Posts tagged ‘myopia’

December 12, 2012

How to slow down myopia (nearsightedness)

by Vancouver Eyecare Professionals at Avenue Eyecare

Parents are often worried about their children’s nearsightedness (myopia) progression.  Nowadays, approximately 40% of children will develop myopia compared to 25% during the 1980′s.

There are 3 different types of myopia

1. Pathological myopia – Occurs early in life with little progression (Congenital)
2. School myopia – Begins between ages 8-12 and progresses dramatically
3. Adult-onset myopia begins at age 18 or older

Genes vs. environment

Studies have shown that myopia has strong genetic and environmental components.

1. Genetics – Studies have shown that a child with parents without myopia has a 10% chance of developing myopia.  With one parent, it’s 25% and with two parents, it’s 35%.
2. Environment – In school settings, progression of myopia was increased by 50%.  Lack of outside sunlight exposure is a strong risk factor for development of myopia

Progression and treatment

1. Bifocal and progressive addition lenses
According to the COMET study, children that wore single vision had a mean progression of -1.48D in 3 years compared to the progressive group of -1.28D.  Even though it’s statistically significant, clinically, it’s not.  This means that wearing bifocals or progressives may not help prevent further myopia.

2. Undercorrection
Sometimes parents may to have a lower prescription for their children because they feel they might be dependent on their glasses.  But research shows that undercorrection may increase myopia progression.

3. Orthokeratology
This type of lenses have show a 30%-50% reduction in the progression of myopia.

4. Vision therapy
Vision therapy, also know as vision training, is used to improve vision skills such as eye movement control, eye focusing and coordination and the team work of the two eyes.  There is no long-term study available to show that vision therapy can slow down the progression of myopia.

5. Atropine
Studies have shown that 1% atropine can slow the progression of myopia by almost 95%.  Atropine knocks out the focusing ability of the child and somehow blocks the signal that results in the elongation of the eye.  However, atropine does have side effects which include loss of accomodation (focusing) and photophobia (sensitivity to light).  Recently, studies have shown that 0.025% or 0.01% used once daily is just as effective as 0.5% atropine.  However, atropine treatment is not used on a regular basis in Canada.

If you are concerned about your child’s progression of myopia, bring your child in for an annual comprehensive eye exam at Avenue Eyecare.

drtung@avenueeyecare.com
Vancouver Kerrisdale Optometrist

Contact Avenue Eyecare to book your appointment today.

July 6, 2011

Control Nearsightedness with Outdoor Activities

by Vancouver Eyecare Professionals at Avenue Eyecare

It’s July, the sun is shining, the beaches in Vancouver are bustling with people in bathing suits, and kids are out of school.  Summer is in full swing!

I had a patient come in the other day who was asking about ways to control or decrease the progression of her child’s nearsightedness.  We know that it is caused by a combination of genetics and environmental factors.  The usual theories include decreasing excessive near work, corneal reshaping (orthokeratology), and rigid gas permeable lenses.

I want to highlight a more recent study from the University of Sydney in Australia, led by Dr. Kathryn Rose, that links high rates of outdoor activity to lower rates of nearsightedness.  The study included 2367 Australian school children who underwent eye exams and completed questionnaires about their daily activities.  The interesting finding was that the lowest rates of nearsightedness were associated with the highest rates of outdoor activity, regardless of how much reading and other near work they did.  The researchers believe that the reason is related to the light intensity children are exposed to while outdoors.  The study also found that children need 10-14 hours per week outside, in addition to their outdoor breaks during school.  I hope this gives parents a good reasons to get their children out of the house and playing outside this summer!

To read the full study:
http://synapse.princeton.edu/~sam/outdoor_activity_myopia_Rose.pdf

Rose, K A, Morgan, I, Ip, J, Kifley, A, Huynh, S, Smith, W, Mitchell, R P 2008, Outdoor activity reduces the prevalence of myopia in children, Ophthalmology: journal of the American Academy of Ophthalmology, 115(8), 1279-1285

Dr. Jessica Chang, OD  drchang@avenueeyecare.com

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