A new non-invasive eye imaging method may be able to detect an early indicator of glaucoma in time to prevent disease progression and vision loss, according to a new study from the New York Eye and Ear Infirmary of Mount Sinai (NYEE). ). The study was published in the July/August issue of Ophthalmology Glaucoma.
The study focused on measuring flavoprotein (FPF) fluorescence in the eye. Mitochondria – which are responsible for generating energy in cells – produce FPF when they are stressed, and FPF levels are elevated in people with glaucoma compared to people with normal eyes. Mitochondrial dysfunction in the optic nerve, which sends light signals to the brain and is critical for vision, can eventually lead to cell loss and tissue damage, causing various eye diseases such as glaucoma and macular degeneration, as well as other retinal damage. . This is the first comprehensive study to look at FPF changes in optic nerves in patients with different stages of glaucoma compared to healthy eyes.
“Glaucoma is difficult to diagnose in the early stages, and clinicians often agonize over confirming subtle signs of progression into advanced stages. Once structural damage to the optic nerve has occurred, it is currently not possible to reverse. Continued degeneration, more proactive we can be in implementing protective therapy,” says principal investigator Richard B. Rosen, MD, vice president and director of research in ophthalmology at NYEE and chief of the Mount Sinai Health System’s Retina Service. “Our study shows that FPF may be useful as an objective measure for predicting glaucoma progression earlier than measuring structural damage, with similar sensitivity to visual field changes but easier and potentially more consistent.”
A team of researchers used the OcuMet Beacon – a fundus camera with special filters that specifically isolates fluorescence, developed by OcuSciences Inc. – to analyze 86 eyes. Fifty of the eyes had glaucoma, based on thinning of the retinal fiber layer, and 36 had no disease. They found that FPF, an indicator of mitochondrial oxidative stress, was significantly higher in eyes with glaucoma compared with normal eyes, especially in cases of early-stage glaucoma where damage is difficult to detect. FPF levels correlated with other means of detecting glaucoma, including mean visual field deviation, visual field pattern deviation, and retinal nerve fiber layer thickness.
These results suggest that FPF can be used clinically to reliably and objectively detect metabolic evidence of injury due to glaucoma, limiting the need for frequent visual field testing, the gold standard for measuring visual function. In fact, the researchers say, FPF may be a more accurate measure, as visual fields have several drawbacks — they are subjective, fluctuate with patient attention, and patients can lose concentration during this assessment.
“Previous studies have shown that when mitochondrial oxidative stress is relieved by medication or surgery, flavoprotein fluorescence levels decrease. This makes the technique very attractive as a sensitive way to monitor response to therapy,” explains Dr. Rosen. “This measure could be used as a first-line indicator to monitor the progression of glaucoma for the patient and physician.”
The researchers say their next step is to see if FPF can reliably monitor the effect of therapy for patients with glaucoma, to see when treatment has flattened the risk curve of progression in advanced cases, as well as identify patients in need of intervention. early in glaucoma.