Swiss researchers have developed a contact lens capable of detecting the presence of glaucoma in 24 hours. Clinical trials are underway.
Glaucoma is the second leading cause of blindness in the world after the cataract. This disease, caused by too much pressure in the eye, is difficult to detect because it is painless and invisible. Screening is often too late, with the optic nerve already damaged. Researchers at the Ecole Polytechnique de Lausanne and Tissot Medical Research have developed contact lenses specially designed to detect glaucoma.
The only screening test available at this time is the measurement of intraocular pressure using specialized equipment available to ophthalmologists. But the intraocular pressure varies during the day, which makes this means of detection more or less reliable. In France, nearly 400 000 of the 600 000 people suffering from glaucoma are unaware that they suffer from this disease.
One measure at each blink
Swiss researchers have therefore been working on the development of a single-use contact lens capable of continuously measuring intraocular pressure for 24 hours. Composed of silicone and a set of sensors, it measures the pressure with each blink of the eyes. "When the eyelid closes, a slight bump exerts pressure on the cornea, bringing the electrodes closer together," says Luc Tissot, founder of Tissot Medical Research.
Small antennas are attached to the patient's glasses, capturing the data recorded by the lenses. A small portable unit collects all data for 24 hours. The ophthalmologist simply has to plug his USB key into the case and analyze the results on his computer. Clinical trials are currently underway at the Vaud University Hospital Center in Switzerland.
Glaucoma: treatments evolve
The second cause of blindness in France, glaucoma affects 1 to 2% of the population over 40 years and about 10% after 70 years. If this disease of the eye is not cured, its progression can be stopped by different treatments that keep evolving.
Glaucoma is most often due to an increase in intraocular pressure, which causes progressive destruction of the optic nerve. This pressure build-up is itself caused by an accumulation of "aqueous humor", the intraocular fluid that feeds the lens and the cornea. In order to stop its evolution, the various existing treatments aim to promote the evacuation of this liquid or to limit its secretion. "The first treatment is to instill in the eye eye drops based on prostaglandins or β-blockers," explains Christophe Baudouin. Unfortunately, "the preservatives they contain often cause irritation, dry eyes and long-term intolerance." But things are changing.
DMD: at what age should we be tested?
The narrowing of the visual field is one of the first perceptible symptoms of glaucoma. But it intervenes at an already advanced stage, whereas an irreversible damage to the optic nerve has already taken place. In order to detect glaucoma before it occurs, it is necessary to consult an ophthalmologist, especially if you are over 45 years old or have a family history. Since 2010, the National Union of the Blind and Visually Impaired has set up a mobile screening antenna. For its tour 2013-2014, it will pass through 35 cities including Toulon, Nice and Dijon in February and Paris and Grenoble in March.
More tolerate eye drops:
Formulations containing several active principles, thus limiting the number of eye drops to be used, as well as β-blockers without preservatives, have been created. And since the beginning of this year, the first preservative-free prostaglandin eye drops have been marketed. If eye drops are meant to lower eye strain, it varies considerably throughout the day. It would be better to install them at the moment when it is the highest. Except that, for the time being, the ophthalmologist has no means to determine this critical moment and, by default, he tells patients standard schedules. Soon, this may not be the case anymore. A flexible lens capable of continuously measuring eye tension for 24 hours is currently being tested in several French hospitals.
Ultrasound to operate:
When eye drops do not work, surgery often needs to be considered. "In one-third to one-half of the cases, it is a failure: the incisions in the eye to remove the liquid are refilled," says Florent Aptel. A new treatment offers an answer to these patients in therapeutic failure. This involves destroying some of the tissues that secrete the aqueous humor using an intense and localized flow of ultrasound. "As we do not open the eye, there is no risk of infection. The procedure lasts only 2 minutes, can be done in outpatient surgery and does not cause or few side effects, "details Philippe Denis. A dozen hospitals are equipped with this technology.
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Evil screening, glaucoma is an eye disease that can lead to total blindness. For this reason, a screening bus will circulate in some twenty French cities by July.
On the occasion of World Glaucoma Week, from March 9th to 15th, a free screening campaign was organized by the French glaucoma society (SFG) and the national union of the blind and visually impaired (Una de). A screening bus was installed on the Place de la Nation in Paris, and will then travel to some twenty French cities until July.
