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Key Points
- NAM strengthened optic nerve signals
- Retinal cell activity improved
- Eye pressure and structure remained stable
- Well tolerated with no serious adverse events
Overview of Study
Fifty-three adults with glaucoma were randomized to receive either oral placebo or NAM for 12 weeks, followed by a crossover to the other treatment for 12 weeks.
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NAM First:
- 6 weeks of 1 g/day NAM, increased to 6 weeks of 2 g/day NAM, followed by 12 weeks of placebo
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Placebo First:
- 12 weeks of placebo, followed by 6 weeks of 1 g/day NAM, increased to 6 weeks of 2 g/day NAM
Researchers measured retinal electrical signals, eye pressure, side vision, and safety.
Retinal Function Significantly Improved
NAM participants showed improvements in inner retinal responses. Nerve cells responded more strongly to light and supporting retinal cells also showed better signal strength.
PhNRPT, a signal showing how well the eye's main nerve cells are working, increased significantly, suggesting improved retinal nerve cell activity.
- NAM group: +3.12 µV
- Placebo group: +1.00 µV
Similarly, the B-wave, a signal that reflects inner retinal support cell activity, increased suggesting improved retinal signal processing.
- NAM group: +2.11 µV
- Placebo group: +0.31 µV
"At the 12-week visit, the amplitude changes in the PhNRPT and the B-wave was significantly greater in the NAM treatment."
Taken together, these findings show that NAM enhanced how efficiently the inner retina processed visual signals, even over a relatively short treatment period.
Research shows restoring cellular NAD⁺ supports neuronal energy metabolism and signal transmission across multiple neurodegenerative conditions.
Eye Pressure and Structure Remained Stable
In glaucoma, high eye pressure can damage the optic nerve over time, and lowering intraocular pressure (IOP) is the standard treatment.
IOP and the thickness of the retinal nerve fiber layer (RNFL) stayed the same and retinal function improved. This suggests the benefits came from changes within retinal cells rather than from pressure reduction or visible structural changes.
"No significant differences were observed between the placebo and NAM groups in either IOP or cpRNFL thickness."
Vision tests were similar between the two groups, suggesting NAM did not negatively affect vision performance and showed acute signs of improvement.
"VF indices were not different between groups, the number of pointwise improvements… was greater in NAM-treated eyes, without reaching statistical significance."
Importantly, NAM was well tolerated, and no serious adverse events were reported.
"Oral NAM supplementation at a dosage of 2 g/day in NTG participants demonstrated no serious side effects."
Conclusion
In adults with glaucoma, short-term NAM enhanced retinal function without changing eye pressure or retinal structure, indicating functional benefits independent of pressure reduction.
"NAM supplementation resulted in early and measurable improvements in inner retinal function among participants with NTG already receiving IOP-lowering treatment."
These results align with prior studies showing NAD-boosting nutritional support may offer a complementary approach to age-related vulnerability of the visual system.
"These findings support prior experimental research suggesting a neuroprotective role for NAM in glaucoma and highlight the need for long-term studies to determine its potential in slowing disease progression."
Research on direct NAD⁺ delivery to neural tissues provides additional context for how NAD⁺ restoration may support retinal and optic nerve health.
