Why isn’t the myopia control strategy working?

It’s important to note that there’s nothing currently available which can promise to STOP myopia progression in children. The current research and available options work to SLOW DOWN myopia progression - read more about efficacy in myopia management here. So if you’re seeing a change of -0.25 to -0.50D a year? Reassure yourself and your patient that this is expected. Sometimes however, a patient is progressing faster than they should be. Why is it occurring? And what can you do? Here's an investigation of why your myopia control strategy may not be working.

Non-compliance

In the case of atropine, the likelihood of non-compliance must be considered. A study of glaucoma patients (who knew they were being monitored for compliance!) showed only 50% of patients took their medication correctly 75% of the time.1 It could be expected that there would be better compliance when parents are monitoring children, but be wary of children being responsible for their own drops. Practitioners have lots of tricks and tips for helping patients remember drops (sticky-tape them to your toothbrush!) however questioning patients on the reality of their regime may simply indicate that if they improve compliance, their myopia control results may improve too. This same issue goes for orthokeratology, multifocal or myopia controlling contact lens and spectacle options - if not worn to your directed schedule the treatment won’t work as expected, especially if a child is spending significant time under-corrected.

In the case of non-compliance, it's important to have a collaborative discussion with the parent and patient to ensure that this treatment is still suitable for them. Non-compliance could point to issues with atropine side effects, contact lens comfort or spectacle lens adaptation, for example. Have a discussion to explore non-compliance, to gain consensus on the why and how of the planned myopia management strategy.

User error

Perhaps your patient and their parent implore compliance, but the child is blinking out the atropine drop after application. Perhaps the child is having breaks from their treatment over the weekend or school holidays, leading to long periods of under- or uncorrection. Perhaps they're not wearing their orthokeratology lenses for long enough each night and you're measuring and under-treatment more so than actual myopia progression. Investigate each aspect of the treatment process to ensure issues like these don't impede success.

Binocular vision

Myopes tend to be lousy accommodators. Myopic children have been shown to accommodative insufficiently to blur induced by negative lenses2 and a correlation between reduced accommodative response and myopia progression has been found.3 This reduced accommodative response (higher lag) has been shown to be related to faster myopia progression when wearing single vision spectacles, and a better myopia control response to progressive addition spectacle lenses.4

New data has shown similar in multifocal contact lenses (MFCL). A test MFCL design was found to reduce accommodative response, and this reduced response was correlated with a reduced myopia control effect. Interestingly, this relationship wasn’t found in the single vision distance CL corrected control group,5 indicating a complex interaction between MFCL optics and accommodation specifically.

A large accommodative lag can influence visual comfort and even contact-lens associated dry eye symptoms.Synthesising the studies above indicates that a large accommodative lag could also be influencing your myopia control treatment success. For help on assessing and managing binocular vision check out our free resources in the Expand my Clinical Skills portal of this website; if you really want to get serious about BV, check out our comprehensive, six-hour online course Binocular Vision Fundamentals. The first hour of the course is available as a free preview.

High myopia

Almost all myopia control studies are undertaken on children aged 6-14 years of age, with myopia of -1.00 to -5.00D. Studies also typically exclude children with significant binocular vision disorders, amblyopia and/or strabismus. If the patient in your chair doesn't fit this criteria, then the typical or average results can't be assumed to apply.

Managing childhood myopia over 5-6D requires extra special care. In a clinical ophthalmology study of 112 children under age 10 with myopia of more than 6D, only 8% had 'simple high myopia' with no other associated ocular or systemic associations. 54% had an underlying systemic condition (eg. developmental delays, Marfan, Stickler, Downs syndrome) and the remaining 38% had further ocular problems associated with high myopia such as lens subluxation, coloboma, retinal dystrophy).

This means that in children under 10 with high myopia, involvement of paediatric ophthalmology - even as a single referral at minimum - is important to rule out underlying ocular pathology or systemic conditions. Consider co-management with ophthalmology, depending on your scope of practice. Remember though, that primary eye care / optometry is best placed to manage the vision of these patients in the long term, and being the primary myopia 'case manager'. Read an interesting case study on managing the very high childhood myope here.

It's imperative to explain this to parents of highly myopic children at the outset of treatment. Fast progression may still occur despite your best efforts, and it's impossible to know what the progression would have been without myopia control intervention. The key message here is that doing anything to actively manage myopia is likely better than a single vision correction, but that we have no research outcomes to guide us in what to expect of the results.

Visual environment

The picture of how outdoor time and screen time influences myopia progression is becoming clearer. Increased outdoor time, greater near work distance (more than 30cm) and taking breaks from near work every 30 minutes have been shown protective against myopia progression, although each by only around 0.25D over two years on average.8

A survey which analyzed data usage on smartphone devices found that myopic children and teens used almost double the amount of data compared to non-myopes.9 While this doesn't prove causation, the association is noteworthy.

