Age-related macular degeneration (AMD) is a leading cause of vision loss in older adults, but is challenging to catch early. Researchers at Massachusetts Eye and Ear have discovered a group of metabolites that could be used to improve the diagnosis and treatment of AMD.

The Massachusetts Eye and Ear team studied metabolites, or small molecules in the blood of patients with early, intermediate and late-stage AMD, as well as from individuals without AMD. "The metabolome—the set of metabolites present in an individual—is thought to closely represent the true functional state of complex diseases," said first author Ines Lains, M.D., a research fellow at Massachusetts Eye and Ear, in a statement.

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They found 87 metabolites that were "significantly different" in people with AMD and those without. These molecules also differed between patients with different stages of AMD. This method, dubbed "metabolomics," could enable the early diagnosis of AMD, allow doctors to personalize treatment for each patient and highlight potential new targets for treatments. The work is published in the journal Ophthalmology.

Most of the 87 AMD-linked molecules played a role in the lipid pathway, and a handful of them were lipids themselves. Lipids are known to influence AMD, but their exact role is unclear. The study suggests that metabolomics profiling may reveal how, exactly, lipids affect disease progression.

AMD is the deterioration of the macula, an area close to the retina. Current treatments, which are injected directly into the eye, focus on inhibiting VEGF, thereby plugging the leaky blood vessels that are the signature of the disease. But this mechanism can only delay disease progression. There is an ongoing battle for market share between Novartis’ Lucentis, once the leading treatment for "wet" or neurovascular AMD, and Regeneron and Bayer’s Eylea, which is cheaper and requires less frequent injections. Novartis recently announced positive data from two phase 3 trials of its new long-acting VEGF inhibitor, which needs to be injected only four times a year.

The Massachusetts Eye and Ear researchers believe metabolomics could produce alternatives to the one-size-fits-all approach to treating AMD. "Our work gives us a novel biomarker for early diagnosis, and it gives us clues to differentiate the progressers from non-progressors," said co-author and retina specialist Deeba Husain in the statement.

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