WHY DOES MY NEARSIGHTEDNESS KEEP INCREASING?

Myopia, or nearsightedness, is a very common visual problem where people have difficulty seeing at far distances, while near distances are easier to see. This post will discuss why we should be aware of changes, why these changes happen, and how to slow down the progression of myopia.

It can be fairly easy to get myopia treated by having an eye exam and purchasing a pair of glasses. “Voila! Now you can see at distance. No problem, right?” The answer to this is difficult, and in short, “It depends.” About 28% of the entire population has myopia, and is expected to double by 2050. Eyecare professionals used to treat myopia with glasses and standard contact lenses, but with new research, we now have options that aggressively combat myopia, slowing the progression, and stabilizing our patients’ prescriptions.

So the prescription gets higher… why do we care?

Yes, the glasses will get thicker, and yes, they will be more expensive. Much more importantly, with the stretching of the eye, the health of the eye changes, and there is a much higher risk for several eye diseases. These include retinal detachments, glaucoma, and a specific form of retinal degeneration (myopic maculopathy), all of which could cause permanent vision loss, regardless of the prescription or viewing distance.

Why does the prescription keep getting higher?

The simplest way to explain it is that people with myopia have longer eyes than most, so the only way for light to clearly focus on the retina is by moving closer to objects, or to have glasses shift the image to an accurate distance. There is a strong correlation between myopic parents having myopic children, and twin studies suggest that identical twins are more likely to have similar prescriptions compared to fraternal twins. This suggests that there is, in fact, a genetic component to myopia and its development. Lately, practitioners have viewed this as a “susceptibility factor” to myopia. The mechanism that causes the eye to elongate is now understood to be the peripheral retina receiving signals of blur, causing elongation. In uncorrected myopes, the central vision does not reach the retina, as described above. The peripheral images are still behind the eye. With glasses and standard contact lenses (traditional correction), the whole image is shifted to obtain adequate central vision, but the peripheral image is still behind the retina. The optimal correction has peripheral light landing inside the retina, which does not signal eye elongation. This is called “hyperopic defocus,” and is the basis of every available treatment that actively slows myopia.

Treatment Modes

Ortho Keratology (Ortho-K)

These are contact lenses that are custom made for each patient that are meant to be slept with overnight. While asleep, these lenses press on the front of the eye, reshaping it to achieve clear central vision. One of the powerful side effects of this eye reshaping is that peripherally, the images tend to land closer to the middle of the eye, decreasing the signal telling the eye to lengthen. When awake, the patient does not usually need to wear any glasses or contacts, so these are great for athletes, particularly swimmers. There is a limit on how high of a prescription that can be treated, so in some cases, additional power may be needed. These are very safe to sleep in, but the main drawback is cost, since these lenses are highly customized and specialized, and require much time and testing to properly fit.

Multifocal Contact Lenses

Designed to help patients that have age-related near vision issues, these specialty soft contact lenses have good central vision, but have concentric rings of alternating distance and near areas of vision. Essentially, it is creating areas of peripheral blur that land light in the middle of the eye and outside the eye. Although these may be blurry at first, Dr. Mark can modify them to make the most comfortable vision while maintaining effective myopia control. At this time, treatment of astigmatism is limited in these contacts, so patients with high astigmatism may need another route.

Atropine Eyedrops

This eyedrop is primarily used to dilate the eyes. In extremely dilute concentrations, this can moderately dilate the eye without the common symptoms of blurry vision and light sensitivity. This drop is used in both eyes before bed every night, and larger pupils cause the peripheral light to… you guessed it - land closer to the middle of the eye. There are possible side effects, but these are extremely rare with standard dosages of this drop, and essentially unheard of in dilute concentrations. The benefit of these are the cost and ease, and ability to use at any level of prescription.

Specialized Eyeglasses

Defocus Incorporated Multiple Segment (DIMS) eyeglasses are currently undergoing FDA approval and are not currently available in the United States, but are a strong potential option to manage myopia. Again, they act in the same way as the other options, bringing the peripheral vision inside the eye.

Lifestyle Changes

Recent research showed that nighttime mode/dark mode on phones help slightly to stabilize the progression of myopia. Clinically, we find that children that are farsighted, progressing toward no prescription, benefit greatly from outdoor time. That being said, the more outdoor time, the better. Researchers recommend 16 hours per week to optimally stabilize progression.

To see a very helpful infographic on myopia, visit www.mykidsvision.org

If you or your children are progressively increasing in nearsightedness, please come see Dr. Mark and chat about some options.