This study investigated the association between one-year surgical outcomes following trabeculectomy and age, accounting for confounding factors. Retrospective observational study. Analyzing data from 305 patients undergoing initial trabeculectomy from 2019 onward, we employed three approaches to adjust variables: stratified analysis, regression analysis, and propensity score matching. Surgical success at 1-year post-surgery was defined by two criteria: achieving intraocular pressure of between 5 and 15 mmHg with a ≥ 20% reduction compared to pre-surgery levels and no additional glaucoma surgery (Criterion A); achieving intraocular pressure of between 5 and 12 mmHg with a ≥ 30% reduction compared to pre-surgery levels and no additional glaucoma surgery (Criterion B). Stratified analysis by age unveiled a significant increase in exfoliation glaucoma (XFG) and a trend towards shorter axial lengths with advancing age (both p < 0.0001). Older age groups were more likely to experience surgical failure in both Criterion A and B (p = 0.21, < 0.01). Univariate analysis showed age as a significant factor in surgical failure for Criterion A (p < 0.05) and a nearly significant factor for Criterion B (p = 0.12). However, this trend was not evident in multivariate analysis (p = 0.23/0.88), where XFG became a significant factor for surgical failure (both p < 0.001) in Criteria A and B. Propensity score matching revealed no significant differences in surgical success rates for Criteria A and B between younger and older patients (p = 1.00 and 0.88). Age is not a primary determinant of failure in trabeculectomy; however, the increasing incidence of XFG with aging suggests a potential for poorer outcomes.