May home confinement during the COVID-19 outbreak worsen the global burden of myopia?

The novel coronavirus (2019-nCoV) that originated in Wuhan (China) has quickly spread all over the world. As of April 12, 2020, there have been with more than 1,600,000 confirmed cases and 100,000 deaths globally [1]. To restrict contact among individuals, governments have imposed unprecedented public health measures such as travel bans, workplace distancing, and schools closure. The aim of these measures is to reduce the size of the outbreak as well as its peak in order to decrease the amount of stress on healthcare systems.

In a recent correspondence on Lancet, Wang and colleagues pointed out that the measures ordered by the Chinese government to limit the spread of the novel coronavirus, and in particular schools closure, might have negative effects on children’s physical and mental health [2]. In fact, the authors stated that when children are out of school, they are physically less active and have longer screen time, irregular sleep pattern, and less favorable diets resulting in weight gain and loss of cardiorespiratory fitness. In addition, the psychological sphere can also be affected by this forced change of lifestyle.

We would like to add another piece to the puzzle of potential impacts of home confinement on children, which is the increased risk of myopia (namely, “quarantine myopia”). The prevalence of myopia has rapidly increased over the past few decades, particularly in countries from East and Southeast Asia. Insufficient time spent outdoors is recognized as an important risk factor for its development [3]. Furthermore, the duration and intensity of near work activities (e.g., reading and writing) are also associated with myopia [4]. The mechanisms of visual feedback regulating the eye growth are complex and not completely understood. Factors that may mediate the relationship between time spent outdoors and myopia include the brightness and chromatic spectrum of light, the energy at high spatial frequencies, the peripheral defocus, and the circadian rhythms [3].

According to UNESCO, more than 160 countries have closed schools in the attempt at containing the spread of COVID-19, and this measure involves over 87% of world’s student population [5]. An important consequence of home confinement on children’s health could be the development and/or the worsening of myopia. Since the exact duration of exposure is currently undetermined, it is difficult to estimate the effect from a refractive standpoint. A recent modeling study on influenza reported that in case of severe pandemics, the reduction of the cumulative disease incidence could be possible only with school dismissal lasting 16 weeks or longer [6]. A prolonged home confinement would very likely have a significant impact on the global incidence of myopia. This represents a serious public health concern for two main reasons. First, uncorrected myopia represents a major cause of visual disability in children, particularly in low- and middle-income countries. Second, high myopia in the current pediatric population is linked to a high risk of potentially sight-threatening complications in the next generations of elderly.

A range of new interventions for reducing the progression of myopia in children have now reached high level of evidence [7]. A recent network analysis indicated that the most effective options are muscarinic antagonists such as atropine and pirenzepine, whereas certain specially designed contact lenses including orthokeratology and peripheral defocus modifying contact lenses have moderate effects [7]. Therefore, a post-pandemic ophthalmological surveillance program for children with myopia involving decision-making based on demographical and clinical characteristics, risk factors, and individual preference should be considered in order to better control disease progression.