Myopia, also known as short-sightedness or near-sightedness, is a common condition where close-up vision is generally clear, but further away objects are blurred. The higher the degree of shortsightedness, the more blurry the distance vision. Shortsightedness can be easily corrected by wearing glasses and contact lenses, or even eye laser surgery for adults.
At The Myopia Clinic at Custom Eyecare we have a special interest in the prevention and treatment of myopia. For additional information about myopia, its causes and treatments available please visit our Myopia Clinic website.
What Causes Myopia?
The causes of myopia are complex and it’s an area of ongoing research, but in simple terms it’s a combination of both genetic (family history) and environmental influences such as the amount of time spent reading and on screens vs time spent outdoors.
Myopia Progression
Myopic patients are accustomed to being told their eyesight has deteriorated at their ongoing eye tests, that their prescription has increased and they need stronger glasses. Progressing myopia means that the eyeball is stretching as we grow, and worsening myopia means an elongated eye. Children, teenagers, and young adults seem to be the most susceptible to worsening vision from increasing myopia especially during the growing years. Simply accepting stronger and stronger lenses is no longer standard of care for shortsighted patients.
Slowing progression and myopia control is vitally important as stretching the sensitive retinal tissue is a risk to the future of your vision. Higher degrees of myopia are associated with serious eye conditions such as retinal detachments and glaucoma.
Customised eyecare that prevents or slows the progression of myopia is better than simply accepting stronger & stronger lenses. As behavioural optometrists, at Custom Eyecare we are more interested in the prevention of myopia rather than the easy option of simply prescribing stronger & stronger glasses.
Monitoring Axial Length
The first step in the management of myopia is a thorough myopia assessment including axial ocular length measurements. In 2020 we invested in technology that traditionally was only used by an ophthalmologist prior to cataract surgery. A Zeiss IOL Master assists eye surgeons accurately measure the eye, a vital measurement for calculating the lens power of the implant used in cataract surgery.
We are the only optometrist in Newcastle with a Zeiss IOL Master. We now use this technology routinely in practice. We now measure axial length, or eyeball length, on all children who visit us as it provides a valuable baseline to prevent future blindness, and to carefully monitor progression of shortsightedness.
Measuring axial length is a vital component of myopia control. Axial length of 26mm is considered a defining number in the literature, whereby risk of future visual impairment is considerably increased.
What is myopia? Watch this video:
Treatment for Myopia Progression (Myopia Control)
Historical treatments
Over the years there have been many studies and much debate and controversy in the area of myopia prevention.
Some people believe that not increasing the myopic prescription in glasses to the full strength, and accepting slightly blurry vision, will help the worsening shortsightedness, but this has been disproved. Also, as expensive as it is for parents to keep continually increasing the prescription of their child’s glasses, overestimating the script will only make the myopia worse too. Research has proven that both an undercorrection and overcorrection strategy actually speeds up the worsening of myopia. It’s important myopic children have the correct prescription in their glasses for optimum boost in their vision.
Historically, some optometrists have advocated prescribing multifocal lenses in glasses for myopic children. Whilst it certainly can’t hurt, it has minimal effect on controlling myopia progression.
Myopia control contact lenses
Besides medications, there are two excellent contact lens options for controlling myopia in children. These are Orthokeratology and MiSight contact lenses.
Whilst some parents may feel apprehensive about kids wearing contact lenses, it’s really important to consider contact lenses for young children with increasing myopia. It has been shown that the earlier children are when their short sightedness develops, the more risk of progression, meaning younger children are more likely to experience rapidly worsening eyesight.
Some parents may be concerned about the safety of soft contact lenses in children but the reassuring news is the studies show the incidence of any contact lens related events is much lower in 8-12 year old contact lens wearers, than in adult contact lens wearers.
Also, there is no physiological reason to wait until children are older. Studies have show that after ten years of contact lens wear, there was no difference in the frequency of adverse events between those fitted as children compared to those fitted as teens.
And if we focus on the benefits, contact lenses have been shown to improve a child’s quality of life, how they feel about their appearance, boost their self confidence and their participation in sporting activities.
