Low dose atropine can help, depending on eye colour, but heading outdoors is proven to work too.
Low dose atropine drops can help prevent myopia progression in children, but spending more time outdoors may be the most affordable and accessible treatment you can prescribe.
By 2050, half the world’s population is expected to have myopia, due to both environmental and genetic factors. Often referred to as short-sightedness, the condition worsens with continued eye growth. Around 10% will have “high” myopia, and half of those will develop “pathological myopia” (myopia with complications), which is expected to become the leading cause of permanent blindness.
Correcting vision alone does not slow myopia progression.
And while there are therapeutic devices such as defocus-incorporated multiple-segment lenses, multifocal contact lenses and orthokeratology (hard lenses that can be worn overnight), atropine is far better tolerated in young children aged 6-12, which is when myopia usually presents, than those devices.
Australia is one of the few countries to have approved atropine 0.01% (Eikance) eyedrops for myopia prevention.
It has been available on prescription since September 2021 (but not on the PBS) for children aged four to 14 whose myopia has progressed at one or more diopters per year, and the advice is that it needs to be used for two years to see the maximum benefit. It can be prescribed by paediatric ophthalmologists and optometrists.
The effect of low dose atropine on slowing myopia in kids, which has long been used by paediatric optometrists for treatment of other conditions and, by some, for myopia prevention, has been investigated in various trials around the world. Results have been mixed.
A US study published in June this year backed the use of low dose 0.01% atropine in young children.
“From a risk/benefit perspective … low-dose atropine may provide a treatment option for children aged three to 17 years with myopia progression, which may lead to less frequent or delayed change in glasses, progression to less severe correction, and potentially reduce long-term sequelae, which could lead to vision loss later in life, such as myopic maculopathy,” the authors wrote in JAMA Ophthalmology.
“Future studies of pharmacologic myopia control in US children should consider increased atropine concentrations, new pharmaceuticals, objective measures of treatment adherence, alternative eye drop delivery systems and schedules, as well as evaluating the impact of environmental and genetic factors and optical interventions on myopia control treatment,” those authors said.
But ophthalmologist Professor David Mackey from the Lions Eye Institute at the University of Western Australia, who conducted a trial in children in Western Australia, told TMR he found the second result surprising.
The Western Australian ATOM study, in which Professor Mackay was involved, found that the 0.01% atropine did make a difference. “But more importantly, within our study, we noticed there was a big difference between the Europeans and the South and East Asian children,” he said.
Progression significantly slowed for children from European backgrounds after 18 months. However, there was no effect for children from an East or South Asian background.
This supported previous trials on Chinese children that found a concentration of 0.05% had the greatest benefit with minimal rebound effect (where myopia progressed more quickly after treatment ceased).
“Studies conducted in Asia … may not be generalisable to other ancestries, as Asian children tend to spend less time outdoors and because darker iris pigmentations bind more atropine, resulting in lower drug availability within the eye,” Professor Mackey and his colleagues wrote in their 2022 study.
Professor Mackey suggested the results from the second US study, showing no benefit from 0.01% atropine, could also be related to eye colour.
“The size of the [latest US] study and mix of ethnic heritage might have been the reason why the American study did not find an effect; 0.01% is probably not effective enough in children of East and South Asian and probably African Americans,” he said.
A meta-analysis is currently underway to look specifically at this matter.
Additionally, the covid pandemic could have been a factor. It’s possible that exposure to sunlight is required to provide benefit from low dose atropine.
“The behaviour of children during this time changed in that they weren’t going outdoors. And that, we know, is one of the other protective mechanisms for myopia and myopia progression.”
Go play outside
It’s no coincidence that, as Professor Mackey noted, Western Australia has some of the lowest myopia rates in the world.
There is substantial evidence that bright light exposure can reduce myopia and may possibly occur even with brighter indoor lighting. Being outdoors also reduces exposure to peripheral defocus (where light enters the eye and falls behind the retina rather than on it, which progresses myopia but probably doesn’t bring it on).
Another possibility is that the chromatic spectrum of light – the wavelength – can affect the retina, and sunlight has more green, blue and ultraviolet lights than artificial lighting.
In Australia, that comes with trade-offs.
Data from the long-running Busselton Healthy Ageing Study has shown an inverse correlation between myopia and skin cancer, where the odds of not having myopia were three times higher for those with skin cancer. It also increases the risk of cataract and pterygium.
“Reassuringly, ultraviolet light exposure is likely not required for myopia protection; therefore, clinical recommendations or public health interventions to increase time spent outdoors are likely compatible with skin protection and sunglasses use, which do not reduce light intensity significantly,” Professor Mackey and his colleagues wrote in the ATOM study.
While children with myopia are generally treated by optometrists and ophthalmologists, Professor Mackey said treatment was available at public paediatric clinics.
“[However,] we have a huge problem in Australia, in that the public hospital, paediatric clinics are just overwhelmed,” he said.
In addition, buying 0.01% atropine treatment every month over a period of years could become quite expensive. And it’s not yet approved in Australia at a higher level of concentration. That would have to be made up by a compounding chemist at a much higher cost.
“[Low dose atropine] is probably worth trying for a year or two. But we have no idea whether this may be something that needs to go on for quite a long time,” Professor Mackey said.
“It probably is cheaper than getting the expensive glasses or the orthokeratology contact lenses. But the very cheapest treatment is spending more time outdoors and less time on computer screens.”