Votre travail commun :
Pain can be seen in the eyes
Pupil size and contraction when stimulated by light could be good indicators of the intensity of pain a patient feels.
Since eyes are the mirror of the soul, there is nothing surprising after all in being able to perceive pain in them. Reducing the subtlety of a gaze/look to a few easily measured parameters wasn’t (that) simple however. Researchers from Diderot University in Paris in association with the French national institute for medical research set themselves this task.
Jean Guglielminotti, an anesthetist, chose to study pupil diameter and contraction intensity after luminous stimulation in an extreme case: childbirth. “We wanted to establish the connection between two parameters, pain of (uterine) contractions during delivery and relief via/by/thanks to epidural analgesia,” he explains. With his team he used cameras to film the pupils of twenty-four women in four distinct situations: before and after epidural, with and without contractions.
Quantifying the effectiveness of painkillers
The results confirm preliminary studies carried out in the nineties according to which the pupil diameter increases with pain. They also established that contraction is more noticeable after luminous stimulation when the pain is strong. On the other hand these minor variations are very hard to detect with/barely visible to the naked eye. Precise and extremely fast cameras are indispensable.
Another difficulty was that the researchers did not manage to determine a generic threshold allowing them to confirm/check whether a person is suffering or not. “Nevertheless, each person could be his/her own witness. That/this means that by measuring the evolution of these parameters over time, before and after analgesic treatment for example, it would be possible to establish the variation in pain and thereby know if the treatment has been effective or not,” explains Jean Guglielminotti.
This study, recently published in Anesthesia and Analgesia, could/might therefore enable doctors to judge how effective an analgesic is in a more objective manner. At this time, the only way to gauge a patient’s pain is to ask him to rank it on a scale from one to ten. The scientists also hope to develop a method allowing them to detect pain in people who cannot communicate: young children, comatose patients or those suffering from locked-in syndrome.