Ortho-K lenses deliver clear result on the touch field

Rodney College student Georgia Brierly has just returned from a touch competition in Europe, where she represented the NZ Barbarians U18 Girls Sevens team against club sides from Sweden and the Netherlands.

Conveniently Georgia has been able to ditch her glasses thanks to her orthokeratology (Ortho-K) lenses that correct her eyesight as she sleeps. Advances in Ortho-K, mean Georgia no longer has to wear glasses or contact lenses during the day.

Ortho-K involves gently reshaping the cornea of the eye to temporarily modify or eliminate refractive error - including short sightedness or myopia.

While the process has been practised for almost 40 years, results were quite variable and unpredictable. However, in the last 10 years new technology has become available to accurately map the corneal shape and manufacture lenses that will achieve a controlled and precise correction in the eye. In addition, new developments in lens materials have been made that enable safe overnight wear to be possible.

Optometrists fitting Ortho-K soon realised that young people wearing these lenses to correct short- sightedness didn’t progress or get worse like those who wore regular glasses or soft contact lenses. Numerous studies confirmed that wearing Ortho-K lenses stopped or slowed kids from getting more short-sighted.

“Rates of short-sightedness have been increasing worldwide; in the US rates of myopia (short-sightedness) have increased from 25 per cent to 42 per cent in 30 years and by 2050 it is predicted that 50 per cent of the population will be short-sighted, doubling what the rate was in 2000,” Claire McDonald says.

“Our concerns are also the more short-sighted you become, there is more risk your eyes will develop cataracts, retinal detachments, macular degeneration and glaucoma. So Ortho-K offers both short term and long term benefits”.

Ortho-k is now a safe, viable and reversible alternative to refractive surgery. The cornea, while being mouldable, will return to its original shape if lens wear is stopped.

“You simply sleep in your lenses, then wake up and remove them, and enjoy clear vision all day.”

Georgia said she enjoys playing touch while being able to see clearly without having to think about using corrective contact lenses, and her mum, Rachel, tells us “Ortho-K has changed Georgia’s life”.

Myopia Management - Resources

Short-sightedness is a global public health problem. Most people think of myopia (the medical term for short-sightedness) as an inconvenience because the blurred vision it causes is easily corrected with glasses or contact lenses. The problem is that a myopic eye is a longer eye and so the light sensitive part at the back of the eye is stretched. This can lead to a number of eye diseases in later life, such as glaucoma, maculopathy and retinal detachment. Higher levels of myopia (stronger glasses) correlates to greater problems.

Experts are also concerned because the number of people with myopia is increasing. Research suggests that by 2050 it will affect half the world’s population. Myopia normally develops in children and increases in prevalence and amount during the teenage years. We know that about 30% of teenagers in the UK have myopia, and in some East Asian countries around 80% of teenagers have myopia.

Here are the predictions: 

• 5 billion myopes by the year 2050; up from 1.4 billion in 2000
• 1 billion high myopes by 2050; a five-fold increase from 2000
• Number with vision loss from high myopia to increase seven-fold from 2000 to 2050; myopia to become a leading cause of permanent blindness worldwide.

The impact of these levels of myopia on all areas of society is enormous due to the cost of eye examinations, glasses and treatment of eye disease. The reasons why myopia develops are not fully understood; the prevalence has increased too quickly to be explained solely by genetics.

We know that our visual environment also has a role in myopia development. Our lifestyle has changed significantly over the last 50 years, with greater time being spent indoors on computers, tablets and smartphones. It is the lack of time that children spend outdoors that seems to trigger myopia development.

Globally there are many people actively looking for ways to prevent myopia, or, if it has started, at ways to slow its progression. It has challenged our traditional approach to myopia, test vision and make up stronger glasses as needed. Now we are actively helping people consider alternatives which may help reduce progression, and increasing understanding of this phenomenom.

Here are some resources:

Australian Optometrist Dr Kate Gifford has developed an online tool for families to work out the risk of children becoming myopic - My Kid's Vision

Myopia Prevention is a good overview.

Nature published this great article about the Myopia Boom.

Please contact us if you would like to discuss myopia. 

Myopia Management - Ortho-K

Managing Myopia

Myopia  (short sightedness) occurs when the eyeball is too long or too powerful resulting in blurred distance vision. People with myopia are unable to read the board at school, or need glasses for driving. Vision for near objects is clear, within a close range.  Once someone becomes myopic their vision tends to get worse over time and glasses and contact lenses become stronger. The greatest change is usually in childhood and teen years.

Why do we need to control myopia?
High levels of myopia are associated with increased risk of eye diseases such as glaucoma, cataracts, retinal detachment and macular degeneration later in life.

Can you (really) slow or stop myopia?
Yes! Most people can slow down or stop their eyes from becoming more myopic. This is exciting news which resonates with all parents who are short sighted.

What causes myopia development and progression? 
Genetics, individual characteristics and environment. 

In the last 10 years, there has been considerable research into finding the environmental factors which cause myopia progression. Much has been learned from work in animal models. Current understanding is the stimulus to axial elongation—and hence to myopia progression—is defocus not in the central retina but in the mid-periphery. In experimental models, peripheral focus has emerged as very important.

Optometrists can help reduce progression of myopia. We evaluate the whole clinical picture, measuring vision and prescription, recording family history, understanding reading habits and outdoor activity. There are different options to correct vision. Research shows us how each option will influence myopia development. We can intervene and hopefully stabilize vision changes

Techniques include progressive/bifocal glasses with reading power, multifocal soft contact lens, prescription eye drops and Ortho-K contact lenses to reshape the eye. When we have completed an eye examination we can discuss each of these options in full.

Orthokeratology (Ortho-K)

Ortho-K is the use of specially designed rigid contact lenses worn overnight. The contact lens gently reshapes the cornea giving clear vision the following day without contact lenses or glasses. The effect of the lenses is temporary, giving  a day of clear vision and lenses need to be worn every night. (If the lenses are not worn at night, vision will be blurred again the next day).

Overnight Ortho-K lenses produce a corneal shape that seems to be ideal for preventing axial length progression. Ortho-K makes use of “reverse geometry” lenses that are relatively flat in the center. Wearing these lenses at night causes the cornea to become temporarily flat centrally and a little steeper in the mid-periphery. As a result, the Ortho-K produces focused central and mid-peripheral images, which is useful for myopia control.

Although RGP lenses are not known for being comfortable, Ortho-K lenses are worn only at night when sleeping, so there is no discomfort from lens-lid interaction. These are large lenses that don’t move on the eye and provoke sensation. In addition, the materials used are highly oxygen permeable.

Ortho-K is very satisfying for the practitioner. For many children, getting out of glasses gives a big boost to self-esteem; and their parents are thankful to be doing something positive for their children by reducing their myopic progression. Among kids who are active, Ortho-K is safer than glasses for contact sports and safer than ordinary contact lenses for swimmers. Myopia control is just one of many positive benefits of Ortho-K.