Under-Correcting Myopia: A Short-Sighted Strategy for Progression?
Many believe that under-correction of myopia - prescribing lenses that are slightly less powerful than what is necessary for full correction - could be an effective strategy to slow the condition's progression. The logic behind this belief is that it might prevent or reduce the stimulus for myopia progression by reducing near work-induced accommodation (focusing) demand. However, is this approach beneficial in the long run, or could it further exacerbate the problem?
What does the research say?
Contrary to popular belief, multiple studies have concluded that under-correction of myopia may accelerate myopia progression rather than retard it. In a study by Chung, Mohidin, and O'Leary (2002), it was found that children aged 9-14 who had their myopia under-corrected experienced significantly faster myopia progression and axial elongation than those whose myopia was fully corrected. This indicates that under-correction might be a detrimental practice in managing myopia.
A follow-up study by Adler and Millodot (2006) confirmed these results. The study showed that under-correction of myopia caused more significant progression of the condition and axial length elongation over a period of two years than full correction.
What can be done to manage myopia progression?
Research suggests that approaches such as increased outdoor time, atropine eye drops, and orthokeratology could be effective in managing myopia progression (Xiong et al., 2017; Walline et al., 2020). These methods have been shown to slow down myopia progression to some extent.
Reference
Adler, D., & Millodot, M. (2006). The possible effect of undercorrection on myopic progression in children. Clinical & Experimental Optometry, 89(5), 315-321.
Chung, K., Mohidin, N., & O’Leary, D. J. (2002). Undercorrection of myopia enhances rather than inhibits myopia progression. Vision Research, 42(22), 2555-2559.
Walline, J. J., Lindsley, K. B., Vedula, S. S., Cotter, S. A., Mutti, D. O., & Ng, S. M. T. (2020). Interventions to slow progression of myopia in children. Cochrane Database of Systematic Reviews, (1).
Xiong, S., Sankaridurg, P., Naduvilath, T., Zang, J., Zou, H., Zhu, J., ... & Ho, A. (2017). Time spent in outdoor activities in relation to myopia prevention and control: a meta‐analysis and systematic review. Acta Ophthalmologica, 95(6), 551-566.
