Lenses of the future: progress visibly

By making it possible to do without binoculars, lenses have already changed our life. They can be worn at night to reduce myopia when waking up (this is orthokeratology) or implant them in the eye to replace the lens during a cataract operation. But researchers see further and imagine them with many other functions.

Devices able to cure glaucoma

Not obvious to drop drops in the eyes ... Lenses could remedy the problem. " Being hydrophilic, they pick up liquids like sponges and can act as a reservoir of medicine to deliver them gradually Philippe Denis, head of the ophthalmology department at La Croix-Rousse hospital in Lyon (Rhône), explains. Research has been going on for several years on glaucoma, a disease in which too high intraocular pressure gradually destroys the optic nerve. A Harvard team is working on lenses incorporating a polymer to deliver an antiglaucoma drug (latanoprost) for a month, with positive results on monkeys ... it remains to be verified on humans. Last November, researchers in Singapore announced that they have developed a prototype with tiny, dissolvable needles that are used to deliver these molecules in multiple doses. They are now looking to make it as comfortable and painless as possible. " We know that with a drop of eyewash90% of the product disappeared from the surface of the eye after five minutes due to tears and eyelid movements. This type of device would increase the time of the drug on the eye and make the treatment more effective "Says Professor Denis, president of the French Society of Glaucoma. The same principle could be used to deliver antibiotics in case of eye infection.

A measurement of intraocular pressure for twenty-four hours

In order to better treat glaucoma, the Swiss company Sensimed has developed a lens to monitor intraocular pressure for twenty-four hours. In consultation, the ophthalmic measure but at a time T, for ten seconds only. Having a more complete picture of pressure changes during the day and at night would allow doctors to observe the course of the disease and better adjust treatments. Triggerfish®, this microsensor-equipped contact lens, measures changes in eye volume, based on the assumption that a change in eye pressure affects the curvature of the cornea. " It is interesting but not yet revolutionary because in reality these measurements give us one of the parameters to know but do not quite coincide with the measurements of the ocular pressure ", Nuance Professor Denis. Further research will help to determine what exact lessons can be learned. Meanwhile, this lens is already tested in some French hospitals and will be marketed very soon in Japan.

A dressing that resolves itself

Another track that pleases us: lenses in natural protein collagen, which would fall apart thanks to the lachrymal secretions after six hours to a week as needed. The goal? To fight against dry eye problems or temporarily protect an operated or injured area. Much more discreet than the pirate bandage! Of course, they could also be used to deliver drugs. Australian researchers have developed a formula that is supposed to boost the healing of the eye with cells from donor tissue (recovered from corneal transplants) and an amniotic membrane from the human placenta. According to their work, this lens helps fight against inflammation and releases interesting healing factors in case of corneal ulcers for example. Clinical trials must be performed on humans to confirm its therapeutic virtues.

A dye to correct color blindness

A process to no longer see the green half green only! This hope should delight the color-blind, who generally, poorly distinguish this color and red because of some cones deficient in their retina. Researchers at the University of Birmingham have therefore imagined a lens tinted with a dye (obviously nontoxic) that blocks a band of light. Eliminating this band prevents the triggering of the cones that hinder the differentiation of hues. According to their publication last April, color-blind participants find a more "normal" view. They may be more discreet to wear than the pink tinted glasses that already exist, because the color could melt with that of the iris, especially if it is dark. Above all, this dyeing method would have a low cost. Moreover, scientists are already considering other colors to compensate for the poor vision of blue and purple. Good news for these gentlemen especially, since 8% of men are color-blind, against only 0.5% of women.

Blood glucose control neither seen nor known

This is the Grail for all diabetics: knowing your blood sugar without having to think about it. Considered a few years ago, one solution is to use a soft lens capable of measuring the level of glucose continuously not in the blood but in the tears that moisten the cornea. The icing on the cake: it warns discreetly in case of abnormal result by a small led light in front of the eye and / or an alert on our smartphone. Google and Novartis, involved in the project, threw in the towel at the end of 2018, due to a lack of precision: measurements of glucose concentration in the blood and those in tears did not coincide. Diabetologists point out that the measurement is less reliable and especially less immediate than that in the blood. And wonder if a crisis of tears could dilute glucose and distort the numbers. But the idea is not buried yet! A team from South Korea has published encouraging data: in the lab, on a rabbit equipped with this soft lens that does not hinder vision (thanks to expandable and transparent electrodes), scientists say they have obtained reliable results. We are waiting for confirmation with tests on real diabetic patients before getting excited!

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