Myopia: Mechanisms and Strategies to Slow Down Its Progression

Abstract

This topical review aimed to update and clarify the behavioral, pharmacological, surgical, and optical strategies that are currently available to prevent and reduce myopia progression. Myopia is the commonest ocular abnormality; reinstated interest is associated with high and increasing prevalence, especially but not, in the Asian population and progressive nature in children. The growing global prevalence seems to be associated with both genetic and environmental factors such as spending more time indoor and using digital devices, particularly during the coronavirus disease 2019 pandemic. Various options have been assessed to prevent or reduce myopia progression in children. In this review, we assess the effects of several types of measures, including spending more time outdoor, optical interventions such as the bifocal/progressive spectacle lenses, soft bifocal/multifocal/extended depth of focus/orthokeratology contact lenses, refractive surgery, and pharmacological treatments. All these options for controlling myopia progression in children have various degrees of efficacy. Atropine, orthokeratology/peripheral defocus contact and spectacle lenses, bifocal or progressive addition spectacles, and increased outdoor activities have been associated with the highest, moderate, and lower efficacies, respectively.

Figure 1

Odds ratios for near activity risk and the mean outdoor time on myopia at the age of 9 years. Near activities risk tertiles represent the combined risk of the computer use, reading, and reading distance. The outdoor time was classified into <7, 7–14, and >14 hours per week. The subset with low near risk and >14 hours per week of outdoor exposure was the reference subset (adapted from the study by Enthoven et al.).

Figure 2

Peripheral hyperopic defocus (red arrow) might lead to axial elongation. A myopic defocus (green arrow) can be achieved with orthokeratology, contact lenses, laser refractive surgery, and spectacle lenses (defocus incorporated multiple segment lenses and Apollo progressive addition lenses).

Figure 3

Single-vision contact lenses (CLs) provide a peripheral hyperopic defocus. A peripheral myopic defocus can be achieved with peripheral gradient CL, bifocal CL, and EDOF CL.

Figure 4

Epithelium remodeling is achieved with orthokeratology. Central corneal flattening is accompanied by a midperipheral steepening (tangential map, (a)), due to accumulation of the epithelium (epithelial thickness map, (b)).