Myopia Control: A Dynamic Field

Epidemiological studies show an increasing rate of myopia in European populations (1). Although genetic factors play a role in myopia pathogenesis, the recent increase in myopia prevalence worldwide has been attributed to environmental factors, including increasing intensity and duration of education, and global trends related to increased screen time for young children, especially from close distance, especially closer than 30 cm. Indeed, the main risk factors for myopia in children include more near work or near distance activities at a young age – as well as spending less time outdoors and having myopic parents. The major concern related to myopia is that up to 10 percent of children will develop high myopia, a serious risk factor for vision loss related with myopia, macular degeneration, and some serious eye disorders, including retinal detachment, glaucoma, and cataract.

An individual’s risk of developing myopic maculopathy, retinal detachment, posterior subcapsular cataract, and open-angle glaucoma all increase – by 58 percent, 30 percent, 21 percent and 20 percent respectively – with each additional diopter of myopia. Additionally, children with myopia are also at higher risk of developing depression compared with normally sighted children. Thus, increasing awareness of myopia prevention and controlling myopia progression strategies are becoming more important focuses in our routine ophthalmology practice across Europe. Fortunately, with increasing knowledge about myopia pathophysiology and risk factors, we have more approaches available to control myopia progression. In fact, every year studies presenting new approaches on myopia control are published, giving us an increasing number of options. On the other hand, because of this “dynamic situation,” the majority of review articles on this topic published over two years ago are outdated, so staying up to date is becoming more and more difficult. 

To that end, we decided to conduct a few analyses, which were recently published (2, 3, 4). The evidence from recent randomized control trials (RCTs) led us to some interesting findings:

1. Highly aspheric lenslets (HAL), MiSight contact lenses, low dose atropine 0.05 percent, Biofinity +2.50 D lenses, Defocus Incorporated Multiple Segments (DIMS) eye-glasses, and orthokeratology lenses were all effective in the control of myopia progression.
2. Low dose atropine 0.025 percent and extended depth of focus contact lenses have also been found to be effective, but with lower effect sizes.
3. Low-dose atropine 0.01 percent was not as effective in reducing axial length progression, according to some studies conducted in Asia.

The recent data on new eye-glasses, including DIMS and HAL, are cause for optimism given their considerable efficacy (5). However, these results need to be confirmed; current knowledge is limited in the length of study periods and number of populations studied. We also analyzed the efficacy and side effects of 0.01 and 0.5 percent atropine eye drops based on the studies conducted in non-Asian countries; we found that 0.01 percent atropine eye drops are effective in non-Asian children, achieving less side effects compared with 0.5 percent atropine eye drops.

Interestingly, the Cochrane systematic review and network meta-analysis was just published (5). The authors highlighted that the effects at one year provided evidence that interventions may slow refractive change and reduce axial elongation, although results were often heterogeneous. Moreover, they noted that much less is known about the effects at two or three years, and it is uncertain if effects are sustained.