Researchers evaluating the effects of oral supplements of caffeine metabolite 7-methylxanthine (7-MX) have found it reduces the rate of axial length increase in myopic children.  

Although 7-MX has been used to treat Danish children’s myopia since 2009, researchers led by Dr Klaus Trier of Trier Research Laboratories, Denmark, said the supplement had not been fully evaluated in long-term studies. Having reviewed the records of 711 children treated for myopia at a Danish eye clinic between 2000 and 2021, on average, an 11-year-old taking 1,000mg 7-MX daily would experience a myopia increase of -1.43D over the next six years, compared with -2.27D without treatment; axial length would also increase by 0.84mm, compared with 1.01mm without treatment, they reported. “Existing myopia control intervention methods are not fully effective in preventing children from progressing to high myopia, and 7-MX may become a valuable supplement if causality and efficacy can be confirmed in future randomised controlled trials.”