Experts have found a new way to deliver huge amounts of a turmeric-derived substance to the eyes to prevent glaucoma patients from going blind.
A team of eye doctors at University College London has developed eye drops containing curcumin, a substance found in the spice turmeric giving it its bright yellow color.
After administering the eye drops to laboratory rats suffering from early-stage glaucoma, the researchers found that it significantly reduced the loss of retinal ganglion cells characteristic of the disease.
What Is Glaucoma?
Curcumin has long been used in alternative medicine. When taken orally, the substance can protect glaucoma patients from blindness.
However, the substance has poor solubility, which means it dissolves poorly in the bloodstream. For patients to fully harness the benefits of curcumin taken orally, they have to take at least 24 tablets every day, which can lead to gastrointestinal problems as a side effect.
Glaucoma is an eye disease characterized by the loss of retinal ganglion cells, neuron cells found near the surface of the retina, the thin layer of tissue at the back of the eye that receives and processes light.
It happens when the optic nerve, the nerve that connects the eye to the brain, gets damaged. More than 6 million people in the world suffer from glaucoma-induced blindness. In the United States alone, more than 3 million people have this eye disease, which is the second leading cause of irreversible blindness in the world.
To date, experts have not yet discovered a way to keep the loss of nerve cells from progressing during the early stages of the disease. The new development can pave the way for a potential effective treatment to cure patients with early-stage glaucoma.
Curcumin Eye Drops
Researchers at UCL's Institute of Ophthalmology and School of Pharmacy administered the curcumin eye drops to rats with eye diseases that involved the loss of retinal ganglion cells, similar to the early stages of glaucoma. The rats received the treatment two times every day for three weeks.
The results, published in the Scientific Reports journal, show a significant reduction of nerve cell loss in the rats after the three-week treatment.
To develop the eye drops, the team devised a nanocarrier composed of a surfactant and stabilizer to transport the curcumin to the eyes. The materials used are known safe for human use and are being used in existing eye drops.
The nanocarrier can deliver high levels of curcumin straight to the back of the eyes where the retina is found, surpassing the solubility problem. It also increases absorption by a factor of 400,000, ensuring that the nerve cells receive the appropriate amounts of the substance.
The researchers first tested the eye drops on cells mimicking glaucoma before using the eye drops on the rats, which tolerated the eye drops well and showed no sign of adverse side effects.
They are hoping to conduct further testing to see if the eye drops can also be used as a diagnostic tool for other neurodegenerative diseases, such as Alzheimer's disease.
"Curcumin is an exciting compound that has shown promise at detecting and treating the neurodegeneration implicated in numerous eye and brain conditions from glaucoma to Alzheimer's disease," says study lead Francesca Cordeiro of UCL's Institute of Ophthalmology, "so being able to administer it easily in eye drops may end up helping millions of people."