Caffeine metabolites can slow the development of myopia in children

An observational study published online in the British Journal of Ophthalmology suggests that the metabolite 7-MX of caffeine may slow the development of myopia in

The researchers say that if proven safe and effective in large clinical trials, 7-MX could become a valuable treatment for situations where

Myopia occurs when the eye grows too long, stretching and thinning it, usually starting at the age of 6-7 and progressing to the age

It is associated with a high risk of various diseases that affect vision and eye health, including macular degeneration, cataracts, glaucoma, and retinal detachment

Preliminary studies have shown that the caffeine metabolite 7-methylxanthine, or 7-MX for short, inhibits excessive eye elongation (axial elongation

Since 2009, 7-MX has been used in Denmark to treat myopia

The researchers reviewed the medical records

The children underwent a comprehensive eye examination, including measuring the length of

Their average age at the time of initiation of treatment was 11 years (range 7-15 years), and their eye length and myopia were tracked for an average of 3 and a half years (range 11 months - 9 years).

Diopter (D) is the unit of measurement used to assess the degree of ocular function: the initial mean refractive error (myopia) was −2.

The average axial length was 24.

7-MX treatment is associated with slower myopia exacerbations and axial elongation, and high doses appear to be more effective

Based on these data, the researchers estimated that for a 7-year-old child with a typical refractive error of -2.

But if 1000 mg of 7-MX is taken daily, the child's degree of myopia will increase over the next 6 years - 2.

Similarly, if left untreated, the shaft length will increase by 1.

The researchers calculated that, on average, an 11-year-old who took 1,000 mg of 7-MX per day would increase his myopia by 1.

During the monitoring period, children who did not take 7-MX reported any side effects
.

The researchers say the findings echo the results of experimental studies
.
But they acknowledge that their study was observational and could not account for potential influencing factors such as genetic factors, outdoor time, race and time
spent working nearby.
Therefore, their findings cannot establish a causal relationship
.

"The question of causation and the magnitude of the possible therapeutic effect can only be determined by randomized
trials," they write.

But they concluded: "Existing myopia control interventions are not entirely effective in preventing children from developing into highly myopic, and if causation and efficacy can be confirmed in future randomized controlled trials, 7-MX may be a valuable addition
.
"