Markers in the blood that predict whether glaucoma patients are at higher risk of continued loss of vision following conventional treatment have been identified by researchers at Moorfields Eye Hospital and UCL
Over 700,000 people in the UK have glaucoma and it is the leading cause of irreversible blindness worldwide.
The main risk factors for glaucoma are high eye pressure and older age.
Currently, all licenced treatments are designed to lower pressure in the eye. However, some patients still continue to lose their sight following this treatment.
To help doctors better understand who will lose their vision faster, this new study, published in Nature Medicine, asked whether mitochondrial function is lower in people with glaucoma than those without glaucoma, and if mitochondrial function is associated with the rate at which glaucoma patients lose vision.
Mitochondria are the ‘batteries’ inside cells that produce energy for the cells to function.
The researchers measured how well cells in the blood use oxygen, how much vision was lost over time and the levels of nicotinamide adenine dinucleotide (NAD), which helps cells produce energy and is made from Vitamin B3 in the diet.
Firstly, the researchers discovered that certain cells in the blood, known as peripheral blood mononuclear cells, use oxygen differently in people with glaucoma.
The team measured how much oxygen these cells use and found that people whose blood cells used less oxygen tended to lose their vision faster, even if they were being treated to lower intraocular pressure. This measurement explained 13% of the differences in the speed at which patients lost vision.
Additionally, people with glaucoma were found to have lower levels of NAD in their blood cells. These lower NAD levels were linked to the lower oxygen use in the blood cells.
Senior author, Professor David (Ted) Garway-Heath (Moorfields Eye Hospital and UCL Institute of Ophthalmology), said: “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.
“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 funded by the Medical Research Council and the National Institute for Health and Care Research, to establish whether high-dose vitamin B3 can boost mitochondrial function and reduce vision loss in glaucoma.
“We hope that this will open a new avenue for treatment of glaucoma patients which does not depend on lowering the eye pressure.”
15 July 2024