Orthokeratology for Myopia Control

Ortho-K is one of the most effective tools available for treating myopia. Results in our practice show slowing, and in some cases even complete halting, of myopia progression.

Myopia — or shortsightedness — refers to poor distance vision but clear near vision. This happens when the eyeball grows too long in relation to the power of the eye’s lenses. The light rays then focus at a point in front of the retina, rather than directly on its surface. Myopia usually appears in childhood. The condition does run in families, but some children are becoming shortsighted even though their parents have no vision problems. That means genetics is not the only contributing factor.

The development of myopia seems to also be influenced by environmental factors, such as near work. Studies show that the more near work performed, the more likely your child will become nearsighted. In one study, boys in Orthodox Jewish schools were found to have a higher rate of myopia (81.3%) compared with boys in general Jewish schools (27.4%). The boys in the Orthodox schools spent upwards of 16 hours a day studying. Lack of time spent outdoors has also been implicated.

Myopia Prevalence

The increase in myopia cases is worryingly high across the world.

  • There are approximately 1.4 billion people worldwide with myopia
  • This is estimated to reach 2.5 billion by 2020
  • 93% of 18 year old girls in Taiwan are myopic
  • 7/10 college graduates in Singapore are myopic
  • Up to 78% of 15 year old girls in urban China are myopic

We have not missed out close to home, either:

  • In Australia, 30% of Australian school leavers are myopic — and this percentage is on the rise

Progression and Associated Risks

Adult-onset myopia (developing after 20 years of age) can progress over time, though youth-onset (before 20 years) generally shows more aggressive progression which continues until the eye stops growing. Typical sufferers are highly dependent on expensive, high-powered glasses or contact lenses and require frequent replacements as the condition escalates.

All levels of myopia increase the chance of these blinding conditions:

  • retinal detachment
  • cataracts
  • glaucoma
  • myopia retinal degeneration- later in life

These risks escalates as the level of myopia increases. Myopia maculopathy, a progressive condition causing holes in the retina due to over-stretching, is the fourth most common cause of visual impairment in the UK ahead of diabetic eye disease.

Studies show the risk factor for eye disease due to myopia is comparable to the risk of cardiovascular disease due to untreated high blood pressure. The risk for glaucoma and cataract due to myopia compares to the risk of stroke from smoking over 20 cigarettes per day. For retinal detachment and myopic maculopathy, myopia carries a risk far in excess of any identified population risk factor for cardiovascular disease. Given that higher levels of myopia entail a higher risk of these conditions, halting this progression can broadly prevent a significant level of blindness.

Treatment

Prescribing standard spectacle lenses or contact lenses will do nothing to halt the progression of myopia. The patient will require frequent lens updates and will be put at risk of sight-threatening problems in the future. The lengthening of the eye which causes myopia cannot be reversed, making it absolutely critical to control myopia sooner rather than later. The good news is, evidence shows that certain treatments can slow and even halt progression. Ortho-K is one of the most effective tools currently available for this purpose.

Ortho-K for Myopia Control

Research shows a 32%-100% slowing in the rate of myopia progression through using ortho-K; most reports suggest a 50% average. Results in our practice and others in Australasia show complete halting of myopia progression in some patients.

When myopic eyes are corrected with conventional spectacles and contact lenses, light entering the eye centrally will focus at the retina; however, light entering off centre will focus behind the retina. This is thought to stimulate lengthening at the back of the eye as the retina tries to reach the focal point behind the eye, worsening the condition. Ortho-K lenses can slow this growth by changing the shape of the eye surface, allowing central light to focus accurately at the retina and off-centre light to focus in front of the retina. The retina will no longer attempt to elongate.

Find out more about myopia control in children here.