Myopia continues to progress in more than 1/3 of young adults, but at lower rates than during childhood, according to a study published in JAMA Ophthalmology.
Researchers analyzed the medical history of a cohort of 516 participants without myopia at baseline and 698 participants with high myopia at baseline, and performed eye exams in 20 and 28 year follow-up assessments. The exams included conjunctival ultraviolet autofluorescence (CUVAF) photography, ocular biometry, post-mydriatic autorefraction, keratometry, and lens thickness measurement. Myopia and high myopia were defined as having a spherical equivalent ≤0.50 D or ≤6.00 D, respectively, in 1 or both eyes.
Individuals with orthokeratology lenses, history of cataract or corneal surgery, or keratoconus were excluded from the study. However, participants who underwent laser refractive surgery in the 8-year period were included if they provided estimated presurgical refraction data.
A total of 14% of participants (n=72, 50.6% men) who did not have myopia at baseline developed it by the conclusion of the study. Univariable logistic regression revealed smaller CUVAF areas, parental myopia, and education ending at secondary school were associated with myopia incidence. Education, however, lost significance in a multivariable analysis.
Of the 683 individuals (338 men, 5 with prior laser refractive surgery) included in the high myopia incidence analysis, 5 progressed to high myopia (0.7%) and tended to have myopia ≤-5.00 D at baseline with a progression of <2.00 D.
Researchers found that nearly 2/5 of participants experienced a 0.50 D shift or greater in at least 1 eye over the 8 year duration. Axial length change was greatest among individuals with myopia shift. Spherical equivalent, axial length, and lens thickness showed significant changes after correcting for sex, race, and other known risk factors for myopia in the multivariate analysis.
Investigators noted that women are more likely to experience spherical equivalent decrease and axial elongation than men. East Asian individuals had slightly higher rates of axial elongation and corneal flattening compared with White individuals (0.014 mm vs 0.008 mm). Parental myopia was also linked with quicker spherical equivalent decrease.
“The eye continues to elongate axially in some participants during young adulthood, which may contribute to the increased risk of myopia-related complications as these young adults reach middle and older age,” according to the researchers. “Our findings highlight the need for research into myopia control methods in young adults in addition to those currently being researched in children.”
Study limitations include reliance on self-reporting for some participant data and poor follow up retention.
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Lee S S-Y, Lingham G, Sanfilippo PG, et al. Incidence and progression of myopia in early adulthood. JAMA Ophthalmol. Published online January 6, 2022. doi:10.1001/jamaophthalmol.2021.5067