Myopia progression and associated factors of refractive status in children and adolescents in Tibet and Chongqing during the COVID-19 pandemic

Abstract

ObjectivesTo investigate myopia progression and associated factors of refractive status among children and adolescents in Tibet and Chongqing in China during the COVID-19 pandemic.MethodsA population-based cross-sectional study was conducted to compare rates of myopia and high myopia, axial length (AL), spherical equivalent (SE), outdoor activity time, digital device use, and frequency of visual examinations for children and adolescents affected by myopia in Chongqing and Tibet in 2021.ResultsA total of 2,303 students from Chongqing and 1,687 students from Tibet were examined. The overall prevalence of myopia and high myopia in these two groups were 53.80 and 7.04% vs. 43.86 and 1.30%, respectively in each case. The Chongqing students had a longer AL than the group from Tibet (23.95 vs. 23.40 mm, respectively; p < 0.001). The mean SE of the students with myopic parents in Tibet was lower than that of the students in Chongqing with myopic parents (−2.57 ± 2.38 diopters (D) vs. −2.30 ± 2.34 D, respectively) (p < 0.001). Conversely, the mean SE of the students from urban areas in Chongqing was lower than that of the students in Tibet (−2.26 ± 2.25 D vs. −1.75 ± 1.96 D, respectively; p < 0.001). The Chongqing students exhibited lower SE (−2.44 ± 2.22 D) than their Tibetan counterparts (mean SE: −1.78 ± 1.65 D (p = 0.0001) when spending more than 2.5 h outdoors. For example, 61.35% of the students in Tibet spent more than 2.5 h outdoors daily, compared with 43.04% of the students in Chongqing. Correspondingly, the proportion of students using digital devices in Tibet (64.43%) was lower than that in Chongqing (100%). For the latter, 38.62% of the students in Chongqing spent more than 2.5 h online using digital devices compared to 10.49% of the students in Tibet. Greater monitoring of visual status was observed for the Chongqing students (mean SE: −1.90 ± 1.98 D) compared with students in Tibet (mean SE: −2.68 ± 1.85 D) (p = 0.0448), with the frequency of optimal examinations being every 6 months. Outdoor activity time was identified as a common risk factor for myopia in both of the populations examined, with odds ratios (ORs) of 1.84 (95% CI: 1.79–1.90) in Chongqing and 0.84 (95% CI: 0.73–0.96) in Tibet. Digital screen time was associated with myopia and high myopia in Chongqing, with ORs of 1.15 (95% CI: 1.08–1.22) and 1.06 (95% CI: 0.94–1.77), respectively. Digital screen time was also found to be a risk factor for high myopia in Tibet (OR: 1.21, 95% CI: 0.77–1.61). The type of digital devices used was also associated with myopia and high myopia in Tibet (OR: 1.33, 95% CI: 1.06–1.68 and OR: 1.49, 95% CI: 0.84–2.58, respectively). Finally, examination frequency was found to correlate with high myopia in the Tibet group (OR: 1.79, 95% CI: 0.66–2.71).ConclusionBased on our data, we observed that the prevalence of refractive errors in children and adolescents was significantly lower in Tibet than in Chongqing. These results are potentially due to prolonged outdoor activity time, and the type and time of use for digital devices that characterize the group of children and adolescents from Tibet. It is recommended that parents and children in Chongqing would benefit from increased awareness regarding myopia progression and its prevention.

Myopia prevalence and ocular biometry in children and adolescents at different altitudes: a cross-sectional study in Chongqing and Tibet, China

“…Epidemiological data show that the prevalence of keratoconus, pterygium, dry eye disease, cataract and strabismus is significantly higher in the highlands than in the lowlands2 6–9 and the cornea of the highlanders is thinner than that of the lowlanders 10 11. Our previous study also found that the prevalence of myopia among children and adolescents in Tibet was lower than that in the plains 12. However, it is unclear whether ocular biometry is associated with myopia prevalence between high and low altitude populations with different levels of UVR exposure.…”

“…Furthermore, our analysis of altitude subgroups revealed a decrease in the mean value of AL with increasing altitude. Although information regarding outdoor activities was not collected in this study for both groups, our previous research demonstrated that children and adolescents in Tibet spend more time outdoors than those in Chongqing,12 which may be synergistic with stronger UVR intensity and longer average daily sunshine in Tibet in slowing myopia progression.…”

“…And the increasing prevalence of myopia can be largely explained by increased educational pressures and reductions in the amount of time that children spend outdoors 16. Qian et al 17 and Wang et al 12 have reported that Tibetan children and adolescents at high altitudes had a lower prevalence of myopia than their counterparts at low altitudes. In line with their findings, our study also revealed that children and adolescents in Tibet presented a lower overall prevalence of myopia, shorter AL, higher SE and slower myopia progression in comparison to individuals in Chongqing.…”

Myopia Progression during COVID-19 Home Quarantine in Indonesia: A Retrospective Multicenter Cohort Study

“…Java-Bali is considered more urban than other areas in Indonesia archipelago. Living in urban area has been identi ed as an established environmental factor which promotes the progression of myopia through higher economic and civilization standards [18][19][20] . Studies comparing myopia prevalence pre and during pandemic also observed a signi cant increase in urban students [7,17,19] .…”

Comparative study of FLACS vs conventional phacoemulsification for cataract patients with high myopia

“…5,6 It has been shown that macular structure change negatively affected final surgical outcomes. 7 FLACS is an innovative technology which could decreased phacoemulsification time and energy by automating the formation of corneal incisions and flaps, continuous curvilinear capsulotomy, and lens fragmentation. It may offer benefit for cataract patients with other complicated ocular diseases such as vitreous abnormalities.…”