Atropine eye-drops for preventing myopia progression
Why should we try to reduce myopia progression in our children?
Myopia is not only a cosmetic condition, it is an eye disease.
The main aim of controlling myopia progression is to prevent the complications of high myopia later on in life. Adults with high myopia are 10-20 times more likely to develop retinal tears, retinal detachments, macular degeneration, premature cataracts, and glaucoma. These are conditions that can cause severe loss of vision and blindness. LASIK can cure high myopia but your eye is still more susceptible to these conditions after LASIK.
A secondary aim is keep the degree of myopia as low as possible so as to achieve some degree of spectacle/contact lens independence: eg being able to play soccer or go jogging; enjoy water sports such as swimming, snorkeling, scuba diving; or attend a social function without spectacles.
Who is at risk of myopia in Singapore?
5-10% of 5-6 years old kindergarten children
10-20% of 6-7 years old primary 1 children
50% of 9 year old primary 3 children
66% of 12 year old primary 6 children
80% of 18 years old NS men
Myopia is increasing in both frequency and severity and starting younger in Singaporean children. It is unusual for our young in Singapore to have perfect eye-sight without glasses.
What is causing the myopia epidemic?
There are both genetic and environmental factors. The Chinese and the Japanese have more myopia predisposing genes than the Malays, Indians and the Caucasians. However, myopia has increased for all the races resident in Singapore. This generation of children has much more myopia than their grand-parents. As the gene pool only changes significantly over hundreds of generations, it is the changes in the visual environment that is causing the rapid rise in myopia rates.
The change is that our children spend too much time looking near and not enough time looking into the distance. This is caused by urbanization with the move from kampong to flats. Our children are spending too much time indoors either in school or at home. They are not spending enough time outdoors. It is caused by the Age of Information with much more reading needed and much more exciting books available. It is the increasing amount of school work, home work and enrichment classes our children experience at an earlier age in their life. Too much time is spent on near vision activities like computers, gameboys, books, television etc and not enough time on far vision activities like exploring the neighbourhood, kicking a ball, hitting a shuttlecock, cycling, skating, swimming or just watching the world go by.
Can we recreate the childhood of the past with many hours of outdoor time each day? It is difficult with both parents working, with the loss of the extended family living in a one house, the intense rat race which starts for our children in primary school, and the availability of a large variety of exciting books, television programmes, and computer games. It is difficult to achieve enough outdoor time.
We have to complement it with eye-drops.
Who should use atropine eye-drops?
Any child with
- progressive myopia
- rapidly progressive myopia.
- strong parental & family history of high myopia
- moderate to high myopia and still progressing
- very low myopia whose parents want to reduce spectacle wear / dependence
- parents unable to bring child outdoors or curb excessive reading & computer gaming
- family history of vision loss from complications of high myopia
How effective is atropine and other treatments?
Atropine is the most effective treatment for the prevention of myopia progression in children. With atropine 1%, 50% of patients will stop progressing completely after starting atropine eye-drops. It’s effectiveness has been proven by more than 13-14 large clinical trials which have been published in major international ophthalmology journals and abstracts of these are readily available online.
Atropine is much more effective than wearing hard contact lenses or progressive/ bifocal spectacles. Clinical trials have also been done for these treatments but there have been mixed results for rigid contact lenses. Most trials show progressive/ bifocal spectacles do not prevent myopia progression.
There is little evidence to support the use of the following for myopia control: acupressure massage, Janet Goodrich exercises, pinhole glasses, Neurovision, Bates method and Eye Relax machines.
Orthokeratology or CRT (corneal refractive therapy) seems to be mildly effective with a saving of -0.25D/year (Hiraoka 2012) to -0.40D/year (Cho 2012).
How safe is atropine?
Atropine eyedrops has been discussed for myopia treatment since the 1930s and the first clinical trials on children was done in 1971. Since then there has been more than a dozen large trials of a few hundred children each. Since 1971 or the last 35 years, there has been no case report of any permanent or serious adverse reaction to long term instillation of atropine eyedrops. There has been no case report of cataracts or macular degeneration caused by atropine eye-drops. There is a theoretical risk of premature cataracts from increased sunlight entering the eye through a dilated pupil. Laboratory mice exposed to high UV light develop cataracts earlier. This risk should be guarded against with photochromatic spectacles and sunglasses etc. As for age related macular degeneration, it has not been proven to be due to sunlight exposure.
Whether there will be delayed side-effects appearing after 35 years is unknown. But then the same is true for a lot of long term drugs that are being prescribed eg: medicine for hypertension, high cholesterol, diabetes, heart disease, pain-killers etc.
