Interventional options for myopia are gaining favor as clinicians and researchers continue to build up a body of knowledge about their uses and outcomes. Previous studies have looked at defocus incorporated multiple segment (DIMS) lenses, orthokeratology (ortho-K) and atropine as methods to reduce myopia progression, but how do these treatments compare to each other?

The researchers advise beginning with orthokeratology and then considering adding atropine in fast progressors. For those with financial or clinical contraindications to ortho-K, DIMS plus atropine may be a good alternative. Click image to enlarge.

That was the aim of a new study conducted in Beijing, which compared DIMS lenses, ortho-K, DIMS lenses plus atropine and ortho-K plus atropine in children ages six to 14 years old. Out of a total of 292 participants, 167 were selected to undergo one of the aforementioned treatment options. The groups were divided somewhat evenly, with 41 subjects in the DIMS group, 41 subjects in the ortho-K group, 42 subjects in the DIMS plus atropine group and 43 subjects in the ortho-K plus atropine group. Overall, the subjects’ mean spherical equivalent refraction was -2.08D ± 1.05D and their mean axial length was 24.39mm ± 0.72mm.

After a period of 12 months, there was no significant difference in axial length change between the DIMS (0.22mm) and ortho-K (0.20mm) groups. However, both the DIMS plus atropine (0.15mm) and ortho-K plus atropine (0.12mm) groups showed improved reduction of axial elongation.

Then, the researchers took their findings even further and created subgroups based on age. They noted that in the six- to 10-year-old subgroup, there was a significant difference in axial length change between ortho-K plus atropine (0.14mm) and DIMS (0.27mm), but no other significant difference was reported between the other treatments. In the 10- to 14-year-old subgroup, the difference in axial length change between ortho-K plus atropine (0.11mm) and DIMS (0.16mm) was insignificant, while the differences between ortho-K (0.20mm) and ortho-K plus atropine, ortho-K and DIMS plus atropine (0.07mm), and DIMS monotherapy and DIMS plus atropine were significant.

Since the researchers followed their subjects over a one-year period, they could not report any longer-term effects of DIMS and ortho-K along with atropine. Furthermore, they failed to measure parameters such as pupil size, accommodation and peripheral refractive status. Due to these limitations, they believe their research needs further investigation in order to better understand the impact and differences between ortho-K and DIMS. 

“Our results provide clues for clinicians in guiding myopia control in children,” reported the researchers in their study for the British journal Eye. “Younger children might be treated with ortho-K lenses, and if myopia is growing quickly, a combination of 0.01% atropine can be administered. However, if patients consider the adverse effects of ortho-K lenses or economic reasons, younger children can receive DIMS lenses combined with 0.01% atropine. For older children, DIMS monotherapy might tend to be used first for myopia control. To develop a more precise myopia control strategy, a randomized clinical trial is warranted.”