Orthokeratology
Orthokeratology treatment involves the wearing of custom-made rigid contact lenses (or “moulds”) to gently reshape the cornea whilst we sleep. It’s the moulding on the peripheral cornea that reduces the worsening of short sightedness.
Orthokeratology lenses are applied to the eyes surface just before bed. On awakening, the lenses are removed and you can see clearly all day without glasses or contacts! So the contour change is the reason orthokeratology slows myopia progression, and the side benefit of that contour change means you can see well with the lenses removed.
Like orthodontists or orthopaedics, “ortho” means changing the shape of, and “kerato” is the Latin word for cornea. So an orthokeratologist changes the corneal contour and this anatomical change is the reason this treatment slows the progression of myopia. The main difference is your bones and teeth are rock hard and once they are firmly moved in position, they don’t tend to move back. Our corneas are soft and elastic, so the Ortho-K lenses must therefore be worn every night to preserve and maintain the corrected corneal shape. Think braces magic at first, and a teeth “retainer” when you sleep in the lenses each subsequent night.
It is a very effective treatment for controlling myopia as it creates an imprint on the cornea. The imprint persists, provided you keep sleeping in the lenses, and washes away when you stop. Within a week of no lens wear, the cornea bounces back to its natural shape and former prescription. So it’s beauty is it’s reversible, adaptable to script changes, and surgery free.
Ortho-K isn’t new. The moulding effect of the cornea induced by contact lenses was learnt in the 1940’s. Since then, the technology, accuracy and safety of orthokeratology has dramatically improved. Our ability to accurately map the corneal changes, along with the development of new contact lens materials that allow extremely high levels of oxygen to reach the cornea, and the introduction of computer-controlled precision lathes that manufacture these corneal moulds to exact design specifications, have meant its popularity has grown.
Orthokeratology has been a very successful, well researched, effective treatment for myopia control for over 20 years. OrthoK has been shown in scientific studies to significantly slow down the progression of myopia. At Custom Eyecare, we’ve found in most patients it nearly always STOPS vision from getting worse.
Orthokeratology is suitable for all ages but it has a special advantage of slowing myopia progression in children & teenagers.
Want to hear more about the age limit for Ortho K? Watch this video:
MiSight Daily Contact Lenses
Another proven treatment in the fight against myopia progression is daily-wear soft contact lenses specifically designed for controlling short sightedness.
MiSight 1 day contact lenses by CooperVision are an innovative soft contact lens designed for myopic children and are worn during the day. A brand new, fresh, sterile lens is applied to the eyes each morning so the children have good vision for school without the need to wear glasses.
The origin of MiSight soft contact lenses started at the University of Auckland, New Zealand in 2004 and was first released in Hong Kong in 2010. There was only limited availability in Australia and New Zealand from 2011 but that means there is now nearly 10 years of data and evidence that MiSight is an effective strategy at controlling myopia.
The clinical studies have demonstrated a sustained reduction in myopia progression over a three year period and reduced myopia progression by 59% and reduced axial elongation by 52%. Reduced axial elongation helps reduce the risk of myopia-related complications and vision loss later in life.
The front surface of the contact lens has dual power with a distance focus. This distance centre means the myopia is fully corrected for clear distance vision, but there is additional power within the lens design to control both axial elongation and myopia progression.
While we understand parents may feel apprehensive about their children wearing contact lenses to school during the day, the research shows that children often forget to take their glasses to school, and uncorrected refractive error increases risk of myopia progression.
Myopia control spectacle lenses
Management strategies have evolved and nowadays there are myopia controlling options for those myopic children who aren’t yet ready for contact lenses.
MiyoSmart lenses
MiyoSmart is an innovative spectacle lens for myopia control developed by The Hong Kong Polytechnic University for Hoya. The design utilises DIMS technology. Put simply, the central portion of the spectacle lens has the myopic prescription for clear distance vision, surrounded by a treatment zone that focuses the peripheral light inside the eye to control myopia progression. Unlike a contact lens, myopia controlling spectacle lenses don’t move with the eye, but the treatment zone has very little impact on vision, and a significant impact on controlling myopia.
