What is myopia control?
General Information on Short –Sightedness or Myopia
Images should be focused on the retina in a normal eye. In myopia the image is focused in front of the retina causing blurred vision. This can be as a result of a growth in the length of the eyeball.
Prevention is better than cure
It is better to try and prevent a child becoming short-sighted (myopic) as myopia can not be reversed. It is more difficult to slow the progression of short-sightedness (myopia) than to prevent myopia occurring in the first place. It is predicted that 50% of our children will be myopic by the year 2050.
Risks of a Child becoming Myopic
A. 1 parent -3 times more likely to be myopic
B. 2 Parents -6 times more likely to be myopic
C. Ethnicity –Asian children are more likely to be short-sighted
D. Little time spent outdoors
E. Excessive time spent indoors on near tasks
Problems Associated with higher levels of Myopia
Condition Risk at -4.50 Risk at -6.50
Myopic Macular Degeneration 9.7 times more likely 40.6 times more likely
Retinal Detachment 9.0 times more likely 21.5 times more likely
Cataract 3.1 times more likely 5.5 times more likely
Time Outdoors Per day
Spending more time outdoors can reduce the risk of developing myopia by 50% due to the effect of natural daylight. Spending less than 1.5 hours per day outdoors is regarded a low amount of outdoor time, 1.5 to 2.5 hours is a moderate amount of time, and more than 2.5 hours is a high amount.
Sun Protection -Sunglasses /Hat
Even while wearing sunglasses and a hat the visible light levels reaching the eye is still far higher than that indoors. Thus your child is reducing the risk of developing myopia and also being protected from UV rays at the same time.
Time Spent on close work
Excessive time spent indoors on near tasks (for example tablet use, reading, jigsaws) increase the risk of developing myopia. With near work in leisure time, we regard less than 1.5 hrs as a low amount of near work, 1.5 to 2.5 hrs as a moderate amount and more than 2.5 hrs as a high amount.
None – no shift
Medium- 0.25 to 0.75
High- Over 0.75
Age 9 years old or younger
Refractive Error Less long sighted than normal for age
Parental Myopia 1 or both parents short-sighted
Ethnicity –Asian or Caucasian Asian children at risk
Time spent outdoors 1.5 hrs or less per day
Time spent on near Work 2.5 or more hrs per day
Myopia increase An increase of – 0.75 or more per year
New Thinking on Controlling Myopia
Ideally when glasses are worn the whole image would be in focus across the entire retina. Unfortunately with myopia the spectacle lenses only focus the image on the retina centrally. The periphery is out of focus behind the retina (peripheral hyperopic defocus). This peripheral hyperopic defocus seems to be a powerful stimulant to eye growth resulting in more myopia. Thus the problem can be never-ending unless we step in to discourage eye growth.
Once a child is -0.50 myopic and is at high risk, we can consider intervening to use some control strategy.
By Myopia control we not mean that the child will not develop more myopia, but rather reduce the progression by up to 50%.
Types of myopia control
A. Bifocals: The bigger the segment the better, but the bigger segments are more obvious. Can provide between 39-51% protection for the biggest segment (executive bifocal)
B. Progressive lenses: The least effective- provides about 15 to 25 % protection but cosmetically very good.
2. Contact lenses
A. Daily disposable Myopia Control Contact Lenses: Mysight Lenses. Can provide approx. 40% control. Low infection risk as contact lenses are thrown out at end of each days wear.
B. Monthly Disposable Multifocal contacts: can provide up to 40% control. Small risk of infection as same contacts are used for a month. Lenses are cleaned and stored each night.
C. Ortho K -Overnight wear of hard Gas permeable contact to mould the shape of the front of the eye. Generally no glasses are needed during the day .Can provide up to 41% control. Generally, no glasses are needed during the day.
When do we stop treating myopia?
When your child’s vision is stable for 2 years or more we can revert back to straight forward glasses and/ or contact lenses.
Myopia Control at Elliott Opticians
Our optometrists Rena and Elaine are trained in myopia control and will be very happy to discuss the options that are best for you or your child. Please call the office on 09064 76111 to make an appointment.