Researchers at the Columbia University Medical Center uncovered a gene that leads to myopia, but only in those who spent a lot of time reading during childhood.
For a study published in the journal PLOS Genetics, the researchers used a database with information from about 14,000 people and found that those with a certain variant of the APLP2 gene were five times likelier to develop myopia by the time they reach their teenage years if they read for at least an hour every day when they were a child. Those who had the gene variant but didn't read as much carried no additional risk of getting myopia.
For decades, researchers have known that myopia is brought about by genetic and environmental factors but they didn't have hard proof to back it up. This study is the first solid evidence of the role interactions between genes and environment play in developing myopia.
However, Andrei Tkatchenko and colleagues are still unclear on how the APLP2 gene variant leads to myopia. They, however, think that the variant promotes myopia by elongating the eye. By cutting back on the amount of the gene variant then, it may be possible to lessen risks of environment-induced myopia.
The researchers are also still unsure of how levels of APLP2 could be reduced so coming up with a treatment could still take years. It is also likely that the treatment would be most effective when given to young children as that would make it possible to catch eye elongation before it begins and leads to myopia.
The researchers also suggest that children with the gene variant need to be identified before they start school, but this is still impossible at the moment because there are hundreds of genes that lead to myopia and so far only 25 have been identified. Even the APLP2 variant that is the focus of the study is relatively uncommon, found in just around 1 percent of the general public.
In the meantime, spending time outdoors may help in reducing the likelihood of myopia developing in children with the gene variant. The researchers recommend at least two ours of outdoor activity every day to counter the risks of developing myopia.
Keeping myopia from taking hold not only reduces the need to correct vision but can also help prevent eye conditions like glaucoma, retinal detachment and cataracts from developing later on in life and leading to blindness.
Photo: John Morgan | Flickr
