Medical Bulletin 24/ July/ 2024

A recent study has revealed a concerning link between excessive screen time and the rising incidence of dry eye disease (DED) among school children. Conducted by researchers from BJ Medical College in Ahmedabad, PDU Government Medical College in Rajkot, and Government Medical College in Satna, the study highlighted that children who use digital devices for more than 3 to 3.5 hours a day are at a significantly higher risk of developing DED.

The study was published in the Indian Journal of Ophthalmology.

Dry eye disease is characterized by insufficient tear production or rapid tear evaporation, leading to symptoms such as discomfort, redness, and blurry vision. The study, which examined 462 school children with an average age of 11 at government hospitals, found that 90% of the participants had mild to severe DED. Symptoms included blurry vision, redness, and itchy or watery eyes.

The research identified that 8 to 10 hours of daily screen use—encompassing recreational, co-curricular, and educational activities—contributed to this condition. Children diagnosed with moderate to severe DED were found to spend 60 to 70% more time on screens compared to their peers with normal eye health. The increased screen time, coupled with a decreased blinking rate, has created a significant burden, affecting 20% of the children studied.

Over a four-day period, the participants reported using computers for 30 minutes to 2 hours for academic purposes and 45 minutes to 2 hours for extracurricular activities. Mobile device usage ranged from 45 minutes to 2 hours for educational purposes and 2 to 3.5 hours for entertainment.

The study reflected broader trends highlighted by a nationwide survey, which found that 95% of children aged 0–8 years used mobile devices in 2017, with 42% having their own tablets. On average, children under 8 spent 2 hours and 19 minutes daily on-screen media. The increase in digital media consumption among youth poses a new challenge of ocular problems and digital eyestrain at an early age, according to the researchers.

To mitigate these issues, the study recommended limiting daily screen time to below 3 hours. It also advocates for the 20/20/20 rule: every 20 minutes, children should look away from the screen, focus on an object at least 20 feet away, for at least 20 seconds. Additionally, parents and teachers are encouraged to implement frequent breaks, suggesting that children take a 10-minute walk away from screens every hour. Utilizing timers or software to remind children to take breaks could further help manage screen time effectively.

"Even an extra half hour of computer use per day can increase the likelihood of moderate to severe dry eye. Policymakers should aim to limit children's screen time to less than 3 hours a day," said the authors.

Reference: Jadeja, Jagruti N; Shroff, Kruti V; Shah, Ashka; Pandey, Ashish1; Dubey, Shubhra2. Association of digital device usage and dry eye disease in school children. Indian Journal of Ophthalmology 72(7):p 1031-1036, July 2024. | DOI: 10.4103/IJO.IJO_703_23

Many people take daily multivitamins with the hope of extending their lifespan, but recent research indicated these supplements might not deliver on that promise.

The study published in JAMA Network Open analysed data from nearly 400,000 adults over a 20-year period. The median age of participants was 61.5 years, and they were generally healthy with no chronic disease history.

The study found no significant evidence that daily multivitamin use reduced the risk of death from major conditions like heart disease or cancer. In fact, participants who took multivitamins were slightly more likely (4%) to die over the study period compared to those who did not take the supplements. However, it’s important to note that the research did not include individuals with pre-existing vitamin deficiencies, which means the results may not apply to those who require specific vitamins for health reasons.

Multivitamins may not significantly impact longevity for healthy individuals. However, multivitamins can still be beneficial for those with active deficiencies or risk factors, such as poor diet, vegan diets, or a history of bariatric surgery,” said Stephen Vogel, a family medicine physician.

The study highlighted that food and diet are most important for health and longevity and that not everyone needs to take a multivitamin, says Prest. Aside from multivitamins, focus on healthy lifestyle habits like getting enough sleep, eating plenty of fruits and vegetables, and moving your body daily to help you live a longer, healthier life.

“We recommend discussing vitamin supplements with your healthcare provider. Meeting with a registered dietitian can also provide personalized guidance based on your diet and health history. Supplementation may benefit those with alcohol addiction, poor diets, vegan diets, or a history of bariatric surgery. However, for those with a healthy lifestyle or concerns about the cost of daily multivitamins, supplementation is optional. There's minimal risk in taking multivitamins, so use this information to make informed decisions,” said the authors.

Reference: Barnard ND, Kahleova H, Becker R. The Limited Value of Multivitamin Supplements. JAMA Netw Open. 2024;7(6):e2418965. doi:10.1001/jamanetworkopen.2024.18965

A recent study published in Psychophysiology highlighted the relationship between anxiety and brain function, particularly how anxiety impacts the cognitive control network. This research revealed that major anxiety disorders are linked to decreased activity in specific brain regions, which could serve as neural markers for anxiety symptoms.

Anxiety affects millions globally, ranging from mild to severe forms. While mild anxiety can heighten awareness, severe anxiety leads to debilitating disorders that impair daily functioning and often coexist with other mental health issues, like depression. Understanding the neural mechanisms behind anxiety is essential for developing effective treatments.

Previous research has shown inconsistent findings regarding anxiety’s impact on brain activity, especially in the frontal cortex.

In the study, researchers recruited 366 participants from Huazhong University of Science and Technology in Wuhan, China. Using the Hospital Anxiety and Depression Scale (HADS), participants were categorized into three groups based on anxiety levels: healthy controls, mild anxiety, and major anxiety.

To measure brain activity, the study utilized functional near-infrared spectroscopy (fNIRS), a non-invasive method that monitors blood oxygen levels in the brain. Participants performed a verbal fluency task (VFT), which activates brain regions involved in cognitive control.

The study found significant differences in brain activity among the groups. Specifically, there was a negative correlation between anxiety severity and activation in the right dorsolateral prefrontal cortex and the left frontal eye fields. Higher anxiety levels corresponded to lower activity in these regions during the VFT. Participants with major anxiety showed significantly lower activation in the right dorsolateral prefrontal cortex and the left frontal eye fields compared to healthy controls.

These findings suggested that decreased activity in these brain regions could be a neural marker for major anxiety disorders. The cognitive control network, crucial for regulating thoughts and emotions, appears impaired in individuals with major anxiety.

The study underscored the importance of targeting specific brain regions in treatments for anxiety disorders. Future research would incorporate comprehensive measures of anxiety and depression and include deeper brain regions like the amygdala to provide a more complete understanding of the neural mechanisms underlying anxiety.

Reference: Qinqin Zhao, Zheng Wang, Caihong Yang, Han Chen, Yan Zhang, Irum Zeb, Pu Wang, Huifen Wu, Qiang Xiao, Fang Xu, Yueran Bian, Nian Xiang, Min Qiu; Anxiety symptoms without depression are associated with cognitive control network (CNN) dysfunction: An fNIRS study; Psychophysiology; https://doi.org/10.1111/psyp.14564