Myopia Control – What Works Best???
At Mark Hinds Optometrists we have a myopia clinic where our goal of treatment is to do our best to prevent the progression of myopia.
Some children (and adult) eyes develop myopia and the percentage of people who develop it is increasing sharply. Myopia prevalence is increasing around the world, even to the point of being called an epidemic by some. In some parts of Asia, 80% of the children in high school are myopic. Myopia is particularly prevalent in Australian students from Asian migrant backgrounds, which culturally place a high value on education. 60% of 17-year-old students of East Asian background are short-sighted, compared with 18% of children of European ancestry.
Research is showing that that there are methods to slow or prevent the progression of myopia, but the actions work best when the child is younger and/or the degree of myopia is less. Myopic changes are generally permanent; they don’t get better with treatment. Treatment should therefore be designed to prevent the development and progression and to do that requires eye examinations to start at a young age, approximately five years old for yearly exams.
While myopia may be a growing phenomenon, it can be readily corrected with glasses and contact lenses; and refractive surgery can provide a near-permanent correction. Why then is myopia control (as distinct from myopia correction) important?
First, there are enormous social and personal costs to myopia. The hundreds of millions of people around the world who wear glasses or contact lenses would be much happier if they could be less dependent on these devices—and they would collectively save billions of dollars in the process. In addition, myopia, especially high myopia, is not benign: it is associated with increased risk of retinal detachments, myopic degeneration, myopic macular hole formation, glaucoma, myopic retinopathy, posterior vitreous detachments and other serious ocular morbidity. Some have called this driving a car without a seat belt on – it does not mean that a bad thing will happen but high myopia certainly carries with it more risk.
Most important, myopia control is becoming possible. Once thought of as almost solely a product of genes, it is now clear that myopia development has a very large environmental component. With myopia rates rising rapidly around the world, we have to ask: What global change in the human environment is driving this? Beginning in early childhood, the onslaught of near-vision demands from books, computers, video games, and hand-held devices has an effect on how eyes develop.
Additionally, there is a high correlation to lack of outdoor (UV light exposure) activity and myopia progression. Based on epidemiological studies, Ian Morgan, a myopia researcher at the Australian National University in Canberra, estimates that children need to spend around three hours per day under light levels of at least 10,000 lux to be protected against myopia. This is about the level experienced by someone under a shady tree, wearing sunglasses, on a bright summer day. (An overcast day can provide less than 10,000 lux and a well-lit office or classroom is usually no more than 500 lux.). Three or more hours of daily outdoor time is already the norm for children in Morgan’s native Australia, where only around 30% of 17-year-olds are myopic. But in many parts of the world — including the United States, Europe and East Asia — children are often outside for only one or two hours.
THE BOTTOM LINE
Myopia prevalence is increasing rapidly around the world. East Asia is the most affected region, but rapidly rising rates of myopia can be found throughout the developed world. Research in animal models has shown that axial elongation can be triggered by hyperopic blur in the peripheral retina. The explosion of near-vision tasks to which children have been subjected in developed countries is thought to be behind the rising rates of myopia.
Both pharmaceutical intervention and overnight orthokeratology have been shown effective in slowing myopia progression in children. Atropine is an eye drop that may be used in low concentration (0.01%). Atropine drops in this concentration have been shown to slow the progression of myopia / nearsightedness by 61%. Among the demonstrated safety and efficacy, there are many good reasons for optometrists and ophthalmologists to consider adopting orthokeratology in their practices.
Mark Hinds Optometrists’ Approach
We are highly experienced orthokeratology practitioners with extensive fitting sets, hundreds of patients in this modality of wear, lectured at international conferences on this topic and been teaching in this area at university since 2003. We are active members of the Orthokeratology Society of Oceania. With this experience and evidence based medicine we firmly believe that this is often an effective approach to myopia progression prevention / myopia control.
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