Why This Matters
Glaucoma is the leading cause of irreversible blindness worldwide, and it operates silently. Most people with elevated eye pressure, the primary modifiable risk factor for the most common form of glaucoma, have no symptoms. They may go years without a diagnosis while the optic nerve gradually sustains damage that cannot be reversed.
Standard clinical management of elevated eye pressure, a condition called ocular hypertension, typically involves monitoring and eye drops if pressure rises to dangerous levels. There are no established neuroprotective therapies: no drugs specifically designed to protect the optic nerve from early damage independent of pressure reduction.
A study published in JAMA Ophthalmology and reported by multiple clinical outlets in July 2026 suggests that an inexpensive, widely available vitamin supplement may offer exactly that kind of protection, reducing the rate at which people with elevated eye pressure develop glaucoma by two-thirds. The effect is large enough that the medical community is taking it seriously — and cautious enough that clinical guidance has not yet changed.
What We Know So Far
Researchers led by Jawad Muayad and colleagues published their findings in JAMA Ophthalmology (DOI: 10.1001/jamaophthalmol.2026.2472). They analyzed anonymous electronic health records from 67 U.S. healthcare organizations spanning March 2006 to March 2026 — a 20-year real-world window.
The study identified 2,920 patients with documented ocular hypertension who had not yet been diagnosed with primary open-angle glaucoma (POAG). Half, 1,460 individuals with a mean age of 54.4 years, had at least one recorded instance of nicotinamide supplementation. They were matched to 1,460 controls of similar age, sex, and medical history with no history of nicotinamide or niacin use.
Over a mean follow-up of 3.7 years, 51 patients in the nicotinamide group (3.5%) developed primary open-angle glaucoma, compared with 132 patients in the control group (9.0%). The hazard ratio was 0.34, representing a statistically significant 66% relative reduction in glaucoma risk. The absolute risk reduction was 5.5 percentage points.
Secondary findings were equally striking. Nicotinamide users were 43% less likely to require topical intraocular pressure-lowering therapy (13.6% versus 21.2%), and 62% less likely to undergo laser trabeculoplasty surgery (0.8% versus 1.9%).
Where the Risk Is Highest — and Where Nicotinamide May Matter Most
Ocular hypertension is common and under-recognized. The most widely cited estimate is that 3 to 6 million Americans have elevated intraocular pressure that puts them at increased risk of developing primary open-angle glaucoma, according to a foundational 2002 JAMA Ophthalmology paper. Globally, approximately 95 million people have glaucoma.
The study's strongest beneficiary appears to be people with moderate ocular hypertension who have not yet developed glaucoma and are currently on a watch-and-wait approach. A sensitivity analysis among patients who received their first nicotinamide prescription only after an ocular hypertension diagnosis (947 matched pairs, mean follow-up 4.2 years) showed nicotinamide remained protective, with a 58% reduction in glaucoma risk. This rules out the possibility that all the benefit came from patients who happened to start taking nicotinamide before elevated pressure was even detected.
Patients with higher baseline HBsAg levels faced lower benefit, consistent with the idea that earlier, more aggressive intervention carries greater protective potential.
What Doctors and Experts Say
The accompanying editorial in JAMA Ophthalmology by Simon K. Law framed the finding as one of the strongest real-world signals yet for nicotinamide's neuroprotective potential, while noting that "it would be highly beneficial to have additional studies explore the exact dose" given that the study categorized any recorded nicotinamide use as "exposure" without capturing dose, duration, or formulation.
Ophthalmology experts commenting to Medical News Today noted that nicotinamide's mechanism in this context is thought to involve supporting retinal ganglion cell energy metabolism and protecting those cells from the metabolic stress associated with elevated intraocular pressure, a different pathway from simply lowering eye pressure.
However, the American Glaucoma Society and the American Academy of Ophthalmology issued a joint statement in March 2025 regarding the safety of nicotinamide supplementation. They specifically noted that high-dose nicotinamide, at 3 grams per day as used in some ongoing clinical trials, carries a risk of liver damage. That safety concern means this is not a supplement to begin without a clinician's input, particularly at doses higher than typical dietary supplement formulations.
What the Evidence Shows and What It Does Not
This is a large retrospective cohort study using real-world electronic health records. Its strengths are its scale (2,920 patients), its duration (20 years), and its propensity score matching methodology, which controls for known confounders. These features make it among the most persuasive observational data yet published on nicotinamide and glaucoma.
Its limitations are equally important. The study cannot account for all unmeasured confounders: people who seek out nicotinamide supplementation may differ systematically from those who do not in diet, health literacy, access to care, and other behaviors that independently affect glaucoma risk. The dose of nicotinamide was not captured; all recorded users were treated equally regardless of whether they took a low-dose supplement or a therapeutic dose. Long-term safety at the doses associated with the protective effect is unknown.
