Myopia (Nearsightedness) Overview
Myopia is the most common cause of impaired vision in people under 40, and prevalence is growing at an alarming rate. Research suggests that in the year 2000, about 25% of the world’s population was nearsighted. By the year 2050, researchers believe that roughly 50% of people in the world will be myopic. A change of this magnitude in area of health is unprecedented.
Myopia occurs when the eye is too long relative to the focusing power of the cornea and lens of the eye causing blurred distance vision. Myopia can also be caused by the cornea and/or lens of the eye being too curved for the length of the eye. Sometimes, nearsightedness occurs due to a combination of these factors.
Risk Factors for Myopia Progression
- Patients with one or both parents being myopic are more likely to develop myopia
- Excessive near work
- Limited time outdoors
- If the patient is more myopic than the age expected normal
- Less than age expected hyperopia (farsightedness)
- The progression of myopia is more than 0.75 diopters (D) per year
Why is it a concern?
One of the reasons for myopia progression is that the length of the eye becomes longer (axial length) causing the retina to stretch and become thinner. Excessive stretching and thinning of the retina will make the eye more susceptible to complications such as retinal holes and tears that can lead to a retinal detachment – resulting in total or severe vision loss in rare cases. Glaucoma – a condition of progressive peripheral vision loss – is also more common in myopic individuals. Myopic macular degeneration, which is similar to age-related macular degeneration, can cause central vision loss. Reducing myopic progression by as little as 1 diopter can reduce these risks by 40%.
I/my child is not myopic, what should I do to prevent me/them from developing myopia?
First, you or your child should have an annual ocular wellness exam to assess your/their personal risk factors for developing myopia. It is recommended and encouraged to have outdoor activity anywhere from 90 to 120 minutes a day. Research suggests distance viewing and exposure to natural light can reduce the prevalence of myopia. So plan on spending as much time outdoors as you can and don’t forget your sunglasses! Also, limiting near work like hand held electronics to 2 hours a day, as well as taking visual breaks every 20 minutes can be helpful. We like to suggest the 20/20/20 rule: every 20 minutes, take a 20 second break and look 20 feet away. It’s also recommended to use a safe working distance for reading and handheld electronics. We recommend performing near point at the Harmon distance, which is the distance from your eyes to your elbow when your fist is on your chin.
I/my child is already myopic, what can I do?
While we cannot stop myopia from progressing, we are able to slow the progression by a significant amount. The most effective methods involve the use of soft multi-focal contact lenses or MiSight soft contact lenses, bifocal glasses, an eye drop (atropine), and corneal reshaping technique (orthokeratology). Our doctors will be able to guide you to the best option or options for you or your child. These myopia treatments have been shown to reduce a person’s myopia progression by up to 60%.
Myopia Control Methods:
- Soft Contact Lenses – There are specialty soft multifocal contact lenses that are designed to allow the patient to focus more easily at all distances while slowing the progression of myopia. These lenses have two treatment zones that create myopic defocus which make the image focus in front of the retina. It is believed this is the mechanism that slows axial elongation.
- Atropine Eye Drops – Low concentration (0.01%) atropine has been shown to significantly slow the progression of nearsightedness without increasing pupil size or decreasing near vision dramatically. While this has been proven to be effective in many peer-reviewed studies in multiple countries, this is still considered off-label use. In a large study, a very small percentage of patients reported symptoms of light sensitivity and mildly blurred near point vision.
- Bifocal or Progressive Glasses – The glasses are worn during the day for clear vision for both objects far away and near point. Generally they are worn every day although occasionally a day without the glasses will not adversely affect the treatment. Objects in the distance are viewed in the upper portion of the lenses and objects nearby are viewed through the lower portion. The lenses are worn as long as myopia progression is considered a risk.
- Corneal Reshaping (Orthokeratology) – Corneal reshaping contact lenses are worn during sleep and removed in the morning; these lenses temporarily change the shape of the cornea, so that the patient can see clearly all day long without glasses or contact lenses. During the first two weeks of overnight lens wear, you or your child will experience temporary changes in vision. If the vision changes are significant, you may need supplemental glasses to provide clear, comfortable vision. Although the chance of eye infection is still very low (about one case per 500 years of wear), it is greater for corneal reshaping contact lenses than usual daytime contact lens wear because the contact lens is worn overnight.
How long do I/my child need to be treated?
Research does not have strict guidelines on how long people should be treated with myopia prevention methods, but the general consensus is that people should be treated until they are at least in their mid-teens or longer, or when myopia progression is less than or equal to -0.25 diopter per year. Other research suggest stopping treatment when the progression of myopia stops.
Myopia control does not eliminate or reverse any preexisting myopia. It also does not guarantee eliminating the need for vision correction such as glasses or contact lenses.
Does my insurance cover myopia control treatment?
Not specifically, if you have a discount vision plan (VSP, EyeMed, VCD, etc.), it may cover a portion of your eyewear and/or contact lens cost.