The eye is a "capsule" that is filled with a liquid known as aqueous humor; when its drainage system becomes clogged, it builds up causing increased pressure inside, damaging the optic nerve. This is usually how glaucoma develops, an eye disease that causes gradual vision loss.
The current treatment consists of implanting a valve in the eye, using surgery, to achieve good drainage of the aqueous humor; however, this has many limitations. Over time, it can become clogged, so it must stay that way because fixing it would mean performing a new surgery that could damage the eye a little more since it is a very invasive process.
The Markoptic Foundation, in conjunction with scientists from the National Laboratory of Biomimetic Solutions for Diagnosis and Therapy (UNAM), has designed a microvalve that does not clog so easily and is more efficient than conventional ones.
With a length of 1 mm and about 300 microns to half an mm in diameter, this device could be placed with a special applicator without the need for surgery, making it less invasive and easier to remove or replace if it becomes clogged.
"It works like a check valve that, when the pressure increases, rises and manages to drain the aqueous humor through an orifice. It was a challenge to manufacture it, as it is made up of three hair-sized pieces; to achieve this, several calculations and simulations were made to find the optimal way to design and assemble it," mentions Dr. Mathieu Hautefeuille, a member of the team.
For the moment, "we have several functional valves, with which pre-clinical tests will be carried out to check their effectiveness. We hope that they can soon be tested on humans", he concludes.
Glaucoma is the first cause of irreversible blindness in the world. One out of every two patients does not know they have glaucoma, even in developed countries. This figure is higher in countries like Mexico where there are an estimated 1.5 million people affected by the disease, according to the World Health Organization (WHO) figures.
This project was carried out thanks to the fact that the private industry approached the laboratory of the Faculty of Sciences of the UNAM to develop these valves with the effort of a multidisciplinary team.
It will be less invasive than a conventional valve, as no surgical intervention is required. It has a spring capable of being regulated according to the eye pressure of each patient, making the valve personalized.
Authors Pilar Martinez and Geraldine Ramirez, CyD