The rising rates of myopia worldwide are prompting researchers and clinicians to find ways to halt its onset and progression. A new study presented at ARVO’s virtual meeting suggests gender may play a role in (or at least be correlated with) the development of this condition, which was found to be more common in younger girls of the present generation yet, in adults, had a greater prevalence among males.

The research team from the Netherlands and Poland explored gender differences in myopia development based on two prospective, population-based cohorts from different generations. The first investigation, Generation R, enrolled roughly 7,000 participants and tracked them from fetal life until young adulthood. The second, the Rotterdam Study I-III, included about 9,000 participants who were older than 45.

Cycloplegic refraction was measured in the children at ages six, nine and 13, while automated refraction was evaluated in the adults and axial length and height were calculated in both groups. Myopia was defined as a spherical equivalent less than -0.5D in at least one eye. Children responded to questionnaires about their lifestyle including near work and outdoor exposure, and adults were additionally queried about their education levels. Change in height was also taken into account.

In children, the rate of myopia steadily increased from 2.5% to 11.5% and then nearly doubled to 22.5% at age six, nine and 13, respectively. The prevalence was higher in adults at roughly 31%.

Female gender was linked to childhood myopia, but this finding was the opposite in adults. Whether a child developed myopia or not appeared to be influenced by several factors including outdoor exposure, height growth, sport participation, reading time and the number of books read per month. These factors collectively lessened the gender effect by roughly 35%. In adults, education was the most important mediator and lessened gender’s influence by about 90%.

These findings provide compelling evidence that lifestyle factors and education are strong drivers of myopia and that girls, in particular, should be guided to adhere to protective behavior to lessen their myopia risk, the researchers said.