmology, researchers from the UK presented a meta-analysis of pooled data from eight well-designed studies of the effect of time spent outdoors on the development and progression of myopia among 10,400 children and adolescents.The researchers calculated a 2 percent drop in the risk of developing myopia for each additional hour children spend outdoors per week. “This is equivalent to an 18 percent reduction for every additional hour of exposure per day,” they said.
Compared with children with normal eyesight or farsightedness, children with myopia spent an average of 3.7 fewer hours per week outside, they added. No particular outdoor activity was linked to the reduced chance of myopia — it was just the state of being outdoors rather than indoors. Also no correlation was found between myopia occurrence and a tendency to do more near work such as studying.
The researchers said more study is needed to determine which outdoor-related factors are most important, such as more distance vision use, less near vision use, physical activity and exposure to natural ultraviolet light.
Given the research above, it’s a great idea to encourage your children to spend more time outdoors (and leave the cell phone and other electronic devices at home or in their pockets!).
Doing so just might decrease their risk of becoming nearsighted — or slow the progression of their current level of myopia.
Better yet, join them for some quality time outdoors together!
Why Myopia Progression Is a Concern
Are your child’s eyes getting worse year after year?
Some children who develop myopia (nearsightedness) have a continual progression of their myopia throughout the school years, including high school. And while the cost of annual eye exams and new glasses every year can be a financial strain for some families, the long-term risks associated with myopia progression can be even greater.
More Children Are Becoming Nearsighted
Myopia is one of the most common eye disorders in the world. The prevalence of myopia is about 30 to 40 percent among adults in Europe and the United States, and up to 80 percent or higher in the Asian population, especially in China.
And the incidence and prevalence of myopia are increasing. For example, in the early 1970s, only about 25 percent of Americans were nearsighted. But by 2004, myopia prevalence in the United States had grown to nearly 42 percent of the population.
Classification of Myopia Severity
Myopia — like all refractive errors — is measured in diopters (D), which are the same units used to measure the optical power of eyeglasses and contact lenses.
Lens powers that correct myopia are preceded by a minus sign (–), and are usually measured in 0.25 D increments.
The severity of nearsightedness is often categorized like this:
- Mild myopia: -0.25 to -3.00 D
- Moderate myopia: -3.25 to -6.00 D
- High myopia: greater than -6.00 D
Mild myopia typically does not increase a person’s risk for eye health problems. But moderate and high myopia sometimes are associated with serious, vision-threatening side effects. When this occurs in cases of high or very high myopia, the term degenerative myopia or pathological myopia sometimes is used.
Adults with high myopia usually started getting nearsighted when they were young children, and their myopia progressed year after year.
Myopia-Related Eye Problems
Here is a brief summary of significant eye problems that sometimes are associated with nearsightedness, particularly high myopia:
Myopia and cataracts. In a recent study of cataracts and cataract surgery outcomes among Koreans with high myopia, researchers found cataracts tended to develop sooner in highly myopic eyes compared with normal eyes.
And eyes with high myopia had a higher prevalence of coexisting disease and complications, such as retinal detachment.
Also, visual outcomes following cataract surgery were not as good among highly nearsighted eyes.
In an Australian study of more than 3,600 adults ages 49 to 97, the odds of having cataracts increased significantly with greater amounts of myopia.
Plus, the odds of having a particular type of cataract was twice as high among subjects with high myopia compared with those with low myopia.
Myopia and glaucoma. Myopia — even mild and moderate myopia — has been associated with an increased prevalence of glaucoma. In the same Australian study mentioned above, glaucoma was found in 4.2 percent of eyes with mild myopia and 4.4 percent of eyes with moderate-to-high myopia, compared with 1.5 percent of eyes without myopia.
The study authors concluded there is a strong relationship between myopia and glaucoma, and that nearsighted participants in the study had a two to three times greater risk of glaucoma than participants with no myopia.
Also, in a Chinese study, glaucoma was significantly associated with the severity of myopia. Among adults age 40 or older, those with high myopia had more than twice the odds of having glaucoma as study participants with moderate myopia, and more than three times the odds of having the disease compared with individuals with mild myopia.
Compared with participants who either had no myopia or were farsighted, those with high myopia had a 4.2 to 7.6 times greater odds of having glaucoma.
