Prevalence of myopia and myopia trends among optometric telemedicine users in Spain: a retrospective nationwide observational study.

PURPOSE: To evaluate the prevalence, severity, and temporal trends of myopia among patients attending optometric telemedicine screenings across Spain, and to describe age-specific distributions over time. METHODS: This retrospective, observational study analysed refractive data from 500,432 eyes of 269,868 patients evaluated at optometric centres nationwide in Spain within the UpRetina network between 2016 and 2024. Spherical equivalent (SE) values classified eyes into mild (SE ≤ - 0.50 D to - 3.00 D), moderate (-3.00 D to - 6.00 D), and high myopia (SE ≤ - 6.00 D). Both eyes were included when valid refractive data were available. Temporal trends were assessed by year and age. Descriptive and inferential statistics determined prevalence, SE distributions, and temporal changes. RESULTS: Among 500,432 eyes analysed, 104,497 (20.9%) were myopic. Of these, 60.1% were mild, 30.3% moderate, and 14.1% high myopia. Mean SE values were - 1.57 D (SD 0.68) for mild, - 4.18 D (SD 0.84) for moderate, and - 8.58 D (SD 2.92) for high myopia. High myopia was most prevalent in adults aged 20-40 years (16.2-16.9%). Mild myopia predominated in the youngest (< 10 years) and oldest (> 70 years) age groups. Temporal trends in myopia prevalence and severity were analysed across the study period (2016-2024) and stratified by age groups, revealing a slight increase in mild myopia (55.2% to 58.9%), stability in moderate myopia (28.9% to 28.7%), and a gradual decrease in high myopia (15.9% to 12.4%). CONCLUSIONS: This nationwide study provides an updated overview of myopia prevalence and severity in Spain, highlighting a substantial burden, particularly of high myopia among young adults. Telemedicine in optometric centres offers a potential efficient approach for population-based screening, enabling early detection and targeted public health strategies to manage myopia and its complications.