Objective: To evaluate the risk of primary open-angle glaucoma (POAG) development in type 2 diabetes mellitus (T2DM) patients.

Methods: In this 11-year longitudinal study based on the Korean National Health Insurance research database, the data collected comprised 1,025,340 (2.2%) participants who were randomly selected from 46,605,433 Korean residents in 2002. The database was analyzed to identify participants with an initial diagnosis of T2DM in 2003-2004. The control group was composed of participants without T2DM who were propensity-score-matched, five controls per T2DM patient, according to age, gender, household income, residential area and underlying diseases, including hypertension, dyslipidaemia, coronary heart disease, cerebrovascular disease and thyroid disease. Cox proportional-hazards regression was used to calculate the overall hazard ratios (HRs) in participants with and without T2DM for development of POAG before and after adjusting for confounding factors.

Results: There were 12,657 participants with T2DM and 63,285 propensity-score-matched controls without T2DM. POAG developed in 413 (3.3%) and 1188 (1.9%) participants in the T2DM and control groups, respectively. T2DM was associated with an increased risk of POAG development [HR: 1.80; 95% confidence interval (CI): 1.58-2.04] after adjusting for age, gender, household income and other potential confounders.

Conclusions: T2DM was significantly associated with the development of POAG after adjusting for potential confounders in the Korean population.