What is Myopia?
Myopia (short-sightedness) is a result of an excessive elongation of the eye where light focuses in front of, instead of on, the retina. This causes distant objects to be blurry while close objects
appear normal. Recent studies have shown that the prevalence of myopia is on the increase (by over 70% in Asia & by up to 50% in the US & Europe).
Why Is It Important To Reduce How Myopic We Become?
The earlier the onset of myopia in an individual generally leads to higher level of myopia in later life which increases risk factors for several ocular pathologies including glaucoma, cataract, retinal
detachment, & myopic maculopathy brought about by the accompanying elongation of the eye. The highest risk is typically found in high myopia >-5.00DS. So, if we can reduce how myopic an individual ends up as an adult this will reduce their risk of developing certain pathologies in later life. A reduction in the final level of myopia by only 1 dioptre reduces the lifetime risk of macula degeneration by 40% and the risk of vision impairment by 20%.
Risk Factors For Myopia & Myopic Progression
- One or both parents being Myopic.
- Already being myopic (short-sighted).
- Being myopic at a young age.
What Can We Do To Try And Prevent Myopia And Its Progression?
Strong evidence exists that spending time outdoors (more than 2 hours per day) can protect against the onset of myopia and possibly reduce the final level of adult myopia. The total time spent outdoors appears to be the important factor, rather than the nature of the activity undertaken.
The association between near work and myopic progression has been evaluated in numerous studies and the outcomes were beyond doubt. Excessive accommodative demand caused by near work has been linked to myopic progression along with the resulting hyperopic blur. It is recommended to limit the time children are spent undertaking near visual tasks ie viewing mobile phones and tablets. Special spectacles incorporating a reading prescription can be prescribed if excessive near accommodation is found during an eye examination.
Spectacles And Contact Lenses
Recent theories & studies are now suggesting that one of the reasons for myopic progression is that conventional spectacles and contact lenses are such that whilst the central image formed on the retina is in focus, the peripheral image formed by these lens designs is behind the peripheral retina. It is thought this may promote elongation of the eye as it attempts to form an image on the peripheral retina. By prescribing optical corrections such as peripheral de-focus spectacles ( Essilor Stellest lens) and special contact lenses ( soft dailies & orthokeratology, ) we now have options to help slow myopic progression and improve outcomes for younger patients. Studies have looked at pharmacological intervention (such as the Atropine for treatment of Myopia Study) to reduce myopic progression but this option is not currently available in the UK. Single vision under correction was a popular option for myopia management but randomised clinical trials unequivocally have shown not only does this strategy not work but actually can cause progression of myopia therefore is not recommended as a myopia control strategy.
It is important to note that no one treatment can promise to stop myopia progression in children, only slow it down.
Recommended Available Interventions
Multifocal Or Bifocal Spectacle Lenses
This is a lens correction with a reading zone in the lower part of the lens that reduces accommodative effort which helps reduce myopic progression. Various studies show this type of correction can reduce the final level of adult myopia by approximately 11-46% especially for individuals with additional near vision focussing issues(1).
Peripheral De-Focus Spectacles
This is a lens which has special ringed zones in periphery which create a peripheral de-focus which reduces the stimulus for the eye to continue to elongate slowing myopic progression. Studies have shown this type of intervention can reduce myopic progression by up to 67% when worn 12 hours a day(2). The Essilor Stellest lens is a game changing innovation in the field of myopia control and is now available at the practice.
For more information visit: https://global.essilor.com/uk/products/stellest / https://www.hoyavision.com/uk/vision-products/miyosmart/
Multifocal Contact Lenses
This works by allowing a clear central image to be formed on the retina whilst reducing the peripheral hyperopic defocus that is typically found in myopic eyes. This reduces the elongation of the eye. Various studies show this type of correction can reduce the final level of adult myopia by approximately 30-50% (3). We are accredited to fit the MiSight Soft Daily myopia control lens at the practice.
For further information visit: https://misight.com
Orthokeratology lenses ( Ortho-K ) are rigid contact lenses that you sleep in which gently alter the shape of the cornea ( like braces on teeth) so on awakening you can see clearly for the day without the needs or contact lenses or spectacles. With regard to myopia control, this works by flattening the corneal curvature in such a way that creates peripheral hyperopic defocus which reduces the stimulus for the eye to elongate similar to the other methods of myopia control. Various studies have shown this type of correction can reduce the final level of adult myopia by approximately 32-63%(4).
For more information or to find out about our myopia management plans please contact the practice.
- Brien Holden Vision institute ( bhvi.org ) – Myopia Management
- Bao, J., Huang, Y., Li, X., Yang, A., Zhou, F., Wu, J., Wang, C., Li, Y., Lim, E.W., Spiegel, D.P., Drobe, B., Chen, H., 2022. Spectacle Lenses With Aspherical Lenslets for Myopia Control vs Single-Vision Spectacle Lenses: A Randomized Clinical Trial. JAMA Ophthalmol. 140(5), 472–478. https://doi.org/10.1001/jamaophthalmol.2022.0401.
- Optometry Today Volume 58:02 February 2018 – Myopia
- Review of Optometry July 2012 – Consider ortho K for myopia control