Prescribing for the Progressing Myope with Astigmatism

Whilst each individual child has their own circumstances and situation to consider when prescribing myopia control, children with astigmatism present a unique set of challenges when selecting the best option for not only slowing down the progression of their axial growth, but also providing them with good vision. Simply ignoring the astigmatism when selecting a prescribing choice runs the risk of undercorrection, which can promote myopia progression.1

Orthokeratology (OrthoK)

Orthok has been shown to slow down the progression of myopia in school age children and is one of the most effective myopia control options.2, 3 Spherical orthokeratology can easily treat up to  -1.50D of astigmatism without specialised fitting.4, 5 Some OrthoK astigmatic lens designs can correct up to -4.00D of Astigmatism, providing excellent outcomes both refractively and as a treatment option for patients.4, 6 For more information on Orthokeratology, please read Orthok for Myopia control, the SMART Study post, or do our Myopia Management in Practice Course.

Multifocal Soft Contact Lenses

Multifocal soft contact lenses with a distance centre such as CooperVision's MiSight lenses may still be tolerated in low levels of astigmatism (<-0.75 to -1.00DC) and should be trialled for measured visual acuity whilst wearing the lenses. In patients with higher levels of astigmatism who are very keen on MiSight, spectacle correction with the residual astigmatism correction may be used, however compliance may be difficult in these patients.

Other designs of multifocal soft lenses such as Visioneering Technologies NaturalVue may mask further astigmatism. NaturalVue has been advertised as being able to be worn by some patients with up to -2.00DC, however the fitting guide recommends patients have astigmatism of -1.00DC or less. This provides another centre distance, daily disposable multifocal option for vision correction and myopia control.

Multifocal soft toric lenses with a centre distance modality are uncommon, and for most countries, only available in a monthly wearing schedule, which does slightly increase the (unlikely) risk of contact lens-related infections in children (for more information on this please read contact lens safety in children). CooperVision Proclear Toric Multifocal offers this option up to a -5.75 cyl with a range of ADD powers to +4.00. Another option is Mark'ennovy Toric Multifocal lenses, available in hydrogel and silicon hydrogel, custom made monthly designs.

Atropine Drops

Atropine Drops may be suitable in children who do not tolerate contact lenses or who have high levels of astigmatism. As glasses are worn full time (to minimise undercorrection) during atropine treatment to provide clear vision, astigmatism can be treated as per normal refractive correction. The LAMP study 2018 is now recommending percentages of/greater than 0.025% dosage for atropine control. However this may depend on the child, the level of side effects that occur and the level of axial length control achieved at different concentrations.7

Bifocal Glasses or Progressive Lenses

We know that single vision lenses do not provide any form of myopia control for children,8 however in children with binocular vision issues such as esophoria at near or accommodation lag, there is reasonable evidence that progressive lenses or bifocal lenses will slow the progression of myopia.9,10 The level of Add used however, needs to be tailored to the child’s near requirements, as too much or little can cause negative effects on their myopic progression. See the blog post “Prescribing Adds for Near Esophoria” and “Spectacle Lenses for Myopia Control – 1” for more information on choosing the correct spectacle lens add for your patient.

Doing Something

Every dioptre counts in myopia management. It's been shown that a 1D reduction in myopia reduces the risk of myopic maculopathy by 40%,11 and astigmatism is very commonly found with myopia.12 Using a myopia control strategy to reduce the end myopia result by even a small amount can reduce the end pathology results for your patient immensely, and is worth the extra effort to work around their astigmatism.

Cassandra Haines BIO image 2019_white background

About Cassandra

Cassandra Haines is a clinical optometrist, researcher and writer with a background in policy and advocacy from Adelaide, Australia. She has a keen interest in children's vision and myopia control.

This educational content is brought to you thanks to unrestricted educational grant from

References

  1. Chung K, Mohidin N, O'Leary DJ. Undercorrection of myopia enhances rather than inhibits myopia progression. Vision research. 2002;42(22):2555-9.
  2. Si JK, Tang K, Bi HS, Guo DD, Guo JG, Wang XR. Orthokeratology for myopia control: a meta-analysis. Optometry and vision science : official publication of the American Academy of Optometry. 2015;92(3):252-7.
  3. Davis R. Stabilizing Myopia by Accelerating Reshaping Technique (SMART)-Study Three Year Outcomes and Overview. Advances in Ophthalmology & Visual System. 2015;2.
  4. Baertschi M, Wyss M. Correction of high amounts of astigmatism through orthokeratology. A case report. Journal of Optometry. 2010;3(4):182-4.
  5. Chen C, Cheung SW, Cho P. Myopia Control Using Toric Orthokeratology (TO-SEE Study). Investigative ophthalmology & visual science. 2013;54(10):6510-7.
  6. Chen C, Cho P. Toric orthokeratology for high myopic and astigmatic subjects for myopic control. Clinical and Experimental Optometry. 2012;95(1):103-8.
  7. Yam JC, Jiang Y, Tang SM, Law AKP, Chan JJ, Wong E, et al. Low-Concentration Atropine for Myopia Progression (LAMP) Study: A Randomized, Double-Blinded, Placebo-Controlled Trial of 0.05%, 0.025%, and 0.01% Atropine Eye Drops in Myopia Control. Ophthalmology. 2019;126(1):113-24.
  8. Donovan L, Sankaridurg P, Ho A, Naduvilath T, Smith EL, 3rd, Holden BA. Myopia progression rates in urban children wearing single-vision spectacles. Optometry and vision science : official publication of the American Academy of Optometry. 2012;89(1):27-32.
  9. Cheng D, Woo GC, Schmid KL. Bifocal lens control of myopic progression in children. Clinical & experimental optometry. 2011;94(1):24-32.
  10. Gwiazda J, Hyman L, Hussein M, Everett D, Norton TT, Kurtz D, et al. A Randomized Clinical Trial of Progressive Addition Lenses versus Single Vision Lenses on the Progression of Myopia in Children. Investigative ophthalmology & visual science. 2003;44(4):1492-500.
  11. Bullimore MA, Brennan NA. Myopia Control: Why Each Diopter Matters. Optometry and vision science : official publication of the American Academy of Optometry. 2019;96(6):463-5.
  12. Huynh SC, Kifley A, Rose KA, Morgan IG, Mitchell P. Astigmatism in 12-Year-Old Australian Children: Comparisons with a 6-Year-Old Population. Investigative ophthalmology & visual science. 2007;48(1):73-82.