Myopia and retinal detachment. In a study published inAmerican Journal of Epidemiology, researchers found myopia was a clear risk factor for retinal detachment.
Results showed eyes with mild myopia had a four-fold increased risk of retinal detachment compared with non-myopic eyes. Among eyes with moderate and high myopia, the risk increased 10-fold.
The study authors also concluded that almost 55 percent of retinal detachments not caused by trauma are attributable to myopia.
In the Korean study mentioned above, among participants with high myopia due to elongated eye shape (axial myopia), the incidence of retinal detachment after cataract surgery was 1.72 percent, compared with 0.28 percent among participants with normal eye shape.
In a study conducted in the UK of the incidence of retinal detachment after cataract surgery, 2.4 percent of highly myopic eyes developed a detached retina within seven years following cataract extraction, compared with an incidence of 0.5 to 1 percent among eyes of any refractive error that underwent cataract surgery.
Myopia and refractive surgery. Also, many people with high myopia are not well-suited for LASIK or other laser refractive surgery. (Highly myopic individuals may still be good candidates for phakic IOL implantation or other vision correction procedures, however.)
What You Can Do About Myopia Progression
The best thing you can do to help slow the progression of your child’s myopia is to schedule annual eye exams so your eye doctor can monitor how much and how fast his or her eyes are changing.
Often, children with myopia don’t complain about their vision, so be sure to schedule annual exams even if they say their vision seems fine.
Myopia Control - A Cure for Nearsightedness?
If your child has myopia (nearsightedness), you’re probably wondering if there is a cure — or at least something that can be done to slow its progression so your child doesn’t need stronger glasses year after year.
For years, eye care practitioners and researchers have been wondering the same thing. And there’s good news: A number of recent studies suggest it may indeed be possible to at least control myopia by slowing its progression during childhood and among teenagers.
What Is Myopia Control?
Although an outright cure for nearsightedness has not been discovered, your eye doctor can now offer a number of treatments that may be able to slow the progression of myopia.
These treatments can induce changes in the structure and focusing of the eye to reduce stress and fatigue associated with the development and progression of nearsightedness.
Why should you be interested in myopia control? Because slowing the progression of myopia may keep your child from developing high levels of nearsightedness that require thick, corrective eyeglasses and have been associated with serious eye problems later in life, such as early cataracts or even a detached retina.
Currently, four types of treatment are showing promise for controlling myopia:
- Atropine eye drops
- Multifocal contact lenses
- Orthokeratology (“ortho-k”)
- Multifocal eyeglasses
Here’s a summary of each of these treatments and of recent myopia control research:
Atropine Eye Drops
Atropine eye drops have been used for myopia control for many years, with effective short-term results. But use of these eye drops also has some drawbacks.
Topical atropine is a medicine used to dilate the pupil and temporarily paralyze accommodationand completely relax the eyes’ focusing mechanism.
Atropine typically is not used for routine dilated eye exams because its actions are long-lasting and can take a week or longer to wear off. (The dilating drops your eye doctor uses during your eye examtypically wear off within a couple hours.)
A common use for atropine these days is to reduce eye pain associated with certain types of uveitis.
Because research has suggested nearsightedness in children may be linked to focusing fatigue, investigators have looked into using atropine to disable the eye’s focusing mechanism to control myopia.
And results of studies of atropine eye drops to control myopia progression have been impressive — at least for the first year of treatment. Four short-term studies published between 1989 and 2010 found atropine produced an average reduction of myopia progression of 81 percent among nearsighted children.
However, additional research has shown that the myopia control effect from atropine does not continue after the first year of treatment, and that short-term use of atropine may not control nearsightedness significantly in the long run.
Interestingly, one study found that when atropine drops were discontinued after two years of use for myopia control, children who were using drops with the lowest concentration of atropine (0.01 percent) had more sustained control of their nearsightedness than children who were treated with stronger atropine drops (0.1 percent or 0.5 percent). They also had less “rebound” myopia progression one year after treatment.
Also, many eye doctors are reluctant to prescribe atropine for children because long-term effects of sustained use of the medication are unknown.
Other drawbacks of atropine treatment include discomfort and light sensitivity from prolonged pupil dilation, blurred near vision, and the added expense of the child needing bifocals or progressive eyeglass lenses during treatment to be able to read clearly, since his or her near focusing ability is affected.
