To determine the longitudinal changes of age and refraction in predicting myopia progression with risk under the coronavirus disease 2019 (COVID-19) pandemic in a 3-year follow-up of a Chinese cohort.

This was part of the large-scale Tianjin Eye Study, a population-based cohort study that longitudinally investigates the relationship between the age, refraction, and development of childhood RE in Tianjin, China.

Inclusion Criteria:

• no concurrent eye disease;
• age 6-15 years.

Exclusion Criteria:

• significant systemic illnesses
• ocular conditions that could affect the corneal curvature, including congenital corneal diseases,
• pterygium, keratoconus, other corneal degeneration or dystrophy conditions,
• media opacity, uveitis, glaucoma
• a history of intraocular surgery, refractive surgery,
• neurologic or retinal diseases, current corneal refractive therapy (ortho-K),
• low-dose atropine therapy for myopia control

This study includes 34,400 schoolchildren, with a 36-month follow-up from 2019 to 2021. In addition to RE considerations, the inclusion criteria were: no concurrent eye disease; age 6-15 years. The exclusion criteria were: significant systemic illnesses or ocular conditions that could affect the corneal curvature, including congenital corneal diseases, pterygium, keratoconus, other corneal degeneration or dystrophy conditions, media opacity, uveitis, glaucoma or a history of intraocular surgery, refractive surgery, neurologic or retinal diseases, current corneal refractive therapy (ortho-K), or low-dose atropine therapy for myopia control. The ethics board of the Tianjin Eye Hospital, Tianjin, China, approved this school-based cohort study (No: 2022018).