Myopia management message part 2 - efficacy

Let’s cut to the chase - until further notice, you can consider low dose (0.05%) atropine, soft multifocal CL's and OrthoK as all quite similar in terms of their myopia control efficacy, being around 50% on average. A network meta-analysis of sixteen different interventions studied for myopia control showed these options to all have similar efficacy when their refractive and axial length outcomes were put on a level playing field.¹

Here’s a little more detail to back up this simple message on efficacy. Usually we see studies presented as percentage rates of refractive or axial length control – percentage rates are influenced by the study design and features of the control group (eg. age, level of myopia, ethnicity) making it difficult to directly compare studies on the percentage rate alone. For this reason, meta-analyses provide the best indication. In the aforementioned meta-analysis,¹ instead of using percentages, the authors grouped the interventions by ineffective, weak, moderate and strong efficacy for both refractive and axial length outcomes. Strong efficacy (mean reduction of progression by >0.50D/year) was achieved by 0.1% to 1% atropine (not including rebound effects) while moderate efficacy (0.25 to 0.50D/year) was used to describe OrthoK, multifocal and novel soft contact lens designs and lower dosages of atropine. More recently, the difference between 0.01%, 0.025% and 0.05% atropine has been determined, with the LAMP study showing that 0.01% likely has minimal influence on axial elongation. You can read more about this in our blog Atropine - wonder or weak treatment?

These findings allow you to simplify the myopia management efficacy message to parents - generally, we can expect around 50% efficacy from each of these three options. In this way, you can consider firstly offering a contact lens correction to the progressing myope, and know that a similar myopia management result is likely to be achieved independent of the practitioner's access to or experience with each of the treatments. Wide availability of distance centred multifocal soft lenses (eg. Coopervision Biofinity or Proclear D lens) means that any practitioner has ready access to a myopia control tool, which also corrects ametropia, to offer to progressing myopic patients. Increasing uptake of paediatric OrthoK² and availability of daily disposable myopia control soft lens designs such as Coopervision's Misight (in Australia and the UK) and Visioneering Technologies' NaturalVue (in the USA) will see more tools added to the armament for many practitioners in the near future.

If the child in your chair is not yet willing or suitable for contact lens wear, and exhibits specific binocular vision disorders - esophoria and accommodative lag - then progressive addition or bifocal spectacles do show clinically useful effects of around 33% efficacy on average.^{1, 3} Atropine could be considered as a first line treatment in these children, however parents can suffer misconceptions that atropine will also correct ametropia, so you should firstly aim to correct the ametropia in such a way that will also help to manage myopia (contact lens options or progressive spectacle lenses, if suitable) and then add atropine if sufficient myopia control is not achieved, or if there is evidence or risk of faster progression. There is early research evidence that atropine and optical corrections may have an additive effect for myopia control, by mechanism of choroidal thinning and thickening⁴ - while studies are underway, this is yet to be confirmed in clinically applicable studies and when using the clinically typical 0.01% concentration. Side effects of atropine treatment should also be considered whereby a near add or photochromatic spectacle lenses may be required.

New research into spectacle lens treatments may see us prescribing novel designs in future which show results closer to the contact lens options - an award winning new spectacle lens designed at Hong Kong Polytechnic University is just around the corner!

In practice, this message of 50% efficacy means that a child will likely still progress under any of these treatments - and it is important for parents to have these realistic expectations of treatment - but progression will likely be at half the rate of an average, similarly aged child in a single vision correction. How a 50% treatment goal looks, per year, depends on the child's age. Which treatments you offer will depend primarily on what you have available, but you can be assured that with access to one of OrthoK, multifocal or myopia controlling soft contact lenses, or low dose atropine, you can provide evidence based myopia management. Spectacles are also a valid option too, for suitable children. If you're lucky enough to have access to all of them, which should you choose? Have a look at Selecting a treatment - decision trees to find out more.