Myopia prevalence in Canadian school children: a pilot study

Area of Science:

• Ophthalmology
• Pediatric Optometry
• Public Health

Background:

• Myopia, or nearsightedness, is a growing global health concern, particularly among children.
• Understanding the prevalence and contributing factors of myopia in diverse populations is crucial for developing effective interventions.

Purpose of the Study:

• To determine the prevalence of myopia in children aged 6-13 in a Canadian suburban region.
• To assess the proportion of uncorrected myopia within this population.
• To investigate potential environmental factors, such as outdoor activity, associated with myopia.

Main Methods:

• A pilot study involving 166 children aged 6-8 and 11-13.
• Refraction with cycloplegia and ocular biometry (axial length) were performed.
• Myopia defined as spherical equivalent refraction (SER) ≤-0.50 D.
• Parents completed questionnaires on children's daily activities, including outdoor time.

Main Results:

• Overall myopia prevalence was 17.5%, with significantly higher rates in older children (28.9% in 11-13 year olds vs. 6.0% in 6-8 year olds).
• Axial length increased significantly with age (p < 0.01).
• Each additional hour of outdoor time per week was associated with a 14.3% reduction in the odds of myopia (p = 0.007).

Conclusions:

• Myopia prevalence escalates sharply during childhood, from 6% in younger children to 29% in older children.
• A substantial proportion (35%) of myopic children in this cohort remained uncorrected.
• Increased time spent outdoors appears to be a protective factor against myopia development in children.