Orthokeratology is the use of specially designed gas permeable contact lenses that are worn during sleep at night to temporarily correct nearsightedness and other vision problems so glasses and contact lenses aren’t needed during waking hours.
But some eye doctors use “ortho-k” lenses to also control myopia progression in children. Evidence suggests nearsighted kids who undergo several years of orthokeratology may end up with less myopia as adults, compared with children who wear eyeglasses or regular contact lenses during the peak years for myopia progression.
Many eye care practitioners refer to these lenses as “corneal reshaping lenses” or “corneal refractive therapy (CRT)” lenses rather than ortho-k lenses, though the lens designs may be similar.
In 2011, researchers from Japan presented a study that evaluated the effect of ortho-k lenses on eyeball elongation in children, which is a factor associated with myopia progression.
A total of 92 nearsighted children completed the two-year study: 42 wore overnight ortho-k lenses and 50 wore conventional eyeglasses during the day. The average age of children participating in the research was about 12 years at the beginning of the study, and children in both groups had essentially the same amount of pre-existing myopia (-2.57 D) and the same axial (front-to-back) eyeball length (24.7 mm).
At the end of the study, children in the eyeglasses group had a significantly greater increase in the mean axial length of their eyes than children who wore the ortho-k contact lenses. The study authors concluded that overnight orthokeratology suppressed elongation of the eyes of children in this study, suggesting ortho-k might slow the progression of myopia, compared with wearing eyeglasses.
In 2012, the same researchers published the results of a similar five-year study of 43 nearsighted children that showed wearing ortho-k contact lenses overnight suppressed axial elongation of the eye, compared with wearing conventional eyeglasses for myopia correction.
Also in 2012, researchers in Spain published study data that revealed children 6 to 12 years of age with -0.75 to -4.00 D of myopia who wore ortho-k contact lenses for two years had less myopia progression and reduced axial elongation of their eyes than similar children who wore eyeglasses for myopia correction.
In October 2012, researchers in Hong Kongpublished yet another study of the effect of ortho-k contact lenses on controlling myopia progression in children. A total of 78 nearsighted children ages 6 to 10 years at the onset of the investigation completed the two-year study.
Children who wore ortho-k lenses had a slower increase in axial length of their eyes by 43 percent, compared with kids who wore eyeglasses. Also, the younger children fitted with the corneal reshaping GP lenses had a greater reduction of myopia progression than the older children.
Furthermore, as myopia control expert Jeffrey J. Walline, OD, PhD, from The Ohio State University College of Optometry pointed out in his analysis of the study published in the same issue of Investigative Ophthalmology & Visual Science, the benefit of slowed myopia progression from wearing the corneal reshaping lenses extended beyond the first year of myopia treatment.
In March 2014, researchers in Taiwan published results of a study that compared the use of ortho-k contact lenses vs. atropine eye drops for the control of myopia in children ages 7 to 17. Participants had myopia ranging from -1.50 to -7.50 D (with up to -2.75 D of astigmatism) at the beginning of the three-year study period.
The two myopia control treatments produced comparable results: children wearing the ortho-k lenses experienced myopia progression of -0.28 D per year, and those who wore eyeglasses and applied 0.125 percent atropine eye drops nightly had an average myopia progression of -0.34 D per year.
Although this study did not include a control group that received no treatment to control myopia, the study authors mentioned that in similar studies the progression of nearsightedness among children wearing ortho-k lenses for myopia control was roughly half that of those who received no myopia control treatment over a two-year period.
Multifocal Contact Lenses
Multifocal contacts are special lenses that have different powers in different zones of the lens to correct presbyopia as well as nearsightedness or farsightedness (with or without astigmatism).
But researchers and eye doctors are finding that conventional or modified multifocal soft contact lenses also are effective tools for myopia control.
In 2010, researchers from Australia, China and the United States presented data from a study of experimental myopia control contact lenses worn by Chinese schoolchildren for six months. The contacts had a special dual-focus multifocal design with full corrective power in the center of the lens and less power in the periphery.
