Nicotinamide and Glaucoma

The investigators plan to recruit four groups, each containing 30 subjects: 1) pseudoexfoliative glaucoma, 2) High tension open-angle glaucoma, 3) Normal tension glaucoma 4) Age-matched controls. Those enrolled will undergo two visits including an ophthalmic exam, blood sampling, and at the first visit, distribution of nicotinamide tablets. We plan to recruit participants amongst glaucoma patients already followed at the Eye Clinic at Umeå University Hospital. Furthermore, age-matched controls will be recruited through lists from the population register at Statistics Sweden. Before enrolling any subject, they will receive both oral and written information as well as sign a consent form. Furthermore, they will be evaluated to make sure that they fulfill the inclusion- and exclusion criteria prior to inclusion. The ophthalmic exam includes measurement of IOP, perimetry, and OCT/A. Between visits, the participants will receive 1,5 grams of NAM per day the first week and 3 grams per day the second week. The blood drawn will initially be sent to Biobanken Norr for storage. Samples will then be sent to the Swedish Metabolomics Centre, Umeå University and Department of Medical Biochemistry and Biophysics, Karolinska University for analysis using high-resolution mass spectrometry.