Variability of Accommodative Microfluctuations in Myopic and Emmetropic Juveniles during Sustained near Work.

Near work has been considered to be a potential risk factor for the onset of myopia, but with inadequate evidence. Chinese adolescents use digital devices for near work, such as study and entertainment purposes, especially during the COVID-19 pandemic. In this study, we investigated the influence of prolonged periods of near work on accommodative response, accommodative microfluctuations (AMFs), and pupil diameter between juvenile subjects of myopia and emmetropia. Sixty juveniles (30 myopes and 30 emmetropes) were recruited for the study. Participants were instructed to play a video game on a tablet PC at a distance of 33.3 cm for 40 min. Accommodative response and pupil diameter were measured with an open-field infrared refractometer in High-speed mode. Parameters of the subjects were measured once every 10 min, and analyzed by one-way repeated measure ANOVA for variation tendency. There were no significant differences between emmetropia and myopia groups with respect to age and sex (p > 0.05). The low-frequency component (LFC) of myopia gradually increased with time, reached a peak at 30 min, and then declined (p = 0.043). The high-frequency component (HFC) of myopia also reached a peak at 30 min (p = 0.036). Nevertheless, there was no significant difference in the LFC (p = 0.171) or HFC (p = 0.278) of the emmetropia group at each time point. There was no significant difference in the mean and standard deviation of the accommodative response and pupil diameter both in emmetropic and myopic juveniles. Compared with juvenile emmetropes, myopes exhibit an unstable tendency in their accommodation system for prolonged near work at a certain time point. Accommodative microfluctuations may be a sensitive, objective indicator of fatigue under sustained near work in juvenile myopes.

Online Learning-Related Visual Function Impairment During and After the COVID-19 Pandemic.

This study aimed to review the consequences of increased online learning, which was precipitated by the coronavirus disease 2019 (COVID-19), on visual function, as well as the methods for preventing the associated visual impairment. The recent finding implies that a higher incidence of myopia may be observed during the pandemic than that before. The myopia prevalence was 59.35% in COVID-19, which was higher than that in the normal period. COVID-19-related influence of developing myopia among students should be addressed and under control. Online learning precipitated by COVID-19 is likely to increase the global burden of visual function impairment. This review highlighted useful measures to prevent online learning-related visual function impairments, including the following: (1) desktop illumination of no >300 lx, online learning time for primary, and middle-school students of no more than 20-30 min per session; (2) daily video time for preschool children not exceeding 1 h, and for school-age children and adolescents not exceeding 2 h; (3) after every 30-40 min of online learning, moving eyes away from the screen or closed for 10 min; (4) engaging in outdoor activities for ≥ 2 h a day; (5) suitable screen and learning environment settings and correct postures for reading and writing; (6) sufficient sleep and proper nutrition. Preventing online learning-related visual impairment during and after this unprecedented pandemic will facilitate future ophthalmic practice.

Rates of Myopia Development in Young Chinese Schoolchildren During the Outbreak of COVID-19.

Importance: During the outbreak of COVID-19, outdoor activities were limited and digital learning increased. Concerns have arisen regarding the impact of these environmental changes on the development of myopia. Objective: To investigate changes in the development of myopia in young Chinese schoolchildren during the outbreak of COVID-19. Design, Setting, and Participants: In this observational study, 2 groups of students from 12 primary schools in Guangzhou, China, were prospectively enrolled and monitored from grade 2 to grade 3. Comparisons between the exposure and nonexposure groups were made to evaluate any association between environmental changes during the COVID-19 outbreak period and development of myopia. The exposure group received complete eye examinations in November and December 2019 and November and December 2020. The nonexposure group received examinations in November and December 2018 and November and December 2019. Main Outcomes and Measures: Changes in cycloplegic spherical equivalent refraction (SER), axial length (AL) elongation, and myopia incidence from grade 2 to grade 3. Results: Among the 2679 eligible students in grade 2 (mean [SD] age, 7.76 [0.32] years; 1422 [53.1%] male), 2114 (1060 in the nonexposure group and 1054 in the exposure group) were reexamined in grade 3. Compared with the period from November and December 2018 to November and December 2019, the shift of SER, AL elongation, and myopia incidence from grade 2 to grade 3 from November and December 2019 to November and December 2020 was 0.36 D greater (95% CI, 0.32-0.41; P < .001), 0.08 mm faster (95% CI, 0.06-0.10; P < .001), and 7.9% higher (95% CI, 5.1%-10.6%; P < .001), respectively. In grade 3 students, the prevalence of myopia increased from 13.3% (141 of 1060 students) in November and December 2019 to 20.8% (219 of 1054 students) in November and December 2020 (difference [95% CI], 7.5% [4.3-10.7]; P < .001); the proportion of children without myopia and with SER greater than -0.50 D and less than or equal to +0.50 D increased from 31.1% (286 of 919 students) to 49.0% (409 of 835 students) (difference [95% CI], 17.9% [13.3-22.4]; P < .001). Conclusions and Relevance: In this study, development of myopia increased during the COVID-19 outbreak period in young schoolchildren in China. Consequently, myopia prevalence and the proportion of children without myopia who were at risk of developing myopia increased. Future studies are needed to investigate long-term changes in myopia development after the COVID-19 pandemic.