The researchers at the Centre for Eye Research Australia, University of Melbourne, Duke NUS-Medical School, Singapore Eye Research Institute, Karolinska Institutet, University of Adelaide, and Cambridge University, published the findings in Clinical & Experimental Ophthalmology.

This is also the first time that the researchers found improvements in a glaucoma therapy that does not involve the lowering of pressure in the eye, research fellow Dr Flora Hui told NutraIngredients-Asia. 

Previous research has shown that glaucoma patients have low NAM serum level, and NAM supplementation could protect the retinal ganglion cells in preclinical models.

This study had validated the protective properties of NAM in humans, with improvement in inner retinal function and improved energy supply to the nerve cells seen in subjects.

“By studying how cells in glaucoma behaved, we found that there may be an energy deficiency in the nerve cells in the eye, and that the pathways responsible for creating the energy supply weren’t working properly.

“NAM can allow for more efficient energy production for cells to hopefully work better and survive for longer to prevent loss of vision,” she explained.

The research had received funding from a number of organisations, such as The Ophthalmic Research Institute of Australia and Jean Miller Foundation.

Fifty-seven glaucoma patients were recruited into the study between October 2017 and January last year.

Randomised into two groups, they received either oral placebo or NAM.

The experiment group took 1.5g of NAM once daily for the first six weeks. The daily dosage was doubled for the next six weeks.

After 12 weeks, subjects on placebo had to take NAM and vice versa.

The inner retinal function of patients was tested using electroretinography – a diagnostic test which measures electrical activity in the cells of the retina. Visual field testing was also conducted to determine changes that occurred.

Findings

Results showed that there were significant improvements in inner retinal function in subjects receiving high-dose NAM.

Specifically, they have more energy supplied to the nerve cells in the eyes, as the amplitude of their photopic negative response (PhNR) improved by 14.8%, while that of placebo improved by 5.2%. 

“For the first time, we have provided evidence that oral NAM supplementation leads to an early and measurable improvement in inner retinal function in glaucoma patients already taking IOP-lowering medication,” the researchers said

Next steps

Currently, it is not a common practice for doctors to prescribe vitamin B3 to glaucoma patients.

However, Dr Hui said that with an upcoming study, they could determine more conclusively if NAM should be taken on an ongoing basis in people with glaucoma.

The new study would be a larger and longer trial, with the aim of finding out whether the improvements seen in the present study have lasting effects in reducing the progression of the disease.