Discuss visual environment with parents and patients as a key controllable factor in their overall myopia management success. For resources to provide to parents and patients, the MyKidsVision.org website includes a blog and How-To video guides - key references include:

Non-responders

Non-responders are those children who have shown minimal efficacy of their treatment in myopia control studies. By simple virtue of having an 'average' efficacy for a myopia control treatment, there will be some children who fall below and above that average. Influential factors are younger age, higher myopia, and higher prior myopia progression. Read all about the percentage of non-responders in key myopia control intervention studies in our blog entitled Non-Responders To Myopia Control Treatments.

What should you do?

  • Evaluate expectations. Consider whether the child in your chair is an 'average' myope likely to experience 'average' efficacy with their intervention strategy. Are they younger, a higher myope, a faster prior progressor, an amblyope? The usual results may not apply.
  • Revisit the treatment. This includes covering compliance and treatment process (user error) issues, as well as ensuring it is still a suitable treatment for that child's and their family's capabilities. If there as a treatment available that is known to work better - for example changing from progressive addition spectacle lenses to myopia controlling contact lenses - then consider changing treatments. Remember that comprehensive myopia management includes discussion of visual environment, so consider this part of the 'treatment' as well.
  • Add atropine. There are early studies showing a potential synergistic effect of atropine 0.01% and orthokeratology.10 Baseline data has been presented on atropine 0.01% plus multifocal contact lenses (Biofinity centre distance +2.50 Add) indicating good short-term tolerance of combination treatment, with data on efficacy to follow.11
  • Review more frequently. This can be especially helpful in cases of non-compliance and user error. Consider reviewing every 3-6 months if you were doing so at longer intervals before.
  • Remember that some progression will occur. In children under 10, around 0.25 to 0.50D per year of progression represents a great treatment outcome, compared to the 0.75-1.25D of annual progression likely in single vision wear. In children over 10, 0.50D per year or more of progression likely represents a non-response to myopia control treatment. For more help on gauging success specific to a child's age and treatment type, including communicating this to parents and patients, check out our blog on Gauging Success in Myopia Management and our Managing Myopia Guidelines - Clinical Practice Infographic and Parent Brochures.
Kate profile thumbnail

About Kate

Dr Kate Gifford is a clinical optometrist, researcher, peer educator and professional leader from Brisbane, Australia, and a co-founder of Myopia Profile.

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.

References

  1. Okeke, C. O. et al. Adherence with Topical Glaucoma Medication Monitored Electronically: The Travatan Dosing Aid Study. Ophthalmology 116, 191-199, doi:https://doi.org/10.1016/j.ophtha.2008.09.004 (2009) (link)
  2. Gwiazda J, Thorn F, Bauer J, Held R. Myopic children show insufficient accommodative response to blur. Invest Ophthalmol Vis Sci. 1993;34(3):690-4.
  3. Gwiazda J, Bauer J, Thorn F, Held R. A dynamic relationship between myopia and blur-driven accommodation in school-aged children. Vision Res. 1995;35:1299-304.
  4. Gwiazda JE, Hyman L, Norton TT, Hussein MEM, Marsh-Tootle W, Manny R, et al. Accommodation and related risk factors associated with myopia progression and their interaction with treatment in COMET children. Invest Ophthalmol Vis Sci. 2004;45:2143-51.
  5. Cheng X, Xu J, Brennan NA. Accommodation and its role in myopia progression and control with soft contact lenses. Ophthalmic Physiol Opt. 2019;39(3):162-71.
  6. Rueff EM, King-Smith PE, Bailey MD. Can Binocular Vision Disorders Contribute to Contact Lens Discomfort? Optom Vis Sci. 2015;92:e214-221. (link)
  7. Marr JE, Halliwell-Ewen J, Fisher B, Soler L, Ainsworth JR. Associations of high myopia in childhood. Eye. 2001;15(1):70-4 (link)
  8. Huang PHsiao YTsai C, 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
  9. McCrann, S., Loughman, J., Butler, J.S., Paudel, N. and Flitcroft, D.I. (2020), Smartphone use as a possible risk factor for myopia. Clin Exp Optom. doi:10.1111/cxo.13092 (link)
  10. Tan Q, Ng AL, Cheng GP, Woo VC, Cho P. Combined atropine with orthokeratology for myopia control: study design and preliminary results. Curr Eye Res. 2019 Jun 3;44(6):671-8 (link)
  11. Huang J, Mutti DO, Jones-Jordan LA, Walline JJ. Bifocal & Atropine in Myopia Study: Baseline Data and Methods. Optom Vis Sci. 2019 May 1;96(5):335-44 (link)

Leave a comment