Participants were between the ages of 7 and 14 at the onset and had -0.75 to -3.50 diopters (D) of myopia, with no more than 0.50 D of astigmatism. A total of 65 children wore the experimental multifocal contacts, and 50 children wore eyeglasses. After six months, the children wearing the multifocal contact lenses had 54 percent less progression of their myopia than the children wearing eyeglasses.
In June 2011, researchers in New Zealand reported on a comparison of an experimental multifocal soft contact lens and conventional soft lenses for myopia control in children. A total of 40 nearsighted children ages 11 to 14 participated in the study. The children wore the multifocal contact lens on one randomly assigned eye and a conventional soft contact lens on the fellow eye for 10 months, then switched the lenses to the opposite eye for another 10 months.
In 70 percent of the children, myopia progression was reduced by 30 percent or more in the eye wearing the experimental multifocal contact lens in both 10-month periods of the study.
In November 2013, researchers in the U.S. published the results of a two-year study that revealed nearsighted children who wore multifocal soft contact lenses on a daily basis had 50 percent less progression of their myopia, compared with similarly nearsighted children who wore regular soft contact lenses for two years.
Children participating in the study ranged in age from 8 to 11 years and had -1.00 to -6.00 D of myopia at the time of enrollment.
The study authors concluded that the results of this and previous myopia control studies indicate a need for a long-term, randomized clinical trial to further investigate the potential of multifocal soft contact lenses to control the progression of nearsightedness in children and thereby reduce risks associated with high myopia.
Nearly Half Of The Global Population May Be Nearsighted By 2050, Researchers Say
February 2016 — Researchers at the Brien Holden Vision Institute in Sydney, Australia, recently pored over data from 145 studies and analyzed the prevalence of myopia and high myopia among 2.1 million study participants. The group also used data published since 1995 to estimate trends from 2000 to 2050.
What they found was alarming.
An estimated 1.4 billion people worldwide were nearsighted in 2000. That’s about 23 percent of the total global population. But by 2050, the researchers predict this figure will soar to 4.8 billion, afflicting 49.8 percent of the world’s population.
The good news is, there are ways to protect your children from landing on the wrong side of this statistic. One key may be to encourage them to turn off their electronic devices and head outdoors.
The study points out that the projected increases in myopia are driven principally by lifestyle changes characterized by more near-work activities, like using computers and portable electronic devices, including smartphones. Other proposed risk factors for myopia include long hours spent in the classroom and less time outdoors, especially among young children in countries such as Singapore, Korea, Taiwan and China.
Although the vision of most people with nearsightedness can be corrected with glasses and contact lenses, high levels of myopia increase the risk of eye diseases such as cataracts, glaucoma, retinal detachment and myopic macular degeneration — all of which can cause irreversible vision loss.
The study report authors concluded that the prevalence of high myopia is likely to increase seven-fold from 2000 to 2050, which would make myopia a leading cause of permanent blindness worldwide. The report appeared online this month on the website of the journal Ophthalmology. — A.H.
Multifocal eyeglasses also have been tested for myopia control in children, but results have been less impressive than those produced with multifocal contacts.
A number of studies published between 2000 and 2011 found that wearing multifocal eyeglasses does not provide a significant reduction in progressive myopia for most children.
The Correction of Myopia Evaluation Trial (COMET), a study published in 2003, found that progressive eyeglass lenses, compared with regular single vision lenses, did slow myopia progression in children by a small but statistically significant amount during the first year. But the effect wasn’t significant in the next two years of the study.
But in March 2014, researchers in Australia and China published the results of a three-year clinical trial that evaluated the progression of nearsightedness among 128 myopic children ages 8 to 13 years. All participants had experienced at least -0.50 D of myopia progression the year preceding the start of the study.
One group of children wore conventional single vision eyeglasses, a second group wore bifocals, and a third group wore bifocal lenses with prism. After three years, children who wore either type of bifocal eyeglasses had significantly less mean progression of nearsightedness (-1.01 D to -1.25 D) than children who wore single vision lenses (-2.06 D).
Detecting Myopia Early
The best way to take advantage of methods to control myopia is to detect nearsightedness early.
Even if your child is not complaining of vision problems (nearsighted kids often are excellent students and have no visual complaints when reading or doing other schoolwork), it’s important to schedule routine eye exams for your children, starting before they enter preschool.
