Myopia Control Options
What is Myopia?
Nearsightedness, or myopia, as it is medically termed, is a vision condition in which people can see close objects clearer or less blurry than objects far away. Myopia occurs if the eyeball is longer than the focal point of the eye, which is related to the focusing power of the eye. To correct myopia, concave or minus-powered lenses are used to move light rays to the retina creating a clearer image as shown in image 1.
What causes Myopia progression?
There are no shortage of theories on the mechanisms of myopia development and progression. One thing we do know is that simply correcting myopia causes a peripheral hyperopic defocus as demonstrated by image 2 that causes a stimulus for further increase in axial length that leads to increased myopia as demonstrated in image 3. Thus, improving vision and reducing myopia can make it worsen requiring more correction, and then the cycle begins again. Thus, creating peripheral myopic defocus instead of peripheral hyperopic defocus using techniques like orthokeratology and multifocal glasses/contact lenses can provide a huge benefit in slowing myopia progression.
Myopia still progresses even with peripheral myopic defocus techniques, so what is too blame? Genetics, near work, time indoors, artificial lighting, and even diet have been investigated for their potential relationship to myopia. This leads to the classic nature versus nurture argument. Statistics prove that nature has an impact. For instance, if one parent is nearsighted, the child has a three times greater risk for developing myopia. That number doubles to a six times greater risk of developing myopia if both parents are nearsighted as shown in image 4.
However, nurture seems to be more to blame as evidenced by the increasing prevalence of myopia throughout the world. According to predictions based on current trends, half the world’s population will be myopic by 2050 as shown in image 5. So if the environment is the culprit, then what potential factor is to blame? Is it the light? …the near work? …the lack of exercise? …the diet? As of right now we don't know, but does it really matter? Isn't it more important to do what we can to minimize myopia progression?
Why Prevent Myopia progression?
The fact of the matter is that myopia is very complex and not fully understood. Fortunately, there are a number of options we can use to help slow myopia progression, even if we don’t know the exact mechanism of action. But, why should we care so much about slowing myopia? As the amount of myopia increases, the likelihood of developing a number of ocular diseases (i.e. cataracts, glaucoma, retinal detachment, and myopic maculopathy) increases, sometimes dramatically as shown in image 6.
Thus, treatment and intervention now can reduce risk of ocular pathology later in life. Additionally, quality of life benefits are huge with myopia control. For example, a -2.00 myope is much more functional uncorrected than a -6.00 myope. Basically, it is the difference between reading comfortably without correction and being completely reliant on correction all waking hours. So, what can be done?
How to Minimize Myopia progression?
1) Lifestyle Modification
Our modern lifestyles are clearly to blame for the increase in myopia prevalence, which is why it is recommend that kids minimize time on their digital devices and maximize time running around, playing in the dirt, and soaking up the sun. Additionally, eating healthy meals of minimally-processed, whole foods, and getting good sleep are important, but aren't these recommendations typical for raising healthy kids? Basically, the old wives' tale that spending too much time in front of the TV will ruin your eyes has some merit - it can cause increased nearsightedness. Live healthy, be healthy.
2) Update Glasses/Contact Lens Prescription
Studies show that wearing an old/under corrected prescription can actually cause myopia to progress more quickly, so at the very least update glasses and contact lens prescriptions regularly. Single vision contacts and glasses cause fairly similar rates of progression with glasses being a little worse (about 0.75D a year on average).
3) Multifocal Glasses
For patients with esophoria (a specific eye-muscle positioning) studies have shown that a pair of multifocal glasses (progressive, bifocal, Sync lens, etc.) can help reduce myopia progression compared to a single vision pair of glasses. Two of the theories of myopia progression (are addressed by multifocal glasses, which may explain their benefit in preventing myopia progression in these patients. There is no risk with this option, but there is some downside in the form of cosmesis, expense, or both. Our clinic typically recommends using a Sync lens to provide a plus add effect at the bottom of the lens in a similar fashion to a bifocal without as much of a cost to the patient and their family.
4) Multifocal Contact Lenses
With multifocal soft contact lenses, the optics presented to the eye are similar to those of orthokeratology. Studies show that traditional distance-centered multifocal contact lenses slow myopia progression by nearly 50%. Meanwhile, MiSight by CooperVision is a daily disposable soft contact lens that is specially designed to slow myopia. Early studies indicate a nearly 60% success rate with good comfort and vision reported. Our practice is a Brilliant Futures Myopia Management Program provider. To find out what that means, contact us to set up an appointment for a myopia management evaluation today.
5) Orthokeratology (Ortho-K)
This process gently reshapes the cornea while you sleep, and can greatly slow down, or even stabilize nearsightedness. The best part is that when you remove the reshaping contact lenses in the morning, you can visually function all day long without having to wear glasses or contact lenses. Early studies showed an approximately 45% halt in myopia, but with the advances in Ortho-K this number has been found to be much higher. Click to read more about Ortho-K.
Low dose (0.01-0.05%) Atropine is the ideal choice for children that are too young to use Ortho-K or specialty lenses. Additionally, it can be effectively combined with other methods of myopia control. Ease of administration is a huge benefit to using low dose atropine for myopia control, as it only requires one drop in each eye daily. Recent studies show that low dose atropine doesn't share the same side effects as higher concentration atropine, but will cause a small amount of pupillary dilation. In some studies, low dose atropine has been shown to be the most effective way of controlling myopia.