Stellest lenses
In 2018, Essilor initiated a 3 year clinical trial in a joint partnership with Wenzhou Medical University, in China to develop Stellest lenses. Stellest lenses use HALT technology which basically means the design consists of rings of little lenslets to focus the peripheral light inside the eye to control myopia progression in a concentric ring pattern. Studies over 3 years show a significant reduction in both the refractive change (the prescription) and the axial elongation (eyeball length).
Pharmacological treatments
Atropine
Another option to slow myopia progression is the use of Atropine eye drops.
Atropine is a therapeutic eye drop which acts to relax the ciliary muscle, the muscle controlling our focussing, called accommodation. Whilst atropine was initially used to treat other conditions, it has been shown to have some effect in controlling myopia progression. Scientists are still unable to agree on just how atropine affects myopia progression, though they can agree that it works to slow myopic change. Most patients are instructed to simply put one drop into each eye before sleep, every day. Children using Atropine need to continue wearing their contact lenses or glasses to be able to see as Atropine does not correct vision during waking hours.
As Atropine is a prescribed medication, it requires a pharmaceutical prescription typically written by a therapeutically endorsed optometrist or eye surgeon. It can be a little difficult to source as low doses need to be specially compounded as they are not commercially available.
1% Atropine works well at slowing myopia progression but there can be significant drug side-effects of dilated pupils & glare sensitivity for patients.
From there, studies looked at the effectiveness of weaker concentrations of atropine. 0.01% atropine is considered safe for long-term use in children for myopia control, and is an approach that has also been advocated by paediatric ophthalmologists. Extensive clinical trials on children have shown little to no side effects or adverse reactions at this dosage.
Whilst initial studies for low dose Atropine looked very promising, over time the clinical evidence that supports the use of low dose atropine has been less convincing. We continue to read updated evidence, to ensure we provide the safest and most effective management options.
Preventing myopia
Outdoor time
Lastly, the cheapest and hopefully the easiest measure parents who are concerned about their children becoming myopic, is to send them outside!
Outdoor time has shown to be protective against the development of myopia in children & teenagers, regardless of how many hours are spent doing close work on screens.
A review of the literature showed that spending time outdoors was found to have a protective effect for the onset of myopia. This means outdoor time helps reduce the risk that children will become myopic. There is not yet enough data to be certain that increased time outdoors helps to halt myopic progression for those children who were already shortsighted, but the studies have found that shortsighted children spend more time indoors than hyperopic children.
Aside from the vision benefits, outdoor play is definitely a healthy habit to develop. There are numerous physical and psychological benefits to children getting outdoors and especially into nature.
The vision benefits aren’t simply related to just getting kids to take a break from reading and screens, nor is there a direct correlation to the actual physical activity done outdoors. It seems the secret is the brightness of outdoor light. Even on a cloudy day outdoors, and even with super bright artificial lighting indoors, outdoor light is many magnitudes brighter. This may be stimulating the young eye to grow at the correct rate, via a neurotransmitter in the eye and the brain called dopamine, and not at the accelerated rate as is the case in childhood myopia. It might also be about the process of looking far away, and having the whole of the retina (the light sensitive film at the back of the eye) stimulated in a more uniform way, compared to when we’re indoors and focussed on near reading and screens. In China, where the prevalence of childhood myopia is at 80%-90%, there are schools experimenting with glass-walled ‘Bright Classrooms’ to simulate outdoor lighting conditions inside where the students spend most of their days.
What can you do?
At Custom Eyecare, we recommend that all children, especially those at risk of myopia, spend some time outdoors every day. Ideally at least 90 minutes a day outdoors, even though this can seem hard to achieve in our busy lives.
Moderate to vigorous physical activity for at least 60 minutes a day is recommended for school aged children. If this is spent outdoors, all the better for their visual development.
Contact us to arrange a myopia assessment and comprehensive general eye & vision check.
For additional information about myopia, its causes and treatments available please visit our Myopia Clinic website.
Links:
“The Case for Myopia Control Now” – an article by a US professor of ophthalmology (eye surgeon) urging action to slow down myopia.
Go to this comprehensive external website www.myopiaprevention.org for some further interesting reading on the topic of myopia prevention, and links to actual scientific research articles.
