New insights gained by researchers into the eye of the zebrafish could lead to a better understanding of human eye problems and improve treatments for them.
A research team from Purdue University uncovered the role of an enzyme in regulation of eye size in the fish.
If the enzyme holds a similar role with regard to human eyes, treatment for conditions like nearsightedness and farsightedness could be vastly improved, according to the research which was published in the journal PLoS ONE.
Lead researcher Zeran Li explained: "New insights into the process of eye-size control in zebrafish may help our understanding of the regulation of eye size in humans.
"Vision problems occur when the size or shape of the eye changes, and what causes this is unclear. Perhaps this research will lead to a better understanding of this mechanism and the discovery of a new treatment for these problems."
Li had previously seen that zebrafish embryos that were treated with a chemical called phenylthiourea, which blocks the formation of black pigment, had smaller eyes than untreated fish.
It was found that in addition to blocking the form of black pigmentation, the chemical inhibits thyroid activity.
The thyroid regulates metabolism and influences growth, and it was therefore believed that a suppression of the thyroid hormone could cause the reduction in eye size.
However, Li predicted that phenylthiourea could suppress thyroid hormone production because it has the same structure as a well-known thyroid inhibitor.
After testing the effects of several different inhibitors, she discovered that only those that stopped production of the enzyme thyroid peroxidase caused smaller eye size.
"If thyroid peroxidase has a specific role in the regulation of eye growth, it would be logical for it to express in the eye," Leung said.
"Perhaps a localised manipulation of its activity in the eye could be used as a strategy to correct some vision problems. Of course, first we must learn much more about how it regulates eye size."