Prevalence of myopia in Danish conscripts.

Area of Science:

• Ophthalmology
• Public Health
• Epidemiology

Background:

• Myopia prevalence has varied historically in Denmark.
• Understanding current myopia trends and associated factors is crucial for public health interventions.

Purpose of the Study:

• To determine the prevalence of myopia in Danish male conscripts in 2004.
• To compare current myopia rates with historical Danish studies from 1882 and 1964.
• To analyze the relationship between myopia and educational level, ethnicity, intelligence (IQ), body mass index (BMI), and height.

Main Methods:

• A cross-sectional study of 4681 male conscripts was conducted.
• Data collected included age, place of birth, anthropometrics (weight, height), refractive error, visual acuity, years of education, occupation, IQ score, and ethnicity.
• Refractive error was assessed using spectacle or contact lens power, with myopia defined as <= -0.5 D spherical equivalent.

Main Results:

• The prevalence of myopia was 12.8%, with high myopia (< -6.5 D) at 0.3%.
• Myopic individuals demonstrated higher IQ scores (45.3 vs. 41.4, p < 0.001) and attained higher educational levels compared to emmetropes.
• No significant associations were found between myopia and BMI, height, or ethnicity.

Conclusions:

• Myopia prevalence in Danish conscripts has decreased since 1964, while remaining stable compared to 1882.
• High myopia prevalence has significantly decreased since 1882 and shown a declining trend since 1964.
• Higher educational attainment and IQ scores are associated with myopia in this cohort.