The eye-drop has been tested in a large trial in Singapore from 1998-2003 with excellent results and there is still a new ongoing trial now to determine the ideal dose of atropine. The safety committee of this local trial did not find any reports of serious adverse reactions to atropine eye-drops in their search.
Atropine eyedrops have been used for the long term treatment of cataracts, lazy eye, and inflammation of the eye without serious side effects. Atropine has been taken orally for decades as treatment for diarrhea, colic, gastritis and irritable bowel syndrome.
You may avoid atropine because of the theoretical risks due to increased exposure to sunlight and UV radiation but you cannot escape the known and real risks of eye complications from high myopia if we do not use atropine. For me, after 35 years of atropine research without complications, it is safer to use atropine than to be highly myopic.
Despite the above, there are 2 schools of thought here and there are ophthalmologists who feel that myopia is not a dangerous condition and that the risks of very long term side-effects outweigh the risks of atropine treatment. I have never met an ophthalmologist who could convince me that atropine treatment of progressive myopia is not a safe standard of care.
What are the side effects and how to treat them?
These side effects are temporary and will disappear sometime after stopping the eye-drops.
Photophobia (discomfort with bright lights)
Atropine eye-drops dilate the pupils. This lets in more light into the eyeball. The pupils are unable to constrict to block out the sunlight and your child may be uncomfortable in bright sunlight. There is usually no problem indoors. Your child may get used to it after a while.
Management of the side-effect Photophobia
1. Photochromatic lenses (eg Transition lenses), clip-on sunglasses, prescription sunglasses, caps, hats, sun-visors, sunshields. A standard letter can be given upon request to the teacher allowing sunglasses in school.
2. Omitting the eyedrops before long periods of intense sun exposure eg going to the beach or park for a picnic or going to a beach resort for a sunny holiday.
3. Varying the time of instillation of the eye-drops eg. After coming home from the beach
4. Reducing the dosage of the atropine eye-drops.
Photochromatic lens: Outdoor
Photochromatic lens: Indoor
Presbyopia (inability to read and focus near)
Atropine weakens the focusing muscle of the eye that helps the child to read and focus near. This effect will wear off completely sometime after the atropine is stopped.
Management of the side-effect Presbyopia
- Nothing. The child can often still read well. Sometimes they get tired easily and this encourages them to take frequent breaks from reading. It may decrease the total amount of near work which is not a bad thing for myopia control.
- Take off the glasses to read. If the myopia is less than -4.00 D, the child can read well just by taking off the glasses.
- Progressives or bifocals. Progressives are more cosmetically acceptable which is a strong point for children. They have a narrower field of clear vision which is not good as children are physically more active and mobile than adults. However, the intermediate vision is useful for desktop computers. Bifocals have a line across or an obvious lens button which may draw the attention of other children. However they have a broader field of vision. The near vision is better than with progressives. Children usually prefer progressives.
- Undercorrect the spectacles slightly. However, undercorrection has been reported to increase the myopia progression rate.
- Reducing the dosage of the atropine eye drops
Other common side-effects
Allergy with itchiness, red eye and a lower eyelid rash after instilling the eye-drops. The allergy may be to the preservative. The solution is to change to preservative free eye-drops. The preservative is usually benzylkonium chloride. If the allergy is to atropine, then we can change to another drug eg. homatropine.
Systemic side effects such as flushed face, fever, rapid heart rate, dry mouth and skin, constipation, drowsiness, occurs mostly in infants and toddlers. Such young children rarely have myopia. Glaucoma is not a side effect of atropine treatment for myopic children.
Keep the eye-drop in a safe place as a toddler accidentally may drink it and this will be very toxic.
How do I use atropine eye-drops?
Atropine eye-drop comes in various concentrations and is instilled at different frequencies depending on the response of the child. The aim is to strike a balance between a higher dose causing uncomfortable side effects and a lower dose that does not control the myopia adequately. The optimal dose varies from child to child and your ophthalmologist will tailor the dose to get good myopia control with minimum side effects. The dose available ranges from atropine 0.01% to 1%.
I usually start with a moderate dose and taper up and down depending on the side effects and the effectiveness of the myopia control. For very young children 4-5 years, I prefer to start with a low dose and for patients with very rapid progression, I prefer to start with a moderate to higher dose.
The eye-drops will be instilled for at least 2-3 years after which there will be a review to see if the need to prevent myopia progression remains.