This ocular disease, often asymptomatic, is the second cause of blindness in developed countries. Caused by too much pressure inside the eye, glaucoma can be treated to stop its evolution, but the vision can not be restored when the disease is already evolved. "Early detection of glaucoma is, therefore, essential," recalls the National Institute of Health (INSERM), from the age of 40 to 45 years, or earlier in the case of myopia or a history of glaucoma in the family. The disease can occur at any age, including at birth, but affects 1 to 2% of the population over 40 years of age and about 10% after 70 years, according to Inserm figures.
200 screenings planned
More than one million people are concerned in France ", about 600,000 of whom are treated, while 400,000 are unaware of it," says Professor Philippe Denis, president of the SFG, quoted by AFP. To detect the disease, doctors measure the pressure of the eye with a forced air tonometer. A new ultrasound technique is available in some centers.
Too high a pressure is "a major risk factor but is not synonymous with glaucoma because one can develop one without high intraocular pressure," says Professor Denis. In this case, an ophthalmologist should be advised and a treatment based on eye drops may be prescribed to stabilize the disease. The "bus of glaucoma" is expected to perform about 200 screenings in the week according to the head of Unadev's ophthalmology health center, Thibaut Fourteau, reports AFP.
glaucoma: soon a contact lens that treats
American researchers have developed a contact lens capable of delivering the right dose of glaucoma medication directly into the eye. A pair of lenses may deliver the treatment for one month.
Researchers at the Department of Ophthalmology at the Boston Children's Hospital have developed a contact lens that will deliver controlled amounts of drug directly into the eyes of patients with glaucoma. Worn every day, these lenses will be able to deliver the treatment for one month.
Glaucoma is a disease of the optic nerve that reaches the visual field and increases eye pressure. This condition of the eye is treated initially with the aid of an eye drops instilled regularly in the eyes to reduce the pressure of the eye. But Dr. Joseph Ciolino, who led the research on this new type of contact lenses, said: "The drops that are instilled in the eyes require a good adherence to treatment on the part of the patient to be totally effective. However, patients often forget their eye drops voluntarily or not ".
For the physician, contact lenses have the advantage of delivering the drug without the patient having to think about it. And if the first trials have focused on glaucoma, this form of ocular drug delivery could help treat other pathologies.
These new lenses enclose under their plastic a thin film which contains the drug. The tests showed that after one month of wearing lenses, the concentration of drugs in the eye was identical to that of a month of treatment by eye drops. Another advantage: this treatment can be adapted to corrective lenses.
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glaucoma: how is it treated?
Glaucoma is a serious eye disease that affects nearly one million people in France. Difficult to detect in its beginnings, this pathology of vision must nevertheless be treated quickly. Eye drops, laser, surgery ... Current treatment of glaucoma with Dr. Ancel, the surgeon ophthalmologist.
glaucoma treatment
Summary
What is Glaucoma?
Treat glaucoma with eye drops
Curing Glaucoma with the Laser
To treat glaucoma through surgery
What is Glaucoma?
Glaucoma is a disease of vision that involves a progressive attack on the optic nerve and the visual field by an excessive rise in ocular pressure. This pathology, which must be taken very seriously, usually appears from the age of 45 years. Without treatment, it can lead to total loss of vision.
Difficult to detect in the absence of symptoms, glaucoma must be detected regularly in an ophthalmologist. We distinguish chronic glaucoma, which represents 90% of cases and acute glaucoma, much rarer. The causes of glaucoma remain mysterious but some risk factors exist age, heredity, severe myopia or high blood pressure and diabetes.
>> Discover also: Glaucoma: why should you think about screening?
Treat glaucoma with eye drops
The treatment of glaucoma depends on each case. Only your ophthalmologist can decide which one is right for you. Generally, the prescribed treatment is based on eye drops in the form of drops. Their purpose: to reduce the eye pressure in the eyes. The most effective treatment that stabilizes the disease but must be monitored daily (usually 1 to 2 times a day) and often for life. It is, therefore, a rather restrictive treatment.
When the prescribed eye drops are no longer effective or poorly tolerated (in the case of eye pain, allergy, fatigue ...) the ophthalmologist can propose to treat glaucoma by laser or by surgery.
