Global Prevalence of Dry Eye Disease in Medical Students: A Systematic Review and Meta-Analysis.

Dry Eye Disease (DED) is a multifactorial condition increasingly affecting young populations, including medical students, due to intensive screen use, prolonged near work, and demanding academic environments. This study aimed to estimate the prevalence of DED-related outcomes among medical students and to examine how estimates vary according to diagnostic methods, methodological characteristics, and publication period. A systematic review with meta-analysis was conducted. PubMed, Scopus, Web of Science (including SciELO), and EMBASE were searched from January 2000 to March 2026. A random-effects model was applied, and subgroup, sensitivity, and exploratory meta-regression analyses were performed. Twenty-seven studies were included, comprising 12,501 participants. The pooled prevalence of DED-related outcomes was 47.4% (95% CI: 38.4-56.4%); however, between-study heterogeneity was extreme (I2 = 99%). Therefore, this estimate should be interpreted as an approximate summary of a highly heterogeneous evidence base rather than as a definitive global epidemiological value. Prevalence estimates varied according to diagnostic approach, particularly between self-report, symptom questionnaires, and clinical tests. Exploratory meta-regression suggested a positive association with publication year, but these analyses did not meaningfully resolve heterogeneity and should not be interpreted as causal evidence of a temporal increase. Standardized diagnostic approaches combining symptoms and ocular surface signs are needed to improve comparability across studies and inform preventive visual-health strategies in medical education.