Highly aspherical lenslets reduce choroidal thinning in myopic kids: BMJ

A new study published in the British Journal of Ophthalmology suggests that, the choroidal thickness (ChT) of macula decreased after 2 years of single vision eyeglass lenses (SVL). When spectacles with slightly aspherical lenslets (SAL) and highly aspherical lenslets (HAL) were worn, ChT thinning was lessened or eliminated.

Between the retinal pigment epithelium and the sclera, the highly vascular choroid provides oxygen and nutrients to the outer retina and is crucial for vision-guided eye development. Two potential ways by which the choroid may affect optically directed eye development have been proposed. The retina is pushed toward the focus plane by a change in choroidal thickness. A typical technique for inducing experimental myopia or hyperopia in animal models is to implant positive or negative lenses in front of the eyes to cause myopic or hyperopic defocus. As a result, Yingying Huang and colleagues carried out this study to look at how they affected the retinal choroidal thickness of myopic children.

This double-masked, randomized trial recruited 170 kids aged 8 to 13 with myopia between 0.75 and 4.75 D, astigmatism less than 1.50 D, and anisometropia less than 1.00 D. The recipients of HAL, SAL, or SVL were distributed at random in a 1:1:1 ratio to the participants. Every six months, the perifoveal, parafoveal, and subfoveal ChT were assessed.

The key findings of this study were:

1. 154 individuals completed all the examinations. All 3 groups and areas of the ChT revealed significant changes over time (all p0.05).

2. After two years, the ChTs in the SVL group ranged from 20.75 (SD 22.34) m to 12.18 (22.57) μm depending on the area. ChT decreased slower in the SAL group compared to the SVL group.

3. ChT rose in the HAL group the first year before declining the next. The superior area saw the least reduction, and the perifoveal ChT declined more slowly than the parafoveal ChT.

After using spectacle lenses with aspheric lenslets for 2 years vs using SVL, the macular ChT in myopic children had a lesser degree of thinning, and the HAL had a greater impact. Instead of focusing just on the SF choroid in the clinic, more consideration to the superior choroid's characteristics should be mandated.

Reference: 

Huang, Y., Li, X., Wu, J., Huo, J., Zhou, F., Zhang, J., Yang, A., Spiegel, D. P., Chen, H., & Bao, J. (2022). Effect of spectacle lenses with aspherical lenslets on choroidal thickness in myopic children: a 2-year randomised clinical trial. In British Journal of Ophthalmology (p. bjophthalmol-2022-321815). BMJ. https://doi.org/10.1136/bjo-2022-321815