>> To discover also: Sensitive eyes: how to choose the right mascara
The laser is a technique for the effective treatment of glaucoma. In the case of chronic glaucoma, the flow of the aqueous humor (intraocular fluid circulating from the back of the iris through the pupil to a region called the iridocorneal angle) is decreased. Increase the pressure. The laser makes it possible to widen the "mesh of the net" of the iridocorneal angle and thus facilitate the flow of the aqueous humor.
It may be necessary to repeat the laser sessions, the eye tension may tend to rise with time. In the case of acute glaucoma, the circulation of the aqueous humor is blocked at the pupil and the tension can rise sharply and significantly. A piercing of the iris laser (iridotomy, one session) then short-circuit the pupillary passage and thus lower the tension. The laser operation is painless. It takes place under simple local anesthesia and does not cause any scarring visible to the naked eye.
To treat glaucoma through surgery
In the case of failure with drug treatments but also when the laser proves to be ineffective, surgery should be considered. Glaucoma surgery is a very benign operation that reduces ocular pressure so that the disease does not evolve, by making a valve to facilitate the drainage of the aqueous humor outside the eye (under The conjunctiva). Unfortunately, in the case of glaucoma, what is lost is lost and the surgery does not allow to diminish or eliminate the alterations of the visual field, which will persist after the intervention. The operation is carried out under local or general anesthesia during a short-term hospital stay. The operation in itself generally lasts about thirty minutes.
With the collaboration of Dr. Jean Marc Ancel, Surgeon Ophthalmologist, Member of the Academy of Surgery and author of These Surgeries of the View that change the life at Mediasphere.
glaucoma: a new visual test to detect it
The Australians have just introduced a new eye test that would detect the risk of glaucoma several years before the onset of the disease.
Glaucoma: a new visual test to detect it
As the causes of glaucoma are not yet known, it is not yet known how to cure the disease. On the other hand, when glaucoma is detected early enough, it is possible to stop its development and prevent it from getting worse.
Unfortunately, like the noiseless disease, that is, without pain and without real symptoms, many patients are often diagnosed only when they have lost a large part of the sight. "Early detection is the key to the treatment of glaucoma. But most people who are affected are totally unaware of it. That's why glaucoma is called the sight thief, "says Professor Andrew Iwach of the San Francisco Glaucoma Center.
Also, many researchers are working today on the possibility of detecting the disease before it even declares itself. This is the case of Australian researchers who have just presented a test which makes it possible, based on measurements of eye tension of the retina, to detect people who are four times more likely to develop glaucoma after 45 years.
To achieve this test that has just been published in the professional magazine Ophthalmology, the researchers followed about 2500 adults over the age of 49 for 10 years. None of them suffered from glaucoma at the beginning of the study, but those who developed the disease had a higher eye pressure at the first tests than the others.
That is why researchers believe that the first screening tests should be carried out as early as 40 years and every two years thereafter. "Especially since these sight tests allow us
glaucoma: Are you at risk?
Glaucoma is characterized by progressive deterioration of the optic nerve. Half of the people affected by this disease are unaware of it. Are you concerned? Do you have to be screened?
glaucoma: Are you at risk?
More than one million French people would be affected by glaucoma. Management too late, this disease can lead to blindness. This is why screening is paramount.
Risk factors for glaucoma
Screening concerns more particularly open-angle glaucoma. The symptoms appear late, once the site is already reached, hence the importance of detecting it early. Warning signs are decreased peripheral vision, blurred vision of objects close to oneself, headache and eyesight.
People at risk are those who are over 40 years of age and have a family member who is already suffering from glaucoma and who are of African descent.
Some factors also increase the possibility of developing glaucoma: high blood pressure, frequent migraines, diabetes, taking corticosteroids. If you are short-sighted, your risk is multiplied by three.
How is screening done?
Una de (The National Union of the Blind and Visually Impaired) is launching this week a national campaign to prevent and detect risk factors for glaucoma. A bus equipped with state-of-the-art ophthalmic equipment moves from town to city with a specialist practitioner on board. During the consultation, people undergo three rapid and painless examinations: intraocular pressure measurement and corneal thickness measurement, fundus observation, visual field test.
The consultation sheet, provided at the end of the tests, allows you to make an emergency appointment with an ophthalmologist if you suspect glaucoma, at the local CHU or at one of the doctors recommended by The French Society of Glaucoma (SFG).
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