A 12-year study has shown early onset myopia is strongly associated with high myopia risk in adulthood and delaying onset substantially reduces the risks, supporting the need for prompt myopia prevention strategies.
While early-onset myopia is well known to progress to high myopia in adulthood, prior to this study there was no accurate estimation of what specific age for myopia onset was associated with the probability of developing high myopia in adulthood. To counter this, researchers from the Sun Yat-sen University of Medical Sciences in Guangzhou, China, launched a prospective long-term cohort study of Guangzhou twins (2006-2018), enrolling 443 participants who developed myopia. Study participants were then followed up annually until they were at least 17-years-old.
The study’s 12-year findings confirmed the risk of developing high myopia was greater than 50% (14 of 26) for those with myopia onset at seven or eight years of age. The risk substantially decreased to approximately 30% (12 of 37) for onset at nine years of age; 20% (14 of 72) for onset at 10; 14% (11 of 78) for onset at 11; and less than 2% (3 of 230) for onset at 12 years or older.
Among the 443 eligible participants 247 [55.8%] were female; the mean [SD] age at myopia onset was 11.7 years; and 54 (12.2%) developed high myopia (spherical equivalent −6.00 diopters or worse determined by cycloplegic refractions) in adulthood.
The study was published in Jama Ophthalmology.