A randomized controlled trial is the standard of proof needed before clinical guidance changes. Ongoing RCTs are evaluating nicotinamide in glaucoma prevention, but results are not yet available.
MedicalDaily Evidence Check
- Study type: Retrospective real-world cohort study with propensity score matching
- Data source: Electronic health records from 67 U.S. healthcare organizations, March 2006 to March 2026
- Participants: 2,920 patients with ocular hypertension; 1,460 nicotinamide users, 1,460 matched controls
- Published in: JAMA Ophthalmology (DOI: 10.1001/jamaophthalmol.2026.2472)
- What it found: 66% lower relative risk of developing primary open-angle glaucoma; 43% reduction in need for eye drops; 62% reduction in laser trabeculoplasty
- What it did not prove: That nicotinamide prevents glaucoma; optimal dose, duration, formulation, and long-term safety remain undetermined; no RCT evidence exists
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What readers should know: This is a significant observational finding that warrants clinical attention — and also warrants caution about self-supplementing at high doses before guidance evolves
Who Faces the Greatest Risk?
People most likely to benefit from ongoing monitoring and from discussing nicotinamide with an eye-care specialist include:
- Adults with documented ocular hypertension who have not yet developed glaucoma
- People over 60, in whom glaucoma prevalence increases substantially
- African Americans, who have a significantly higher prevalence of glaucoma and typically develop it at younger ages than other groups
- People with a family history of glaucoma in a first-degree relative
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People with thin corneas, large optic nerve cups, or other structural risk factors identified during routine eye exams
Symptoms and Warning Signs to Watch For
Ocular hypertension and early primary open-angle glaucoma are typically asymptomatic. People do not notice elevated eye pressure or early optic nerve damage in most cases. Warning signs of advanced or acute glaucoma include:
- Gradual loss of peripheral (side) vision, often noticed only when significant damage has already occurred
- Blurry vision
- Seeing halos around lights
- Sudden severe eye pain, headache, nausea, and vomiting (these indicate acute angle-closure glaucoma, a medical emergency requiring immediate care)
The best strategy for detecting early glaucoma is regular comprehensive dilated eye exams, particularly for those over 40 with risk factors. Eye exams are the only way to measure intraocular pressure and evaluate the optic nerve before damage becomes irreversible.
What You Can Do Now
- If you have been told you have elevated eye pressure (ocular hypertension) and are on a watch-and-wait approach, discuss this study with your ophthalmologist at your next appointment. Ask whether nicotinamide is worth considering in your specific case, and at what dose.
- Do not start high-dose nicotinamide supplementation without speaking with a clinician first. The American Glaucoma Society and American Academy of Ophthalmology have noted that doses used in some clinical trials (3 grams per day) carry a risk of liver toxicity.
- Stay current with recommended eye exams. Adults over 40 with risk factors (African American descent, family history, elevated pressure) should have comprehensive dilated eye exams at least every one to two years.
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Do not stop prescribed glaucoma treatments (eye drops, laser therapy) based on this study. Nicotinamide has not been shown to replace intraocular pressure lowering as a primary management strategy.
Cost and Access: What Patients Should Know
Nicotinamide (also called niacinamide) supplements are widely available over the counter at low cost at most pharmacies and health food retailers. They are distinct from niacin (nicotinic acid), which causes flushing, and from niacinamide in skincare products. Standard supplement doses range from 250 mg to 500 mg per tablet.
The doses used in clinical trials targeting glaucoma are substantially higher, typically 1.5 to 3 grams per day, and should not be started without medical supervision given the liver toxicity concern at higher doses.
A comprehensive eye exam, including intraocular pressure measurement, is covered by most vision insurance plans and by Medicare for beneficiaries with documented glaucoma risk factors.
What Happens Next
The JAMA Ophthalmology editorial called for ongoing randomized controlled trials to confirm the observational findings, determine optimal dosing, and establish long-term safety. Those trials are underway, though results are not expected in the near term.
GSK, which has a separate nicotinamide-related program in a different indication, and academic ophthalmology centers are among those conducting neuroprotection trials in glaucoma. Regulatory guidance from the American Glaucoma Society and American Academy of Ophthalmology is expected to be updated if and when RCT evidence confirms the finding.
The Bottom Line
A 20-year real-world study of nearly 3,000 Americans with high eye pressure found that those who took nicotinamide were 66% less likely to develop glaucoma, needed fewer eye drops, and underwent less laser surgery. The finding is among the most compelling observational evidence yet published on glaucoma prevention. But the study cannot prove causation, optimal dosing is unknown, and high doses carry a liver toxicity risk documented by leading ophthalmology societies. People with elevated eye pressure should discuss this finding with their eye doctor rather than self-supplementing, especially at high doses, before randomized trial evidence emerges.
