Researchers have developed a potential new treatment for glaucoma, a common eye disease, which could replace daily drops and surgery with an injection twice a year to lower pressure in the eye for several months.

Glaucoma is an eye disease characterized by damage to the optic nerve, most often due to increased pressure inside the eye. In glaucoma, the nerve endings of the optic nerve are damaged in the retina and the optic nerve gradually loses its fibers. This results in a progressive impairment of the field of vision, the space that the eye sees gradually reducing: the vision disappears on the sides and then if the lesions progress, the central vision disappears. According to Health Insurance, glaucoma affects 1 to 2% of the population over 40 and 10% after 70, and is the second cause of blindness in France after age-related macular degeneration (AMD).

There is no treatment that can cure glaucoma, as those currently used aim to protect the optic nerve by reducing intraocular pressure and thus limit the progression of the disease. Drug treatment (eye drops) is often offered as a first-line treatment and secondly, the doctor may suggest laser treatment performed in the office. Finally, if the glaucoma is resistant to previous treatments and if the sight continues to decline, surgery may be considered. Researchers at the Georgia Institute of Technology are currently working to develop a non-drug, non-surgical, long-acting treatment for glaucoma.

Open the aqueous humor drain filter

  Their study published in the journal Advanced Science specifies that this treatment would act as an alternative to daily eye drops and surgery, being given as an injection under the surface of the eye twice a year to control the accumulation. pressure in the eye. Researchers envision the injection as a simple procedure that could be part of regular patient visits. Concretely, the patient would be injected with a hydrogel in order to open an alternative way to facilitate the evacuation of the aqueous humor. A liquid constantly produced inside the eye and then discharged through a filter located between the iris and the cornea. 

 However, if the evacuation of the liquid is slowed down, the pressure inside the eyeball rises abnormally and causes damage to the fibers of the optic nerve. "The holy grail for glaucoma is an effective pressure-reducing method that doesn't depend on the patient who puts eye drops in their eyes every day, doesn't require complicated surgery, has minimal side effects and has a good profile." of security. "Said Professor Ross Ethier, co-author of the study supported by the National Eye Institute and the Georgia Research Alliance. “I am very excited about this technique, which could be a game-changer for the treatment of glaucoma. "

A single treatment that lasts six months?

  The process involves using a small, hollow needle to inject a polymer preparation into a structure just below the surface of the eye called the suprachoroidal space (SCS). Once inside the eye, the material chemically turns into a hydrogel, which keeps a channel open in the SCS to allow the aqueous humor present to flow out of the eye. There are normally two routes for the aqueous humor fluid to leave the eye. The dominant path is through a structure known as the trabecular meshwork, located at the front of the eye. The other route is through the SCS which normally only has a very small space.

“In glaucoma, the dominant pathway is blocked, so to lower the pressure, treatments are created to open the smaller path enough to let the aqueous humor flow out. ", Note the researchers. This hydrogel injection keeps the SCS port open and therefore reduces the pressure continuously for a period of four months. “By opening up this space, we are exploiting a pathway that otherwise would not be used effectively to remove fluid from the eye. The injection performed by an eye specialist just would take just a few minutes and the study states that the scientific team did not observe any significant inflammation resulting from the procedure.

Researchers are working to extend that time frame by modifying the polymeric material, hyaluronic acid, with the goal of providing effective treatment for six months, which would coincide with the schedule of office visits for many patients. “The injection could be done in the office during routine examinations that patients already undergo. They may not need to do anything to treat their glaucoma until their next visit, ”they stress. In addition to extending the time between treatments, the researchers must demonstrate that the injection can be repeated without harming the eye but also test the procedure on other animals before conducting trials on humans.