Why worry about Myopia?
Myopia (short-sightedness) generally begins in childhood and develops through adolescence. It is easily corrected with spectacles or contact lenses, so why should we try to slow its progression?
Although low degrees are not a major problem with vision, people with higher degrees of myopia can be quite handicapped when not wearing glasses; they may be unable to see the clock when they wake in the night or to find their way around the swimming pool. Spectacle lenses will be thicker and heavier. Even more importantly it has been shown that being short sighted increases the risk in later life of developing Cataract, Glaucoma (eye pressure disease) and Retinal Detachments. Even low levels (-1.00) double the risk of Retinal Detachment.
If myopic progression can be slowed so that the final adult degree is reduced, the risk of eye disease will be lower and the quality of life improved.
Traditionally vision correction has concentrated on focussing images on the central retina which gives us our sharpest vision. However recent research suggests that the way in which light is focussed in the peripheral retina may be a very important factor in myopia development. For children who are becoming myopic it seems that the peripheral image focus is behind the retina and that this might trigger the eye to elongate, causing the myopia to increase. This is explained in more detail on: www.myopiaprevention.org.
By causing peripheral defocus it has been shown that on average myopic changes can be halved. This means that instead of becoming highly Myopic with the associated problems, most people can remain in the low to medium category resulting in significant visual, health and self esteem benefits.
Recent advanced developments in manufacturing techniques have made possible the creation of contact lenses able to correct peripheral defocus and thereby reduce the progression of myopia.
Since May 2018 we have now received access to the Worlds first Daily Contact lens designed for Myopia Management, developed to correct peripheral defocus. We also have access to two other approaches, using types of contact lenses in current use, that also address this problem; Orthokeratology, (Ortho-K,) and Multifocal contact lenses.
MiSight Daily Myopia Control Lenses – “Product of the Year 2018”
MiSight contact lenses are now available from Brown and White Opticians. They have been available in Asia since 2009 on a limited basis. We have been specially selected to be able to fit these in advance of general release in the UK . Daily lenses are comfortable, with low risks of infection, safe and easy to use even for very young children and these lenses are the only lenses available that have been specifically designed to manage myopia in children. Their average effectiveness is 59% and are recommended in all cases of myopia from -0.25 up to -6.00 Diopters of Myopia with small amounts of astigmatism.
This involves fitting precisely manufactured rigid gas permeable contact lenses which are worn overnight to reshape the cornea in a way that corrects the myopia. This reshaping is temporary and lasts for a day or two, so as long as the lenses are worn overnight no glasses or contact lenses are needed during the day. Ortho-K can reduce the progression of myopia by between 32% and 63% with an average of 43%. This is a specialised fitting procedure and can take some tome for the vision to stabilise. Better reductions are found in people who have prescriptions above -2.50 and below -5.00 Diopters of myopia with small amounts of astigmatism.
Multifocal contact lenses
Some types of monthly changing but daily wear multifocal contact lenses can be used to correct peripheral defocus in myopic children. These soft lenses are worn during the day. They are comfortable and give good vision so they are popular with children. The early results are very encouraging, indicating that myopia progression can be reduced by about 49%. Young children can be started on this type of lens. The powers available with this type of lens can cover all levels of myopia and astigmatism.
Risk factors for Myopia
There is a strong genetic component to myopia and children with two myopic parents are up to seven times more likely to develop myopia than those with neither parent affected.
Intensive reading and other close up tasks, (including mobiles, electronic games and ipads) may be a contributory factor. This has led to large studies into the use of bifocals and varifocals to reduce the amount by which the eyes have to focus during near vision.
Research shows that myopia develops more slowly in children who regularly spend time outdoors. It is thought that exposure to outdoor light inhibits the elongation of the eye, which is the cause of myopia.
In China, in schools that had an extra 80 minutes of outdoor activity put into their day, there was a 23% reduction in the rate of myopic increase and a 50% reduction in new cases of Myopia. Research is currently being undertaken into glass walled bright sunlit classrooms.
It has been found that Executive Bifocals can help reduce myopic progression by 39-45%. They are particularly effective in the minority of children who have a condition called Near Esophoria, where the muscles tend to work too hard when looking close. Testing for this is part of your child’s routine eye examination with us. Progressive lenses (varifocals) can also be effective, giving a reduction in progression of up to 29%.