Myopia, also called short-sightedness is one of the most common vision conditions (behind the retina.) It causes blurry distance vision, while objects up close remain clear and in focus. This most happens because the eyeball grows longer than normal. Physically, it means when light enters the eye it focuses in the front of the retina instead of on it (with long sightedness or hypermetropia it focuses behind the retina).
Myopia is becoming more widespread and is reaching epidemic proportions as people spend more time focusing on close work using their digital devices.
Once Myopia starts in early childhood it will usually progresses every year until it may stabilise in the mid-20s.
As the Myopia goes up and reaches -5.00D or greater, it is also increases the risk of future eye diseases. These diseases are glaucoma, cataract, macular disease and retinal detachment.
Myopia is defined as having a focusing or refractive error of at least -0.50D in one or both eyes.
The opposite of Myopia is Hyperopia (also called Hypermetropia or long sightedness), which means having a refractive error of +0.50 or greater. Hyperopia can cause blurry close vision as with reading or even computers.
Higher levels of Hyperopia may cause blurry distance as well.
Optometrists distinguish between Myopia and Hyperopia during an eye examination. One condition may mimic the other and several specialised tests may be necessary. Reading letters on a GP’s chart or at a school vision screening will not give any information or diagnosis about what the person’s eye condition is.
Myopia generally develops in the childhood teenage years and this can be influenced by a combination of genetics, environment and other visual characteristics.
Some children are more at risk of developing myopia compared to others. Having any of the following risk factors puts a child at an increased risk of developing Myopia:
Age
The earlier the myopia begins the quicker the progression
Family History
Having 1 myopic parent = 3X higher risk (2 parents = 6X risk)
Ethnic Background
Myopia is much more common in children of East Asian descent.
Refractive Error
Children should be normally long-sighted (hyperopia).
Time Spent Outdoors
Less than 1.5 hours per day increases Myopia risk.
Time Spent on Near Work
More than 2.5 hours per day increases Myopia risk
Unfortunately, even a small amount of Myopia increases the risk of many eye diseases. The higher the Myopia, the higher the risk.
Here are some examples of increased risk, compared to someone that does not have Myopia:
| Amount of Myopia | Retinal Detachment Risk | Glaucoma Risk | Cataract Risk |
|---|---|---|---|
| -1.00 to -3.00 | 3.1X higher risk | 4X higher risk | 2.1X higher |
| --3.00 to -6.00 | 9X higher risk | 4X higher risk | 3.1X higher |
| -6.00 to -9.00 | 21.5X higher risk | 4X higher risk | 5.5X higher |
| 9.00 or greater | 44.2X higher risk | 4X higher risk | 5.5X higher |
| Macular disease | Risk level |
|---|---|
| -1.00 to -3.00 | 2.2X higher risk |
| -3.00 to -6.00 | 10-40X higher risk |
| -6.00 to -9.00 | 127X higher risk |
| -9.00 or greater | 349X higher risk |
| Treatment | Effect on slowing down myopia |
|---|---|
| Qrthokeratology lenses | 30-56% |
| Multifocal soft contact lenses | 25-72% |
| Atropine eye drops | 34-96% |
| Progressive glasses | 11-33% |
In this practice the multifocal soft contact lenses approach is used with good results.
But there is light at the tunnel; there are simple strategies that can delay the onset of Myopia down once it starts. Delaying or preventing Myopia can reduce the risk of getting high Myopia, and thus reduce the risk of future eye disease.
Spectacle correction can make the distance vision clear, but they do not stop myopia from getting worse. Myopia control treatments aim to slow down or stop Myopia from getting worse.
To get a better idea how the strategies listed below can slow you or your child’s Myopia, you can use a Myopia Calculator.
(https:/calculator.brienholdenvision.org/)
For professional diagnosis of myopia in South Yarra and St Kilda, get in touch with us today to book a professional consultation.