Early-onset myopia tends to progress to high myopia in adulthood, but until recently, there’s been little long-term data on the risk of developing myopia later in life associated with a specific age at onset.

Researchers in China evaluated a cohort of 443 individuals with myopia over 12 years and for 365 of the participants, they determined the age of myopia onset by questionnaire and prospective annual cycloplegic refractions.

Among the 443 participants (247 female), the mean age of myopia onset was 11.7±2 years, and 54 (12.2%) developed high myopia in adulthood.

According to their findings, the risk of developing high myopia in adulthood decreases significantly the longer myopia onset is delayed (Table 1).

“Each year of delay in the age of onset substantially reduces the chance of developing high myopia in adulthood, highlighting the importance of identifying effective prevention strategies,” the researchers concluded. Increasing outdoor time is just one effective prevention strategy for myopia onset in school-aged children, they added.

Table 1. High Myopia Development

 Age at onset% developed in adulthood
Seven to eight years53.9%
Nine years32.4%
10 years 19.4%
11 years 14.1%
 12 years 1.3%

Hu Y, Ding X, Guo X, et al. Association of age at myopia onset with risk of high myopia in adulthood in a 12-year follow-up of a Chinese cohort. JAMA Ophthalmology. September 17, 2020. [Epub ahead of print].