At this dose, there is almost no noticeable side effect. The child does not complain about presbyopia (lao hua) nor photosensitivity. When examined closely, the pupil may still be slightly dilated. All effects disappear after a day. No photochromatic nor progressive glasses are needed. The trouble with this low dose is that in about half the children, the myopia continues to increase rapidly and the slowing effect is not as strong in the others.
This is a mild concentration and instilled once nightly between dinner and bedtime. The myopia control is not as good as stronger concentrations. It is useful for children with very low myopia as the focusing for near is not affected much. Progressive glasses are not needed usually but photochromatic glasses or sunglasses are still advisable. Children with low (eg.0.50 to 1.00D) myopia may need reading glasses if stronger doses are used. It is not so effective if the myopic progression is very rapid. Another advantage is the rapid recovery and reversal. The side effects disappear about 24 hours after stopping.
How do I use atropine 0.3% – 0.5%?
This is an intermediate concentration and is usually used every night after dinner to before bedtime. Some children on this regime do not need progressive glasses. Photochromatic lenses are recommended. Sometimes the eyedrop can be used every other night. The side-effects remain for a few days after the eye-drop is stopped so if going for a sunny holiday, the eye-drops should be stopped a few days before and resumed after coming back. A ski-ing holiday is also a sunny holiday. The eye-drops can be omitted once or twice a week on the night before PE or an outdoor excursion without much compromise on the myopia control.
How do I use atropine 1%?
This is the highest concentration and is usually used every night at dinner or bedtime. Most children on this regime will need either photochromatic or progressive spectacles or both. This concentration is useful for children who have failed atropine 0.5%. I seldom use it as first line treatment because of the side-effects.
For children who are uncooperative with the instillation of eye-drops, or who have sensitive allergic eyes; or where the parents are too busy to instill the eye-drops, atropine 1% can be instilled only once a week with good effect. Atropine 1% is no longer available in Singapore in tiny disposable preservative-free vials for children with allergies or sensitive eyes.
The eye-drops can be omitted now and then before periods of prolonged outdoor sunny activities. Before going for a sunny outdoor holiday, the eyedrops can be stopped up to one week before leaving the country.
How do I use homatropine 2% ?
This is a mild to moderate strength dose. It is stronger than atropine 0.125% but maybe slightly weaker than 0.3%. Nowadays, I only use this when the child is allergic to atropine.
This is mild to moderate and is usually used once every morning. The myopia control is less but the side-effects are tolerable. Most children can still read without bifocals and the photophobia is mild. The eye-drop lasts only about a day so the next day the side-effects have almost worn off. So if there is outdoor physical exercise (PE) the next morning, the eye-drops can be instilled in the afternoon after the PE. Or if there is PE the next afternoon, then the eyedrops can be instilled the night before the PE instead of the morning of the PE.
If the morning dose cannot be tolerated because of side-effects, the child can use progressives or photochromatic glasses. If this is not acceptable, then a night dose before bedtime is very well tolerated. The night dose is not as effective in myopia control. This is a strong disadvantage because if both parents are working, it is quite a rush in the morning to get the drops in.
Myopia is a potentially sight-threatening disease that will affect most of our Singaporean children. It can be prevented or reduced by spending more time outdoors and less time indoors. As we cannot get our children outdoors enough, it is often helpful to instill atropine eye-drops. The eye-drops are well researched and are safe and effective.
ADVICE ON MYOPIA PREVENTION & CONTROL
INCREASE OUTDOOR ACTIVITIES
- Spend more time outdoors and looking into the distance.
- Encourage outdoor hobbies like sports, cycling, jogging, fishing, swimming, tennis, basketball, photography, bird-watching etc.
- 14 hours of outdoor per week, average 2 hours per day.
- Outdoor activities protect against myopia in children who read a lot.
INCREASE DAYLIGHT EXPOSURE
- Lots of light exposure reduce myopia.
- Outdoor sports better than indoor sports.
- Read next to window, a balcony, or a patio.
- Increase home lighting.
- Do not draw curtains.
REDUCE NEAR WORK (NOT AS IMPORTANT AS INCREASING OUTDOOR TIME)
- Reduce the total time spent on near work such as reading & computer work/ games.
- The nearer the work, the more myopia it causes, eg TV is better than hand-held computer games.
- Connect your computer to your TV and work as far as possible.
- Atropine eyedrops are safe and effective in slowing or preventing the progression of myopia.
- Other methods eg. acupuncture, Eye-Relax, contact lenses, bifocal/ progressive spectacles, vitamins, Bates’ method etc are probably not effective or have only a very weak effect. Orthokeratology (corneal refractive therapy) has some evidence to support its efficacy but the effect is small and there is a known risk of infection which can scar the cornea (1in 500 to 1000).