Evaluating the impact of pandemic lifestyle changes for Dutch teens

Paper title:  The effect of home confinements on myopic risk profile in European adolescents: The Generation R Study.

Authors:  Sander Kneepkens (1)(2), Clair Enthoven (3), Willem Tideman (1)(4), Jan Roelof Polling (1)(5), Caroline C W Klaver (1)(6)

1. Ophthalmology & Epidemiology, Erasmus MC, Rotterdam, Zuid-Holland, Netherlands
2. Generation R, Erasmus MC, Rotterdam, Zuid-Holland, Netherlands
3. Child and Adolescent Psychiatry, Erasmus MC, Rotterdam, Zuid-Holland, Netherlands
4. Ophthalmology, Martini Ziekenhuis, Groningen, Groningen, Netherlands
5. Optometry/Orthoptics, Hoge school Utrecht, Utrecht, Zuid-Holland, Netherlands
6. Ophthalmology, Institute of Molecular and Clinical Ophthalmology Basel, Basel, Basel-Stadt, Switzerland

Date:  June 2022

Reference:  Kneepkens S, Enthoven E, Tideman W, Polling JR, Klaver CWC.  The effect of home confinements on myopic risk profile in European adolescents: The Generation R Study. Invest. Ophthalmol. Vis. Sci. 2022;63(7):258 - A0112. [Link to abstract]

During the COVID-19 outbreak, the Netherlands introduced an 'intelligent lockdown' which allowed children to spend time outdoors during the pandemic.  Where home confinement was stricter (China, for example), a measurable increase in myopia incidence has been seen.^1,2

This study explored the association between COVID lockdown restrictions and rick factors for myopia for 1101 European teenagers.

The teens who participated had a mean age of 16.3 ± 3.7yrs and featured in the population-based prospective birth-cohort Generation R study in the Netherlands.  They had previous cycloplegic refraction at age 13 and were myopic (-0.50D or over) and non-myopic.

They completed a questionnaire on their lifestyle between March and October 2020 to encompass the period before, during and after the lockdown.

The questions assessed:

• Time spent outdoors
• Time spent online (regardless of device used)
• Time spent on near work (schoolwork and otherwise)

Per day, the children spent more time online and on near school-work during and after lockdown (+113 and +73 minutes, respectively). They used hand-held devices and other devices more for +49 and +7 minutes, respectively.

Children of non-European descent spent longer online per day (235 mins per day v 260 mins per day) and on non-school near-work (452 mins per day v 559 mins per day).

The time spent outside did not increase greatly and was within a range of ± 2hrs per day.  Non-educational near-work was only increased during the lockdown period with an extra +176 minutes per day and no significant behavioural differences were found between myopic and non-myopic children.

Due to the type of home confinement imposed in the Netherlands, Dutch teenagers were still able to spend time outdoors during lockdown, despite spending more time using digital devices for near-work.

Where lockdown rules have differed by country, so has the amount of time children have spent outside in that period. Although children have now resumed normal schooling, some children may still be spending more time indoors and less time outside. This means that eye care practitioners should still encourage a balanced lifestyle and provice advice on avoiding excessive near work.

Previous studies using data from China by Wang et al¹ and Xu et al² looked at the impact of lockdown on myopia prevalence and progression.  Wang et al found younger children may be more susceptible to changes in their environment than older children.  Xu et al showed that there was a risk of further progression in older children who were already myopic.

This study shows that teenagers have still been impacted by the increased home learning, even if they were still able to spend time outdoors. Practitioners can be watchful of myopia progression in teens as well as in younger children.

The abstract is focusing on behavioural changes due to the pandemic lockdown. The children from the Generation R study had cycloplegic auto-refraction performed at age 13yrs. The full article may contain detail on refractive changes after the lockdown period and if they are attributable to the increased near work.

Title:  The effect of home confinements on myopic risk profile in European adolescents: The Generation R Study.

Authors:  Sander Kneepkens, Clair Enthoven, Willem Tideman, Jan Roelof Polling, Caroline C W Klaver

Purpose:  To battle the spreading of the COVID-19 virus, all over the world measures like home confinement and nation-wide lockdowns have been implemented at regular intervals. These measures have shown an increase in myopic incidence particularly in China, which applied a very strict lockdown and home confinement. The Netherlands used a so called "intelligent lockdown" which allowed children to go outside. We evaluated the association between COVID restrictions and myopia risk factors in a European cohort of adolescents.

Methods:  A total of 1101 participants (mean age 16.3 ± 3.65yrs) of the population-based prospective birth-cohort study Generation R filled in a questionnaire about their behaviour before, during, and after lockdown in the Netherlands. These participants had undergone cycloplegic refractive error measurement at 13 years of age. We evaluated time spent outdoors, time spent online (handheld or other devices), time spent on near work (education and non-educational) from March-October 2020 in myopic (spherical equivalent <-0.5D) and non-myopic children. We used a repeated measures ANOVA to compare differences between these time periods, and logistic regression corrected for age, gender, and ethnicity to evaluate differences between myopic and non-myopic children.

Results:  During and after lockdown the children spent significantly more time online (+113 and +59min/day) on both hand-held (+64 and +10 min/day) and other devices (+49 and +7 min/day), and on educational near-work (+73 and +63min/day). Non-educational near work increased only significantly during lockdown (+176 min/day). Time spent outside did not change significantly and was ±2 hours/day. Children of non-European descent spent more time online (235min/day vs 260 min/day, P= 0.004) and on non-educational near work (452 min/day vs 559 min/day, p=0.0002). We found no significant difference in behaviour between myopic and non-myopic children.

Conclusions:  The Dutch lockdown for COVID increased digitized near work in adolescents, but did not affect outdoor exposure. Children without myopia did not do better than those already myopic. Based on these results, we expect that the COVID pandemic will also lead to an increase in myopia prevalence and progression in European children, but to a lesser extent than in Asia.

[Link to abstract]