Glaucoma, the leading cause of irreversible blindness, affects around 80 million people worldwide. The disease leads to vision loss when cells in the optic nerve and retina degenerate.
The existing pressure-lowering eye drops or surgery treatments may, at best, reduce the risk of further injury and slow down the process. However, it is not currently possible to protect cells from further damage or regenerate a damaged optic nerve in glaucoma and recover vision.
Earlier pre-clinical research has demonstrated that a form of vitamin B3 called nicotinamide could prevent optic nerve degeneration in animal models – but this is the first time similar results have been observed in a human trial.
Nicotinamide improved glaucoma patients' visual function
The results of the current study show significant improvement in the visual function of glaucoma patients who received a daily high dose of 3 grams of nicotinamide for 12 weeks in addition to their regular treatment to reduce eye pressure.
This study clearly demonstrates a robust protective effect for nicotinamide in existing glaucoma patients. This is very exciting as it provides more evidence to support longer-term clinical trials, says Assistant Professor Pete Williams at Karolinska Institutet and St. Erik Eye Hospital, one of the researchers behind the study.
57 glaucoma patients from Melbourne, Australia, were included in the study, all of whom received both placebo and nicotinamide alternately over the course of the study. The visual function was assessed using electroretinography, a diagnostic test which measures electrical activity in the cells of the retina, and visual field testing to determine any changes that occurred.
The study also provides the first evidence that visual function testing can be used as a clinical trial and diagnostic tool for detecting glaucoma progression. It could therefore be used to significantly shorten glaucoma clinical trial time and bring new treatments to patients sooner. Longer trials are needed to see if these changes in visual function correlate with structural changes in glaucoma patient retina and optic nerve, Pete Williams says.
Could be a viable glaucoma treatment
Nicotinamide is well tolerated in patients further suggesting its utility in the clinic. The researchers conclude that nicotinamide could be a viable glaucoma treatment and is advantageous as it is well tolerated, cheap, and easily available.
Although promising results longer international multi centre studies are needed to see if these early changes predict long term changes in glaucoma patients.
The study, led by the Centre for Eye Research Australia, also included researchers from the University of Melbourne, Duke NUS-Medical School, Singapore Eye Research Institute, Karolinska Institutet/St. Erik Eye Hospital, University of Adelaide and Cambridge University.
Funding for this study was provided by the Ophthalmic Research Institute of Australia, the Victorian Government’s Operational Infrastructure Program, Jack Brockhoff Foundation, Marian and EH Flack Trust, Jean Miller Foundation, Connie and Craig Kimberley Fund, Vetenskapsrådet and Board of Research Faculty at Karolinska Institutet.
Improvement in Inner Retinal Function in Glaucoma with Nicotinamide (Vitamin B3) Supplementation: A Crossover Randomised Clinical Trial, Hui F, Tang J, Williams PA, McGuinness MB, Hadoux X, Casson RJ, Coote M, Trounce IA, Martin KR, van Wijngaarden P, Crowston JG, Clinical and Experimental Ophthalmology, online 29 July, 2020, doi: 10.1111/ceo.13818