How does Ortho-K slow or stop your eyes from getting worse?
New research indicates that one of the causes for the progression of shortsightedness is peripheral retinal blur. This new theory states that while glasses and daytime contact lenses focus the central vision, they do not focus the peripheral vision very well. While the visual system is still developing (up to age in early 20s), the eye grows to try to improve focussing. The amount of growth of the eye is detetermined by the clarity perceived in the peripheral retina. With glasses the peripheral retina is blurred, since only the central retina is focussed correctly. This results in excessive growth of the eye and further progression of shortsightedness in people prone to this.
Ortho-K lenses reshape the front surface of the eye to form the correct shape for clear focussing onto both the peripheral and the central retina. Glasses and normal contact lenses cannot do this. For this reason it is believed that the progression of shortsightedness is slowed by using orthokeratology.
It can be frustrating for myopic people of all ages and optometrists alike to observe the progression of shortsightedness worsen at every consultation.
Can Orthokeratology Make a Long-Term Difference to Children's Vision?It has been shown that children and adolescents who have had Ortho-K, have a similar amount of myopia when they cease ortho-k to when they started it, even if they have been doing ortho-k for a few years. Comparably, this is different to the regular progression of shortsightedness, which tends to get significantly worse as children and adolescents get older.
Significant myopia progression can be prevented by performing ortho-k during the ages when the fastest progression is occuring. When ceasing Ortho-K, the original myopia will return, but it will not be much worse than the initial amount of shortsightedness. Ortho-K is an alternative method to try to stop or slow myopia progression in children.
The aim would be to do ortho-k until the age when myopia progression has become insignificant. Some people may continue ortho-k after this as a means of vision correction.
For example a child with a prescription of -1.75 when they start orthok may have the same or similar prescription four years later when they discontinue Orthokeratology. The myopia may then continue to progress at a normal rate for the age and the person, but at a much slower rate because of the older age.
Is Ortho-k like braces for the eyes?Orthokeratology is sometimes referred to as braces for the eyes. This is partially correct as the lenses do change the surface shape of the front of the eye. However, the change with orthodontic braces for teeth is permanent, whereas it is reversible with ortho-k. Also, braces are painfull whereas ortho-k is not.
Is OrthoK like wearing tight shoes?Practitioners who do not perform ortho-k sometimes give the incorrect analogy that the slowing of myopia progression with ortho-k is like wearing tight shoes to stop the feet from growing. This is incorrect as lenses placed at the front of the eye cannot physically stop the whole eye from growing longer. Therefore, this is not a correct representation of how ortho-k works to reduce myopia progression or as an alternative to refractive surgery or LASIK.
Advantages of Ortho-k for Children:
- No more worries about their child's vision in the classroom, particularly if they don't wear their glasses or are worried about losing a contact lens.
- No more worries about the loss of their childs glasses or contacts during sports.
- Fewer worries means a more positive attitude and self-image for their child.
- Ortho-K may stop or slow the progression of myopia (shortsightedness)