Orthokeratology better controls axial length (AL) elongation in children with myopia than 0.02% atropine, according to research out of China published in the journal Eye & Contact Lens.
According to investigators, orthokeratology is currently the most common treatment method clinicians use to slow down the progression of pediatric myopia in Mainland China. Myopia is also commonly controlled with orthokeratology, low-dose atropine eye drops, contact lenses with peripheral defocus, increased outdoor activity, and sunlight exposure. However, researchers have found that some children with myopia do not benefit from orthokeratology for various reasons ranging from the treatment’s strict clinical indications and compliance requirements to discomfort during nighttime wear and the risk of the patient developing infective keratitis.
On the other hand, low-dose atropine is effective and convenient, but rebound effects can occur after discontinuing use. Atropine also can cause side effects such as photophobia, blurry vision, allergic conjunctivitis, and eyelid dermatitis, according to researchers.
This study sought to determine which treatment was most effective at controlling AL elongation in pediatric patients with myopia. Investigators enrolled 247 children with myopia who received either 0.02% atropine (n=142) or underwent orthokeratology (n=105) in the study. They recorded data on AL and other baseline parameters at baseline and after 1 year and 2 years of treatment.
According to the team’s findings, the mean changes in AL in the atropine group in the first and second years of treatment were 0.30 mm ± 0. 21 and 0.28 ± 0.20 mm, respectively. For the orthokeratology group, the mean changes for the same periods were 0.16 mm ± 0.20 mm and 0.20 mm ± 0.16 mm, respectively. The researchers also found that after 2 years of treatment, differences in AL elongations between the 0.02% atropine and orthokeratology groups were even greater (0.58 mm ±0.35 mm and 0.36 mm ± 0.30 mm, respectively, P =.007).
Multivariate regression analyses showed that AL elongation occurred significantly faster in the atropine group than in the orthokeratology group (ß=0.18, P =.009).
In multivariate regression analyses, younger age and shorter baseline ALs were associated with a rapid AL elongation in the atropine group (ßage=20.04, P =.01; ßA=20.17, P =.03). The research also shows younger age, lower baseline spherical equivalent refractive error, and shorter baseline AL were associated with a more significant increase in AL in the orthokeratology group (ßage=20.03, P =.04; ßSER=0.06, P =.03; ßAL=20.11, P =.009). Faster AL elongation was found in the atropine group compared with the orthokeratology group at higher baseline spherical equivalent refractive error (P =.04, interaction test).
Limitations of this study include its historical control design. Second, there was a selection bias for the patients whose basic parameters matched incompletely, but the potential confounders were adjusted. Another limitation of the study was that the rebound effect on AL elongation wasn’t considered. Also, the team did not measure the shelf life of 0.02% atropine.
Future studies should investigate the elution period design to confirm the researchers’ findings. Moreover, while the properties of the 0.02% atropine used in this study were relatively stable, the shelf life of different low-dose atropine will also need to be measured.
Lyu Y, Ji N, Fu AC, et al. Comparison of administration of 0.02% atropine and orthokeratology for myopia control. Eye Contact Lens. 2021;47(2):81-85. doi:10.1097/ICL.0000000000000699.