Myopia

Child wearing glasses

Myopia (Short-sightedness) Prevalence

The prevalence of myopia in young people has doubled worldwide in the last 50 years (ref. 1-3) but the good news is that we now have evidence-based options to reduce progression while it is changing during childhood, rather than just correct the refractive error. Myopia management does not cure or reduce myopia but aims to slow down the rate at which it gets worse.

To decide if the young person is at risk of rapid progression we can look at recent changes in prescription, family history and age of onset.(4)  Websites can help predict if child likely to develop high myopia using these various factors https://myopia.care/index

The toll of myopia

In addition to an extra reliance on optical correction, progressing myopia increases the risk of eye disease. Compared to emmetropes, patients with even 1 dioptre of myopia face an increased lifetime risk of developing glaucoma, posterior subcapsular cataracts, retinal detachment and macular degeneration.(5) Stronger spectacles are also heavier and more expensive.

Options for prevention and correction

Professionally researched studies have shown that there are interventions that can be used to reduce the progression in short-sightedness, and therefore the severity of the final level of myopia.

Behavioural change

The chances of a child becoming myopic are reduced by approximately 30% if the child spends more than 14 daytime hours a week outdoors.(6) Close work should be held at a greater distance than 30 cm and children should take regular breaks from near tasks out of school.(7)

Pharmaceutical treatment

Atropine has been shown to significantly control myopia progression when administered at 0.01%. Unfortunately the drug is not without side effects and at present, is not available yet in the UK, except as part of research trials.(8)

Spectacle lenses

In March 2021, MiyoSmart became available in UK.  These spectacle lenses use DIMS technology (Defocus Incorporated Multiple Segments) to reduce the peripheral retinal drive for increasing myopia. Research shows these lenses reduce myopia progression by 52%.(9)  There is some evidence that for certain progressing myopes (with a condition called esophoria and accommodative lag), spectacles with bifocal or progressive lenses can reduce the progression of myopia by 38–47%.(10)

Although it is intuitive to think it, the evidence for under correcting a child’s myopia (i.e. giving a lower prescription than they theoretically need) actually indicates that the myopia progression increases.(11)

Contact lens control

Soft multifocal lenses have been shown to significantly slow the progression of myopia.(12) The MiSight Dual Focus 1 Day contact lens has been shown to reduce the progression of myopia by an average of 59% over three years in 8 to 16 year olds.(13, 14). These lenses can also be worn alongside the MiyoSmart spectacle lenses, reducing the pressure on the child to wear contact lenses at all times. Ethnicity not a factor in MiSight effectiveness.(14)  Click here to download more information about the MiSight 1 Day Contact Lens.

Orthokeratology uses rigid contact lenses to change the shape of the front of the eye and are worn overnight. We have concerns on long term effect of remodelling cornea and problems with rebound effect so do not fit them at Morgan Optometry but can refer to another practitioner if this is your preferred option.

Of course, wearing contact lenses can pose challenges for paediatric patients, and each youngster’s ability to maintain proper hygiene and compliance habits must be thoughtfully assessed.


References
  1. Vitale S, Sperduto RD, Ferris FL, 3rd. Increased prevalence of myopia in the United States between 1971-1972 and 1999-2004. Arch Ophthalmol. 2009;127(12):1632-9.
  2. Logan NS, Davies LN, Mallen EA, Gilmartin B. Ametropia and ocular biometry in a U.K. university student population. Optom Vis Sci. 2005;82(4):261-6.
  3. Guo YH, Lin HY, Lin LL, Cheng CY. Self-reported myopia in Taiwan: 2005 Taiwan National Health Interview Survey. Eye (London, England). 2012;26(5):684-9.
  4. Brennan NA, Toubouti YM, Cheng X, Bullimore MA. Efficacy in myopia control. Prog Retin Eye Res. 2020:100923.
  5. Flitcroft DI. The complex interactions of retinal, optical and environmental factors in myopia aetiology. Prog Retin Eye Res. 2012;31(6):622-60.
  6. Rose KA, Morgan IG, Ip J, Kifley A, Huynh S, Smith W, et al. Outdoor activity reduces the prevalence of myopia in children. Ophthalmology. 2008;115(8):1279-85.
  7. Huang PC, Hsiao YC, Tsai CY, Tsai DC, Chen CW, Hsu CC, et al. Protective behaviours of near work and time outdoors in myopia prevalence and progression in myopic children: a 2-year prospective population study. Br J Ophthalmol. 2020;104(7):956-61.
  8. Chia A, Lu QS, Tan D. Five-Year Clinical Trial on Atropine for the Treatment of Myopia 2: Myopia Control with Atropine 0.01% Eyedrops. Ophthalmology. 2016;123(2):391-9.
  9. Lam CSY, Tang WC, Tse DY, Lee RPK, Chun RKM, Hasegawa K, et al. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial. Br J Ophthalmol. 2020;104(3):363-8.
  10. Yang Z, Lan W, Ge J, Liu W, Chen X, Chen L, et al. The effectiveness of progressive addition lenses on the progression of myopia in Chinese children. Ophthalmic Physiol Opt. 2009;29(1):41-8.
  11. Chung K, Mohidin N, O’Leary DJ. Undercorrection of myopia enhances rather than inhibits myopia progression. Vision Res. 2002;42(22):2555-9.
  12. Walline JJ, Greiner KL, McVey ME, Jones-Jordan LA. Multifocal contact lens myopia control. Optom Vis Sci. 2013;90(11):1207-14.
  13. Chamberlain P, Peixoto-de-Matos SC, Logan NS, Ngo C, Jones D, Young G. A 3-year Randomized Clinical Trial of MiSight Lenses for Myopia Control. Optom Vis Sci. 2019;96(8):556-67.
  14. Anstice NS, Phillips JR. Effect of dual-focus soft contact lens wear on axial myopia progression in children. Ophthalmology. 2011;118(6):1152-61.