Caffeine Metabolite May Slow Progression of Myopia in Children: Study

Good vision makes life varied and colorful, but the popularity of modern electronic products has led to an increasing rate of myopia, with about 30 percent of the world’s population being nearsighted.

Now, a study has found that a caffeine metabolite may slow the progression of the common vision condition in which nearby objects are in focus, but faraway objects appear blurry.

A caffeine metabolite called 7-methylxanthine (7-MX) can slow the progression of myopia by inhibiting excessive lengthening of the eye (axial elongation), according to a study by Shenzhen Eye Center, School of Medicine at Jinan University and School of Optometry & Vision Sciences, Cardiff University.

The findings were published on Aug. 22 in the British Journal of Ophthalmology.

Nearsightedness usually develops during childhood and adolescence.

Using linear mixed models, the researchers analyzed longitudinal ciliary paralysis diopter and axial length data from 711 Danish myopic children treated with various doses of oral 7-MX (0-1200 mg/day). Among them, 624 children were taking 7-MX tablets daily at an average oral dose of 470 milligrams, while 87 were not taking them.

The children were followed for an average of 3.6 years, and myopia was determined by analyzing the error in longitudinal assessments of diopter, a measure used to assess the degree of eye function: -3.00D is considered as moderate myopia; -6D or more is considered as severe myopia.

Based on the data obtained, the researchers estimated that children who received 1000 mg of 7-MX daily would have a myopia progression rate of 1.43 days over the next six years, compared with 2.27 days if untreated.

When taking 1,000 mg of 7-MX per day, the child’s axial length would increase by 0.84 mm over the next 6 years, compared to 1.01 mm without treatment. It means that 7-MX treatment can inhibit axial elongation and reduced rate of myopia progression, and the higher the dose, the more effective it appears to be.

7-MX has been approved for the treatment of myopia in children in Denmark since 2009. However, it has not been fully validated in long-term studies so far. The study provides more conclusive evidences for the effectiveness of the caffeine metabolite. In addition, none of the children taking 7-MX reported any side effects during the monitoring period.

The findings echo results from experimental studies, said the researchers, who also acknowledged that the study was observational, and there were other potential factors such as genetics, time spent outdoors, ethnicity, and time spent working.

Existing myopia control interventions are not completely effective in preventing children from developing severe myopia, according to the research team. If causality and efficacy can be confirmed in future randomized controlled experiments, 7-MX could be a valuable myopia treatment.

A previous study of caffeine’s effects on dynamic vision (DVA) done in Canada found that caffeine can enhance recognition and detection accuracy of moving objects. The findings were published in the journal Psychopharmacology.

Half of the participants in the study were given caffeine capsules (4 milligrams per kilogram of body weight) and the other half were given placebo capsules. The researchers measured each subject’s visual acuity 60 minutes before and after consuming caffeine. The results revealed that DVA levels and accuracy of random movement paths were higher after caffeine intake (p < 0.001 and p = 0.002, respectively), and there was also a significant increase in reaction speed.

Caffeine had a positive effect on the subjects’ stimulant processing and decision-making time, the researchers said. Dynamic visual sensitivity involves eye movement speed and contrast sensitivity, the former being sensitive to caffeine intake as well.

According to the research team, caffeine consumption could indeed help people’s visual function by increasing alertness and wakefulness. This is especially true for everyday critical tasks like driving, cycling, or playing sports, which require people to pay attention to detailed information about moving objects when making decisions.

Myopia is a complex class of diseases caused by a combination of genes and the environment, Dr. Lei Shuhong, a medical doctor at the University of Tokyo, told The Epoch Times. For genetic inheritance factors, adolescents with myopic parents are at significantly increased risk of developing myopia, especially for pathological myopia, where genetic factors play a more pronounced role.

“There is no drug that can completely cure myopia, and laser surgery will bring more or less sequelae,” Lei said.

Lei believes that prevention is the key to protecting eyesight.

She suggested adjusting the brightness of electronic product displays in work to the appropriate value, such as 50 percent or 60 percent, as the brightness of the display being too high or too low can cause severe eye damage.

She also suggested setting electronic products’ home screen wallpaper to green to relieve eye fatigue.

“When working continuously, people can blink or close their eyes briefly to let eyes rest,” Lei said.

“Children, in particular, should try to stay away from electronic products. Ensure that you get enough sleep so that your eyes can rest adequately and eat more fresh fruits and vegetables in your regular diet.”