Effect of Niacinamide Supplementation in Glaucoma

100 subjects with primary open-angle glaucoma will be enrolled from two centres (CMI profesor doctor Liliana Mary Voinea Bucharest Eye Centre and SC Optispecs Med SRL TgJiu Eye Clinic).

Participant Selection P1. Inclusion criteria

A subject will be eligible for inclusion in this study only if all of the following criteria apply:

• Patients aged 18 years or older;
• Confirmed diagnosis of Primary Open angle Glaucoma (POAG) - following a complete ophthalmological examination (ocular tonometry, slit lamp ocular examination, visual field and Optical coherence tomography);
• Subject has provided signed and dated written informed consent before admission to the study.
• Subject is able to understand and comply with the protocol requirements, instructions, and protocol-stated restrictions.
• Participants need to have visual acuity of Snellen ≥ 6/12 (0.5) or better.
• Have performed at least two reliable VFs (SITA-Fast 24-2), with <33% fixation losses and <15% false positives
• Those taking NAM already will undergo a 1-month washout period before commencing the study.

P2. Exclusion criteria

A subject will not be eligible for inclusion in this study if any of the following criteria apply:

• Participants must not be pregnant or breastfeeding women;
• Investigator considers the subject unfit for the study as a result of medical history, physical examination, or screening tests;
• VF damage worse than -10dB in the best eye and -16dB in the worse eye or a paracentral spot with -10dB or less in any eye),
• IOP >35mmHg in any eye or a mean IOP of 30mmHg or higher (two measurements), •inability to perform VFs,
• those unwilling to abstain from NAM supplements,
• allergic to niacinamide/niacin,
• diagnosed with cancer in the last 5 years (except treated basal or squamous cell carcinoma),
• a history of liver disease or stomach ulcers,
• disease that prevents long-term follow-up,
• neurologic or other non-glaucomatous conditions apart from cataract that may affect the VF
• Patient is diagnosed with primary angle closure glaucoma;
• Patient is diagnosed with secondary glaucoma (e.g. posttraumatic, postinflammatory, steroid induced, pseudoexfoliative, pigmentary, etc.);
• Patient is diagnosed with very advanced glaucoma (foveal fixation threatened or absent and, thus, unreliable perimetry);
• Patient is diagnosed with other significant ocular pathologies (advanced cataract, pathologic myopia, corneal ectasias or dystrophies, sever amblyopia, vitreoretinal disease, active ocular inflammation, significant sequelae of ocular inflammation);
• Unreliable ophthalmological investigations and non-compliance with examinations (e.g. high percentage of false negative and false positive errors when examining the visual field).

Participants will:

• Take NAM every day for 1 year
• Visit the clinic at 3, 6, and 12 months for check-ups and tests

Outcome Measures M1. Ophthalmological parameters

• Visual field parameters:

• Mean deviation (MD)
• Pattern standard deviation (PSD)
• Optical coherence tomography parameters: peripapillary retinal nerve fiber layer thickness (pRNFL);
• Visually evoked potential parameter: latence of P2 wave when using a flash stimulus.

M2. Quality of life measurement

➔ Glaucoma Quality of Life-15 questionnaire

Inclusion criteria

• Patients aged 18 years or older;
• Confirmed diagnosis of Primary Open angle Glaucoma (POAG) - following a complete ophthalmological examination (ocular tonometry, slit lamp ocular examination, visual field and Optical coherence tomography); Subject has provided signed and dated written informed consent before admission to the study.
• Subject is able to understand and comply with the protocol requirements, instructions, and protocol-stated restrictions.
• Participants need to have visual acuity of Snellen ≥ 6/12 (0.5) or better.
• Have performed at least two reliable VFs (SITA-Fast 24-2), with <33% fixation losses and <15% false positives
• Those taking NAM already will undergo a 1-month washout period before commencing the study.

Exclusion criteria

• Participants must not be pregnant or breastfeeding women;
• Investigator considers the subject unfit for the study as a result of medical history, physical examination, or screening tests;

•● VF damage worse than -10dB in the best eye and -16dB in the worse eye or a paracentral spot with -10dB or less in any eye),

• OP >35mmHg in any eye or a mean IOP of 30mmHg or higher (two measurements), •inability to perform VFs,
• those unwilling to abstain from NAM supplements,
• allergic to NAM/niacin,
• diagnosed with cancer in the last 5 years (except treated basal or squamous cell carcinoma),
• a history of liver disease or stomach ulcers,
• disease that prevents long-term follow-up, neurologic or other non-glaucomatous conditions apart from cataract that may affect the VF
• Patient is diagnosed with primary angle closure glaucoma;
• Patient is diagnosed with secondary glaucoma (e.g. posttraumatic, post inflammatory, steroid induced, pseudo exfoliative, pigmentary, etc.);
• Patient is diagnosed with very advanced glaucoma (foveal fixation threatened or absent and, thus, unreliable perimetry);
• Participants who are currently on NAM will be asked to stop taking the tablets for a month prior to screening visit.
• Patient is diagnosed with other significant ocular pathologies (advanced cataract, pathologic myopia, corneal ectasias or dystrophies, sever amblyopia, vitreoretinal disease, active ocular inflammation, significant sequelae of ocular inflammation);
• Unreliable ophthalmological investigations and non-compliance with examinations (e.g. high percentage of false negative and false positive errors when examining the visual field).