Early childhood eye exams are especially important if you or your spouse are nearsighted or your child’s older siblings have myopia or other vision problems.
What About Myopia Control in Adults?
Myopia typically develops during the early school years and tends to progress more rapidly in pre-teens than in older teenagers. This is why myopia control studies usually involve relatively young children.
While it’s true that myopia also can develop and progress in young adults, this is less common. And it’s possible that an adult’s eyes may not respond to myopia control treatments the same way a child’s eyes do. For these reasons, it’s likely that most research on controlling myopia progression will continue to focus on nearsighted children rather than adults.
Can Eye Exercises Cure Myopia?
Some of these eye exercise programs recommend you ask your eye doctor to write you an eyeglasses prescription that intentionally under-corrects your nearsightedness for full-time wear as an adjunct treatment to performing the exercises. The claim is that the exercises and undercorrection of your myopia will reduce your nearsightedness, so you will need less vision correction as time goes on.
It’s worth noting here that research has shown undercorrection of myopia is ineffective at slowing myopia progression and may in fact increase the risk of nearsightedness getting worse. Also, intentional undercorrection of myopia causes blurred distance vision, which may put your child at a disadvantage in the classroom or in sports and affect their safety.
My opinion (and the opinion shared by most eye doctors and vision researchers) is that eye exercises do not cure myopia, are highly suspect, and are not supported by well-designed independent research. Buyer beware!
Ortho-k And Corneal Refractive Therapy: Overnight Contacts To Correct Myopia
It might sound far-fetched, but it’s a reality for many people. It’s called orthokeratology, or ortho-k.
Here are the top 10 things you should know about orthokeratology:
1. What Is Ortho-k?
Orthokeratology (ortho-k) is the fitting of specially designed gas permeable contact lenses that you wear overnight. While you are asleep, the lenses gently reshape the front surface of your eye (cornea) so you can see clearly the following day after you remove the lenses when you wake up.
Ortho-k lenses are prescribed for two purposes:
- To correct refractive errors (primarilynearsightedness, but also astigmatism andhyperopia). In some cases, ortho-k also is used to correct presbyopia.
- To slow the progression of childhood myopia. (Read more about myopia control.)
Ortho-k lenses are also called “corneal reshaping contact lenses” or “overnight contact lenses to correct or control myopia.”
One specific brand of ortho-k lenses and fitting technique is Bausch + Lomb’s Vision Shaping Treatment (VST). But ortho-k can be safely and successfully performed with other gas permeable (GP) lenses and corneal reshaping fitting techniques.
Only highly “breathable” GP lenses that have been FDA approved for overnight wear should be used for orthokeratology.
2. What Is Corneal Refractive Therapy (CRT)?
Paragon CRT (Paragon Vision Sciences) is a specific brand of corneal reshaping lenses that has a proprietary lens design and fitting methodology, called corneal refractive therapy (CRT). Though technically different than orthokeratology, CRT is used for similar purposes and produces comparable results.
For simplicity, I’ll be using the terms “orthokeratology” and “ortho-k” to describe all types of corneal reshaping lenses — including corneal refractive therapy lenses — in this article. Your eye doctor will determine which type of corneal reshaping lenses are best for you after examining your eyes.
3. How Long Does The Ortho-k Effect Last?
You should be able to see acceptably well without glasses or contact lenses for a day or two, sometimes longer. For best results, you should wear the ortho-k lenses every night.
4. Which Vision Problems Can Ortho-k Correct?
Orthokeratology is most frequently used to temporarily correct myopia (nearsightedness). Generally, ortho-k can correct upwards of -6.00 diopters (D) of myopia.
Ortho-k also can correct lesser degrees of astigmatism, hyperopia and presbyopia.
The type and amount of refractive error that can be effectively managed with orthokeratology differ on a case-by-case basis. Your eye doctor will be able to give you more specific guidance after examining your eyes.
5. Who Is a Good Candidate for Orthokeratology?
Most people with mild to moderate myopia (with or without mild astigmatism) are good candidates for ortho-k.
Because the corneal reshaping effect is temporary, little risk is involved, and you can discontinue wearing the lenses at any time — provided you are willing to start wearing glasses or contacts again when your myopia returns!
