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

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.

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.

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