14 DAY TRIAL // A new study published online in the British Journal of Ophthalmology, suggests that the eating disorder anorexia nervosa could cause serious eye damage, like anatomical and functional impairment of the optic nerve and the retina.
Anorexia nervosa is a condition that affects up to 3 percent of affluent women in developed countries, and even though it also affects men, the figures are ten times higher for women.
To see whether this illness affects the sight, researchers analyzed the thickness of the macula and its electrical activity in both eyes, in 13 women suffering from anorexia nervosa and also in 20 healthy women, of similar age.
The average age was 28 and the women suffering from the condition have had it for an average period of ten years.
The macula is very important as it lies near the center of the retina at the back of the eye and it handles the small details of the central vision ad it also processes light.
The several tests made by the scientists that assessed the way that the eye picked up fine details, central vision and color, concluded that there were no major differences in the visual performances in both groups, and that all women saw normally.
But a more thorough analysis revealed that the macula and nerve layers feeding the retinal nerve fiber layer, were much thinner in the eye of women with anorexia nervosa, that for the control group.
These women also had less firing of the neurotransmitter dopamine, or electrical activity, inside their eyes – the neurotransmission of dopamine is the motor of the brain's ability to process visual images.
Another strange thing observed by the team was that there were small differences between various patterns of anorexia too, for example the fovea (a small cavity in the macula, rich in light sensitive cone cells, or photoreceptors) was thinner in women who binged and purged than in those that simply eat very little.
At this stage, it seems uncertain if these differences in the eyes of anorexic women are a sign of progressive blindness or if they will come back to normal once the women start eating in a healthy way.
Anorexia nervosa is the third most common chronic disease among teenage women, and one in ten affected women will die from it.