You can do more than glasses and are not completely satisfied with your lenses? Surgery remains ...
Or its alternative, yet very widespread in France but much more in Asia
and the United States: Orthokeratology or corneal reshaping.
Technology, and reversible for people slightly nearsighted and / or astigmatic , is to wear lenses overnight to change the curvature of the cornea and have corrected for the next day. Is it really effective? What are the risks and cons-indications? Why do not we hear more about? Dr. Phat Eam Lim, surgeon-ophthalmologist, is one of the few specialists in France to be able to adapt this type of lenses.
"There is no question to crush the cornea as we sometimes hear, says the specialist. During the day, the epithelial cells are renewed and returned to their original location where the reversibility of the correction. ' Seven hours of night wear, sometimes less, help maintain a visual acuity of 10/10 the next day or the next day for the weak corrections.
Having to wear their lenses while sleeping may seem surprising. For Dr. Lim is a plus: "The night hygiene are maximal. Moreover, orthokeratology lenses cover a small area and are very permeable to oxygen. The most important is sometimes allow the cornea to breathe. This is even better the day when it is free and tears easily remove dust and pollutants. "
Children and adolescents may also benefit from the technique. "There is no minimum age to wear contact lenses, said the doctor. However, the ideal is to wait until the child know how to respect hygiene precautions to put and remove the lenses only in general from 8-10 years. seems as orthokeratology allows to stabilize the myopia in children, an international study is underway to confirm this. "
Against the absolute contraindications are rare, they are mainly people with conditions affecting the surface of the cornea as corneal dystrophies, keratoconus (degeneration of the cornea) ... In case of insufficient tear or cornea already very flat, it is possible to test but the result is more random.
Fear, after years of use, is that the cornea deforms permanently. "After two years, we have shown that it does not move and, in countries that use the technique for more than fifteen years, there has been no particular problem, notes Dr Lim. Epithelium As only corneal undergoes changes and remain transient, we have every reason to believe that orthokeratology not induce complications. Nevertheless, it is true that we still lack long-term studies to ensure its total safety. '
As with any lens, especially the risk of infection. In the early 2000s, Chinese teams reported cases of corneal ulcers, particularly among children and adolescents. Specialists insist on hygiene for lenses but their cases and solutions to be renewed regularly. Parents should be particularly attentive to how proceed younger and consult at the slightest suspicious signs (redness, pain ...). Maladaptation can also irritate the cornea and increase the risk of infection.
"After ten or twenty years, it is possible that we will see some changes in the cornea, similar to those observed with ordinary lenses, but this has not been demonstrated," says Dr. Lim.
And measuring devices became more sophisticated. They can now offer lenses suited ensuring that they are well tolerated. Biocompatibility and permeability of the materials used in their manufacture have also increased. Orthokeratology, a time abandoned in favor of surgery is first returned to Asia and North America. In France, ophthalmologists are interested for only two or three years.
Dr. Lim attributed the delay in part to a conservative French: "The surgeons are ophthalmologists Orthokeratology quite logical since it reproduces transiently they get through the operation (keratectomy). However, lentils are not their specialty. ophthalmologists It is the contactologues-which, until recent years, were insensitive to the technique. "
According to Dr. Jean-Bernard Rottier, President of SNOF (National Union of ophthalmologists in France), there are fewer than twenty ophthalmologists able to adapt orthokeratology lenses, which makes the technique very accessible in practice. As Dr Lim, he observes, however, that there is growing interest in his fellow contactologues. The number of trained practitioners should increase rapidly. Remain in the list.
For their part, the labs are already mobilized. In France, in 2004, only provided Technolens orthokeratology lenses to European standards, Ortho-K. Today Precilens offers DreamLite and Menicon Z-Night. Research is underway to develop models that can also correct the farsightedness and presbyopia .
Technology, and reversible for people slightly nearsighted and / or astigmatic , is to wear lenses overnight to change the curvature of the cornea and have corrected for the next day. Is it really effective? What are the risks and cons-indications? Why do not we hear more about? Dr. Phat Eam Lim, surgeon-ophthalmologist, is one of the few specialists in France to be able to adapt this type of lenses.
How Orthokeratology?
