Myopia is increasing in New Zealand. The following article discusses treatment options aimed at prevention.
The following information on the treatment and prevention of myopia is a great guide developed by respected New Zealand eye surgeon Malcolm McKellar. http://drmalcolmmckellar.co.nz
What is Myopia?
Myopia, or short-sightedness, is a condition where only close objects can be seen clearly. It occurs when light entering the eye comes to a focus in front of the retina instead of directly on it. People who have myopia need glasses or contact lenses, or have corrective laser surgery in order to see distant objects well. In New Zealand, 30% of adults have myopia and it is more common in children, particularly Asian children.
Why is Myopia a problem?
Glasses, contact lenses, laser refractive surgery and regular eye examinations are costly. Myopic children and adults may not engage actively in sports as those with normal vision. Those who are very short-sighted are also at greater risk of glaucoma and retinal detachment.
Can Myopia be prevented?
For many years optometrists and ophthalmologists have been trying to prevent myopia. They have studied the use of standard glasses and contact lenses, bifocals and progressives, exercise, diet and many types of eye drops. All of these have had either no effect or a very mild effect.
Although myopia can not be prevented, there are three treatments that have been shown to significantly limit its development.
Atropine eye drops, which are used to treat other eye problems, slow the progression of myopia. However, how they work is unknown and most children find the side effects of standard doses unacceptable. Recent research has shown that much lower concentrations can reduce the rate of myopia progression without side effects in most cases. Low dose atropine is now widely used to prevent myopia. It’s not commercially available but can be “compounded” by special pharmacies.
With orthokeratology, or OK, specially-designed rigid contact lenses are worn overnight to mould the shape of the cornea, the clear window at the front of the eye. The moulding changes the way light is focused onto the retina. When the lenses are removed each morning children have good vision. More importantly, with orthokeratology, the altered focus of peripheral light seems to stop myopia progressing.
Time outdoors is associated with reduced myopia progression. It is not clear how this works, but it may be that ultraviolet light causes changes in the wall of the eye. Just one to two hours of outdoor time per day appears to be required. This is relatively easy for children who walk, bike or scooter to school and who are outside during playtime.
Myopia prevention and your child
Myopia prevention is best discussed with your ophthalmologist and optometrist. Ophthalmologists can examine the eye, including measuring the optical components and determine whether it is likely to respond to anti-myopia treatment. They are also involved in prescribing atropine eye drops. Optometrists who specialise in orthokeratology will fit and monitor contact lens wear.
Can all Myopia be prevented?
At present only progressive myopia due to increasing eye length is treated.
How long will treatment take?
Treatment will need to continue until the chance of myopia progression has ceased. Most children will need treatment until they stop growing.
Contact lens wear and atropine treatment can have potential side effects. These are rare but need to be considered. It is not yet known what will happen when preventative treatment stops, and myopia may still develop later in life. Nevertheless, due to the problems associated with myopia, most ophthalmologists and optometrists recommend treatment.
This information does not cover all that is known about myopia prevention. Please discuss further with your optometrist or ophthalmologist.