Adapting to astigmatism

A new study is blinkering theories that the growing eye may adapt to compensate for corneal astigmatism.

Researchers tracked 367 young patients with myopia over 14 years, measuring their eye structures as well as their refractive error, and compared these results to those of 204 people with no refractive error.

The aim of the study, published in the journal Optometry and Vision Science, was to see if the eye – and in particular, the lens – adapts as a young person ages to deliver correct focus.

If this theory is true, the researchers would have measured changes in patients’ internal astigmatism, the difference between the astigmatism of the cornea and the total astigmatism found across the whole eye.

The study did find that internal astigmatism was greater in patients without myopia, who appear to be better able to compensate for corneal astigmatism, Optometry and Vision Science editor, Dr Michael Twa, explained.

However, there was little change to internal astigmatism over time in these patients, Dr Twa highlighted, adding: “There was no evidence that the lens or other internal structural elements of the eye were actively compensating for corneal astigmatism.”

The research authors noted in the paper that new instruments that became available after the study began could provide new insights about the changes in the eye as a person grows.