Orthokeratology uses semi-rigid lenses whose inner face has a particular form: "It forces the cells of the epithelium, the outermost layer of the cornea, to position where we want during their natural migration from the periphery to the center, "said Dr Lim. The periphery thickens, thins the center ... In the end, over 5.5 mm in diameter, the surface of the cornea is less curved. Deeper cell layers are not modified."There is no question to crush the cornea as we sometimes hear, says the specialist. During the day, the epithelial cells are renewed and returned to their original location where the reversibility of the correction. ' Seven hours of night wear, sometimes less, help maintain a visual acuity of 10/10 the next day or the next day for the weak corrections.
Having to wear their lenses while sleeping may seem surprising. For Dr. Lim is a plus: "The night hygiene are maximal. Moreover, orthokeratology lenses cover a small area and are very permeable to oxygen. The most important is sometimes allow the cornea to breathe. This is even better the day when it is free and tears easily remove dust and pollutants. "
Who can benefit from orthokeratology lenses?
Orthokeratology lenses to correct myopia and astigmatism-4D up to -2.5 D, both at the same time if necessary. "They offer a real alternative to surgery for all those who wish to be released from their glasses or contact lenses during the day but do not want or can not be made, particularly in the case of cons-indication or if the view is not stabilized (myopia development, presbyopia beginner ...), says Dr Lim. Sometimes they can also be used when ordinary lenses have been deprecated. Sportsmen and professionals working in water or dust are particularly interested. " The specialist team of firefighters, rugby players, swimmers, surfers ... and pelota players, many in their area of practice.Children and adolescents may also benefit from the technique. "There is no minimum age to wear contact lenses, said the doctor. However, the ideal is to wait until the child know how to respect hygiene precautions to put and remove the lenses only in general from 8-10 years. seems as orthokeratology allows to stabilize the myopia in children, an international study is underway to confirm this. "
Against the absolute contraindications are rare, they are mainly people with conditions affecting the surface of the cornea as corneal dystrophies, keratoconus (degeneration of the cornea) ... In case of insufficient tear or cornea already very flat, it is possible to test but the result is more random.
What are the risks and side effects of orthokeratology?
Night, unless you have to get up frequently for activities requiring a correct view (taking care of an infant for example), the lenses are rarely troublesome. However, they can move, which disrupts the vision of day or night halos induce in people with large pupils.Fear, after years of use, is that the cornea deforms permanently. "After two years, we have shown that it does not move and, in countries that use the technique for more than fifteen years, there has been no particular problem, notes Dr Lim. Epithelium As only corneal undergoes changes and remain transient, we have every reason to believe that orthokeratology not induce complications. Nevertheless, it is true that we still lack long-term studies to ensure its total safety. '
As with any lens, especially the risk of infection. In the early 2000s, Chinese teams reported cases of corneal ulcers, particularly among children and adolescents. Specialists insist on hygiene for lenses but their cases and solutions to be renewed regularly. Parents should be particularly attentive to how proceed younger and consult at the slightest suspicious signs (redness, pain ...). Maladaptation can also irritate the cornea and increase the risk of infection.
"After ten or twenty years, it is possible that we will see some changes in the cornea, similar to those observed with ordinary lenses, but this has not been demonstrated," says Dr. Lim.
A method that is slow to develop
Orthokeratology has existed since the 1960s. Long, the technique was only available by opticians or other non-medical professionals. Ophthalmologists were particularly reserved especially as they did not yet know how to alter the cornea.And measuring devices became more sophisticated. They can now offer lenses suited ensuring that they are well tolerated. Biocompatibility and permeability of the materials used in their manufacture have also increased. Orthokeratology, a time abandoned in favor of surgery is first returned to Asia and North America. In France, ophthalmologists are interested for only two or three years.
Dr. Lim attributed the delay in part to a conservative French: "The surgeons are ophthalmologists Orthokeratology quite logical since it reproduces transiently they get through the operation (keratectomy). However, lentils are not their specialty. ophthalmologists It is the contactologues-which, until recent years, were insensitive to the technique. "
According to Dr. Jean-Bernard Rottier, President of SNOF (National Union of ophthalmologists in France), there are fewer than twenty ophthalmologists able to adapt orthokeratology lenses, which makes the technique very accessible in practice. As Dr Lim, he observes, however, that there is growing interest in his fellow contactologues. The number of trained practitioners should increase rapidly. Remain in the list.
For their part, the labs are already mobilized. In France, in 2004, only provided Technolens orthokeratology lenses to European standards, Ortho-K. Today Precilens offers DreamLite and Menicon Z-Night. Research is underway to develop models that can also correct the farsightedness and presbyopia .
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