Mitochondrial function is associated with glaucoma treatment response

Researchers from University College London (UCL) and Moorfields Eye Hospital have identified biomarkers that may predict which glaucoma patients are at higher risk of continued vision loss, despite conventional treatment.

The study, published in Nature Medicine, examined whether mitochondrial function in white blood cells is lower in people with glaucoma than in healthy patients and whether it is associated with the rate at which glaucoma patients lose vision.

Enrolling 139 participants diagnosed with glaucoma and on treatment to lower intraocular pressure (IOP), plus 50 healthy individuals, researchers measured how well cells in the blood use oxygen, how much vision was lost over time, and nicotinamide adenine dinucleotide (NAD*) levels.

They discovered peripheral blood mononuclear cells use oxygen differently in people with glaucoma, and that people whose blood cells used less oxygen tended to lose their vision faster, even if they were on IOP-lowering treatment. This measurement explained 13% of the differences in how fast patients lost vision, they said.

Additionally, the blood cells of people with glaucoma were found to have lower levels of NAD compared to those without glaucoma. These lower NAD levels were also linked to the lower oxygen use in the blood cells.

“White blood cell mitochondrial function and NAD levels, if introduced as a clinical test, would enable clinicians to predict which patients are at higher risk of continued vision loss, allowing them to be prioritised for more intensive monitoring and treatment,” said senior author Professor David Garway-Heath. “If further research shows that low mitochondrial function or low NAD levels are a cause for glaucoma, then this opens the way for new treatments.”

UCL and Moorfields Eye Hospital are currently leading a major clinical trial to establish whether high-dose vitamin B3 can boost mitochondrial function and reduce vision loss in glaucoma, he added. “We hope that this will open a new avenue for treatment of glaucoma patients which does not depend on lowering the eye pressure.”

*The NAD molecule is derived from vitamin B3 and helps cells produce energy.