A natural breakdown product of caffeine can apparently slow down the progression of myopia in children. In a long-term study with a good 700 Danish children, the active substance 7-MX inhibited the excessive growth of the eyeball. As a result, the myopia of these children increased less than that of untreated children of the same age. This suggests that the active ingredient, which was approved by the Danish health authorities in 2009, can at least slow down myopia.
Almost 50 percent of people in Europe are short-sighted – and the number is growing. Ametropia occurs when children’s eyeballs grow too long, causing the image produced by the lens of the eye to form in front of the retina. In addition to a genetic predisposition, the main causes are frequent reading, sitting at the computer and others with one near focus linked activities. You can counteract this with as much as possible staying outdoorsbecause the UVB radiation the sun slows down eyeball growth.
As has now been shown, a natural breakdown product of caffeine could also slow down the progression of myopia in children. 7-Methylxanthine (7-MX) is formed when caffeine is metabolized in the human body. In contrast to caffeine, however, 7-MX can hardly penetrate the blood-brain barrier and therefore has no waking effect. Even in relatively high doses, it is considered harmless and tolerable.
Brake for the eyeball growth?
The interesting thing, however: In experiments with guinea pigs, rabbits and rhesus monkeys, 7-MX already showed a clear effect on the growth of the eyeball a few years ago. The caffeine breakdown product apparently promotes the stabilization of the dermis through collagen fibers and thus counteracts the expansion of the eyeball. In 2008, a one-year pilot study with 42 short-sighted children also showed the first promising results: when 400 milligrams of 7-MX were given daily, the short-sightedness worsened somewhat more slowly, and the children’s eyeballs also grew less.
An initial long-term study by Klaus Trier from the Trier Research Center in Hellerup, Denmark, and his colleagues shows what this means for the children in the long term. Between 2000 and 2021, they examined the eye development of 711 children between the ages of seven and 15. All children were short-sighted at the beginning of the study period, their diopter number was between -0.5 and -9. 624 of these children took between one and three tablets of 400 milligrams of 7-MX daily for several years.
Measurable dose-dependent effect
The result: Myopia progressed more slowly in the children who had taken 7-MX regularly. Her eyeball grew less and her diopter increased to a lesser extent. This braking effect was all the more evident the higher the daily dose of the active substance was and the earlier the treatment was started. At the same time, none of the children reported any side effects from taking the caffeine breakdown product, the team reports.
In concrete terms, the model-based evaluations revealed: “A child who is initially seven years old and has an initial myopia of -2.43 dioptres will gain around -3.49 dioptres over the next six years without treatment,” report Trier and his team. With a daily dose of 1,000 milligrams of 7-MX, on the other hand, it would only be -2.65 diopters more. The same applies to eyeball growth: Without treatment, the length of the child’s eye would increase by 1.80 millimeters in six years, with 7-MX it would be 1.63 millimeters.
“Could be clinically significant”
The results thus confirm the results of the pilot study and suggest that 7-MX can at least slow down the progression of myopia in children. According to the research team, the effect is even stronger than with previous approaches such as Atropine eye drops. “Effectiveness in this area could be clinically significant because it reduces the risk of myopia-related complications,” explain Trier and his colleagues. Severe myopia increases the risk of retinal tears, macular degeneration and glaucoma.
However, Trier and his team concede that their observational study is not yet conclusive evidence of causality. A clinical study with a placebo comparison would now have to be carried out for this. Possible influencing factors such as genes, time spent outdoors and lifestyle habits were also only partially recorded in the long-term study. Nevertheless, they see a promising approach against myopia in 7-MX.
“Previous interventions against myopia cannot prevent children from developing severe myopia,” says Trier. “Therefore, if the causal effect of 7-MX is confirmed, it could be a valuable adjunct therapy.” (British Journal of Ophthalmology, 2022; doi: 10.1136/bjo-2021-320920)
Source: BMJ