This study was done to describe the cohort profile of the NICOLA and to report the prevalence, awareness, and associations with glaucoma.

Using geographic stratification, a representative sample of non-institutionalized Northern Irish adults aged over 50 years was invited to participate. NICOLA participants underwent a CAPI, an SCQ, and a health assessment. The CAPI and SCQ collected comprehensive sociodemographic and health-related data. At the health assessment, participants underwent optic disc stereo photography, IOP measurement using ORA, autorefraction, spectral-domain optical coherence tomography, and self-reported history of glaucoma. NICOLA participants suspected of having glaucoma due to optic disc appearance or raised IOP for clinical examination by a glaucoma expert and perimetry were invited to take part in the study.

Of the total of 3221 NICOLA participants who attended the health assessment component of the NICOLA study, 91 participants were the ones who had glaucoma. Overall, the crude prevalence of glaucoma was 2.83% and 67% of affected individuals did not give a self-reported history of glaucoma.

The findings of the study concluded that the prevalence of glaucoma in Northern Ireland is comparable with other population-based studies of European populations. Approximately two-thirds of people with glaucoma were undiagnosed.