Children with Pseudomyopia More Likely to Develop Myopia, Study Finds

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Results from a large, prospective population-based cohort study provide evidence that pseudomyopia is an independent risk factor for myopia development among school-aged children.¹

The research shows pseudomyopia was common (37.19%) among nearly 3000 children included in the study from 9 schools in China, suggesting the importance of identifying new cases and uncovering the underlying cause.

“Our research provides new considerations for myopia prevention and control in children and opens up a new window for future research to investigate the mechanisms underlying the transition from pseudomyopia to myopia,” wrote the investigative team, led by Hongsheng Bi and Yuanuuan Hu, Affiliated Eye Hospital, Shandong University of Traditional Chinese Medicine.

Myopia is a major global health problem and remains a significant public health and economic concern in China. Home quarantine due to the COVID-19 pandemic has accelerated myopia progression in children in China, secondary to reduced time outdoors and excessive near work from online learning.²

Pseudomyopia, a subtype of excessive accommodation, has been defined in literature as a spherical equivalent of ≤-0.50 diopters (D) before cycloplegia and >-0.50D after cycloplegia. Nearly 24.1% of Chinese children were found to have pseudomyopia, but it remains unknown whether its presence is associated with a higher risk of myopia development. The current analysis investigated whether pseudomyopia is an independent risk factor for myopia onset based on a population-based cohort study.

The study used multistage stratified cluster sampling to recruit children from 9 schools in rural and urban settings in China. Stratification of clusters confirmed that a representative sample of non-myopic children from 4 years to 17 years was included in the study. Baseline examinations were performed in September 2020, while the 6-month follow-up examinations were conducted from March to April 2021.

Two ophthalmologists performed slit-lamp ocular examinations for all children at each study visit. All other examinations were performed by trained optometrists, including uncorrected distance visual acuity, intraocular pressure management, laser interferometry-based ocular biometry, non-cycloplegic and cycloplegic autorefraction, as well as binocular accommodative facility and amplitude of accommodation. Myopia was defined as SE ≤−0.50 D after cycloplegia, while pseudomyopia definition was based on prior literature (SE ≤−0.50 D before cycloplegia and >−0.50 D after cycloplegia).

A total of 2790 non-myopia children completed the baseline examinations and 2328 children (83.44%) completed the follow-up visit in March 2021. Parental concerns around performing cycloplegia again were the primary reason for the loss of follow-up. Investigators identified no significant difference in demographics between those who completed follow-up and those who were lost to follow-up.

Within 6 months, the analysis revealed 21.1% (n = 355 of 1680) pseudomyopic eyes progressed to myopia, with a corresponding proportion of 3.8% (n = 110 of 2879) in non-myopic and non-pseudomyopic eyes.

After adjusting for multiple myopia risk factors, such as baseline cycloplegic SE, near work, and outdoor time, investigators found pseudomyopia was an independent risk factor for myopia onset (relative risk, 2.52; 95% CI, 1.86 - 3.42).

Using multiple regression analysis, investigators found pseudomyopic children with more myopic cycloplegic SE (P <.001), a smaller difference between cycloplegic and non-cycloplegic SE (P <.001), poorer distance uncorrected visual acuity (P <.001), and higher binocular amplitude of accommodation (P <.001) had a higher risk of myopia development.

“Despite the fact that we identify pseudomyopia as an independent risk factor for myopia onset, clinicians should envisage that the children, once they are in premyopia status, are at significantly increased risk of developing myopia, and thus all prophylactic measures should be adopted, for example, outdoor time intervention,” investigators wrote.

References

1. Sun W, Yu M, Wu J, et al. Pseudomyopia as an independent risk factor for myopia onset: a prospective cohort study among school-aged children. British Journal of Ophthalmology Published Online First: 04 August 2023. doi: 10.1136/bjo-2022-322330
2. Chang P, Zhang B, Lin L, et al. Comparison of myopic progression before, during, and after COVID-19 lockdown. Ophthalmology 2021;128:1655–7. doi:10.1016/j.ophtha.2021.03.029