Everything About Childhood Myopia.
PREVALENCE OF MYOPIA IN SINGAPORE
Myopia is the top visual impairment among Singaporeans. Roughly 28% of Primary 1 and about 65% of Primary 6 students are diagnosed with myopia. However, the percentage had remained stable for the past decade. There are more children now with myopia than there was in the past, as children compete in a highly educated society, with many investing most of their time in making education their top priority, along with the increased availability of electronic devices and smartphones.
SO WHAT IS MYOPIA? (short-sightedness)
Myopia is a condition of an elongated eyeball, causing distant objects to be incorrectly focused in front of the retina, thereby resulting in blurred vision. Myopia progresses as the eyeball grows and can occur as infant as juvenile years. There’s a need for early detection and treatment.
High degree of myopia comes with the risk of a higher probability of early-onset cataract, glaucoma and retinal detachment in adulthood, which may give rise to severe damage and possibly leading to total loss of vision.
- Genetics. Children with parental history of myopia were found to be more likely to develop myopia. Studies have revealed that 18.2% in children with one myopic parent and 32.9% in children whose both parents are myopic, are prone to develop myopia early. (Mutti DO et al., 2002)
- Environmental factors also play a role, as in 2008, researchers assessed the relationship of indoor and outdoor activities with the prevalence of myopia in children and the assessment revealed that higher levels of outdoor activities with UV exposure correlates to lower myopia prevalence. (Kathryn A.Rose et.al, 2008)
Notice your child squinting? Are they sitting too close to the television? Blinking excessively? Eye-strains or rubbing their eyes incessantly? Do be on the lookout as they may be developing myopia and it is essential to detect and correct it early.
TREATMENT & PREVENTION
Currently in Singapore, Atropine and Myopine eyedrops are widely used across most hospitals and eye-care centres. These eye drops relaxes the pupillary muscles and prevents over-contraction of these muscles, thereby preventing further increase and give stability to Myopia. These drugs come in 3 dosages: 0.01%, 0.125% and 1.0%. There are usually very few mild side effects, especially with the lower dosages. Possible mild side effects include light sensitivity and reading difficulties. These minimal side effects are generally safe and tolerable for children. The eyedrops have shown to be effective and safe in retarding myopia by 50-60% (Chia.A, Lu. Q, Tan D, 2016). Recent studies by the Singapore Eye Research Institute (SERI) revealed that myopia control is still favourable even with a lower dose of Atropine, with minimal side effects. (Chia.A, Lu. Q, Tan D, 2016)
Another option towards controlling myopia is the Orthokeratology lenses. (Ortho-K). It is an overnight hard contact lens that will temporarily reshape the cornea. Specially designed to be worn while sleeping and removed upon awaking daily, it allows good day vision without the need of glasses or contact lenses for about 12-48 hours. Unlike LASIK, it is not a permanent vision correction. When the Ortho-K is left out for a few nights, myopia will return. Although Ortho-K lenses allow oxygen to get to the cornea, as with any other contact lenses, it carries risks and complications. Children have been reported with severe corneal infections or ulcerations. Therefore it may come with a cost of corneal scarring or some degree of vision loss. It is vital that Ortho-K users understand the proper hygienic care of the Ortho-K lenses.
Adopting good eye care habits can help in preventing myopia or its progression.
- Engage in sports and other outdoor activities regularly.
- Visual breaks of 10 mins after every hour of near work (try to look at distant objects).
- An ideal reading distance of 35-40cm and an ideal computer monitor viewing distance of 50cm, with adequate ambient brightness.
By taking active steps in preventing and controlling your child’s myopia, you can delay the onset and reduce its progression significantly.
ATROPINE AND MYOPINE.
1. Does wearing glasses delay the myopia progression?
Glasses may provide better vision and ensure your child functions better in his/her environment. It is vital that your child puts his/her glasses on all the time as complications like Amblyopia (“lazy eye”) or Strabismus (“misaligned eye”) may occur if the weaker eye is uncorrected for better vision. A child’s visual system is developing, especially during the first 7 years of life, thus glasses may help to ensure normal visual development.
2. How do I determine which method of myopia control is best suited for my child?
It depends on your child’s lifestyle and compliance, as well as the Ophthalmologist’s advice and evaluation. Presently, Atropine eyedrops are commonly used throughout Asia. These eyedrops relax the pupillary muscles thereby preventing increase in myopia. It normally offers minimal side effects with effective control. It is important that the child complies with the treatment regimen on a long-term basis. It does take some motivation on the part of the parents and the child to instill the drops on a daily basis, which is one drop at night to each eye before going to bed. The medication does not cause stinging when applied.
3. Why does my child’s myopia progresses rapidly every year?
Myopia develops when the length of the eyeball (front to back) becomes longer so when incoming light rays enter the eye, it is focused in front of the retina (light sensitive layer of tissue) instead of being focused on the retina itself, causing blurry vision. Unfortunately, myopia cannot be reversed or corrected naturally. Only controlling and stabilising it can prevent your child from further increasing his/her myopia. Myopia will stabilise by the age of 18 or when their body stops growing. Before that, it is essential to monitor your child’s myopia with regular eye checkups every 6 months and comply to the treatment regimen.
4. Does the myopia control methods reduce my child’s myopia?
Currently, there are no methods to cure myopia as there is no control on the growth of the eyes. These available myopia control methods aim to stabilise or slow down myopia progression only. Once the person reached 18 years of age, he or she may choose to have a permanent correction with Laser Refractive Surgery (eg. LASIK) to treat their myopia and enjoy freedom from spectacles/contact lens. Laser Refractive Surgery normally enables spectacle/contact lens freedom till to the time one develops cataracts due to old age.
5. Do eye exercises or vitamins treat myopia?
Advertisements or health shows may claim that it can cure myopia but sadly, it is a myth. There is no clinical evidence to support the benefits to the eyes in taking vitamins or by doing eye exercises. Eye exercises may only help for better focus and in reducing eye-strains. On the other hand, adopting good eye-care habits may prevent myopia or slow down its progression. The only definitive treatment for myopia would be glasses, contact lenses, LASIK surgery or advanced Refractive Cataract Surgery & Intraocular Lens Implantation. The latter 2 surgeries are only performed in adulthood – LASIK surgery is FDA approved for 18 year olds and Cataract Surgery is typically performed from middle age onwards.
6. What are the consequences of myopia?
Myopia carries many long-term sight-threatening complications as myopes are more likely to develop retinal detachment, macular degeneration, early onset of cataracts and glaucoma. The higher the myopia, the higher risk of developing these conditions, and at an earlier age.
References and credits:
Audrey Chia et al (2012) Atropine for the Treatment of Childhood Myopia: Safety and Efficacy of 0.5%, 0.1%, and 0.01% Doses (Atropine for the Treatment of Myopia 2)
Kathryn A. Rose et al (2008) Outdoor Activity Reduces the Prevalence of Myopia in Children
Mutti DO, Mitchell GL, Moeschberger ML, Jones LA, Zadnik K
Invest Ophthalmol Vis Sci. 2002 Dec; 43(12):3633-40.
Five-year clinical trial on atropine for the treatment of myopia 2: Myopia control with atropine 0.01% eyedrops. Ophthalmology 2016 Feb;123(2):391-9.
Authored by: Dr Natasha Lim