Researchers at the National University of Singapore (NUS) have developed a light-activated treatment for dry eye disease using photosynthetic membranes extracted from spinach leaves. Preclinical studies indicate the treatment reversed corneal damage to near-healthy levels within five days. The findings were published in the journal Cell on May 15, 2026.
The Technology
The technology, named LEAF (Light-reaction Enriched thylAkoid NADPH-Foundry), consists of nanosized thylakoid grana membranes derived from spinach. These particles are approximately 400 nanometers (nm) in size and are produced using a mild mechanical and chemical extraction method. The technology produces approximately 20% more NADPH than unpackaged thylakoids.
When applied as eye drops, the particles are absorbed by corneal cells. Upon exposure to ambient light, they produce NADPH, a molecule that neutralizes reactive oxygen species (ROS). In laboratory tests on inflamed cells, LEAF restored NADPH levels within 30 minutes of light exposure, suppressed ROS, and shifted immune cells to an anti-inflammatory state. In tear samples from dry eye patients, LEAF increased NADPH roughly 20-fold and reduced hydrogen peroxide by over 95%.
"The treatment is delivered as eye drops at doses that do not interfere with color perception."
Preclinical Findings
In preclinical studies, LEAF eye drops reversed corneal damage to near-healthy levels within five days under ambient indoor lighting. The treatment demonstrated improved outcomes compared to the existing drug Restasis® (cyclosporine A). Safety assessments conducted over two months reported no adverse effects.
Background and Context
Dry eye disease, also known as keratoconjunctivitis sicca, affects over 1.5 billion people worldwide. The condition involves a cycle of inflammation and ROS generation that can overwhelm the cornea's natural antioxidant defenses. Current treatments, including cyclosporine A (Restasis®) and lifitegrast (Xiidra®), target inflammation but have associated limitations, including high cost and side effects.
The research was inspired by the sacoglossan sea slug, which can photosynthesize by incorporating chloroplasts from algae into its cells. The eye was chosen as a target tissue because it absorbs visible light, similar to plant leaves.
Dr. Xing Kuoran, first author of the study, stated: "This is an exciting finding as we have, for the first time, demonstrated that plant photosynthetic machinery can be transplanted into mammalian tissue to generate biologically useful molecules, powered entirely by the same light that enables our vision. We, too, can have limited photosynthetic abilities."
Future Plans
The research team plans to conduct clinical trials and is exploring applications for the technology in other tissues accessible to light, including the retina, skin, and skeletal muscles.