Children and young adults who want to be glasses-free but are too young for LASIK or are not good candidates for refractive surgery for other reasons (dry eyes, for example) often are good candidates for ortho-k. People who participate in contact sports or work in dusty environments that can pose problems for contact lens wear also can be good candidates.
6. Who Fits Ortho-k Lenses?
In the United States, optometrists perform most orthokeratology lens fitting. But ophthalmologists also perform ortho-k fittings. In some cases, ortho-k may be performed by a contact lens technician under the supervision of an optometrist or ophthalmologist.
It is important to know that orthokeratology is a very specialized type of contact lens fitting, and not all eye doctors who fit contact lenses also fit ortho-k lenses. If orthokeratology interests you, seek the services of an eye doctor who specializes in fitting these lenses.
7. What Results Can You Expect From Ortho-k?
Eye care practitioners usually aim for 20/20 vision after ortho-k, but 20/40 vision (the legal minimum for driving in most of the United States) often is considered an acceptable outcome.
In the FDA clinical study for approval of Paragon CRT lenses, 93 percent of patients achieved 20/32 vision or better, and 67 percent achieved 20/20 or better. In the clinical study for FDA approval of one VST design, about 95 percent achieved 20/40 or better, and 73 percent achieved 20/20 or better. Both studies followed patients for at least nine months.
8. What To Expect When You Begin Ortho-k
The eye doctor will begin by measuring the curvatures of your corneas using an instrument called a corneal topographer — a painless procedure that takes about a minute and produces a topographical map of your eye’s surface.
Your doctor might use an in-office inventory of lenses for fitting your eyes with ortho-k lenses the same day corneal topography measurements are taken, or he or she may order custom ortho-k lenses for fitting at a later date.
You may need a series of temporary lenses to see properly until you reach the desired prescription. In most cases, up to three pairs of lenses are required to achieve the maximum vision correction effect.
When you begin to wear ortho-k lenses, you will likely have some awareness of the lenses on your eyes until you fall asleep. With time, the lenses typically become more comfortable immediately upon insertion.
9. How Long Does It Take For Maximum Ortho-k Effect?
This depends on many factors, especially the amount of nearsightedness (and possibly astigmatism) you have when you begin the ortho-k process.
Some people can have excellent vision after a day or two of overnight ortho-k. But for higher prescriptions it can take two weeks or longer for maximum correction.
Until your eyes are fully corrected, you might notice blurred vision and glare and halos around lights. In some cases, you may need to wear glasses (with a lesser prescription than you originally had) during the ortho-k process. Also, in some cases, mild glare and halos might persist even after maximum ortho-k correction.
10. How Much Does Ortho-k Cost?
Fitting ortho-k lenses is a more time-consuming process and requires more expertise than fitting regular contact lenses. It requires a series of office visits and potentially multiple sets of lenses.
Each eye care practitioner determines his or her own fees for orthokeratology, based in part on the doctor’s level of expertise, time required and lens costs.
The cost of ortho-k, including follow-up care associated with fitting the lenses, can vary significantly depending on the type and degree of your refractive error and whether you are choosing ortho-k lenses for long-term myopia control in addition to the temporary correction of existing myopia.
Costs also can vary based on the region of the country, urban vs. rural settings, and the type of practice where you have the procedure performed.
Ortho-k prices in the U.S. generally range from $1,000 to $2,000 (for both eyes), making the procedure roughly half the cost of LASIK. But particularly difficult cases of ortho-k can cost as much as $4,000.
There are additional costs for replacement ortho-k lenses, lens care solutions and follow-up exams, which can total about $300 to $500 per year.
Normally, orthokeratology is not covered completely by vision care insurance plans, but a portion of the fees may be covered by some plans.
Bonus Q&A: Can I Have LASIK After Ortho-k?
Yes, it’s possible to have LASIK after ortho-k if you later desire vision surgery to permanently correct your eyesight.
Unlike LASIK, ortho-k is reversible. If you try reshaping lenses and later decide you want laser eye surgery instead, you can do that.
But you will have to discontinue wearing the lenses and wait a period of time before surgery (possibly several months) to allow your corneas to fully revert to their pre-orthokeratology shape.
Finally, keep in mind that, as with all contact lenses, there are some possible side effects and complications of wearing ortho-k lenses. Ask your eye care practitioner for details.