Chiropractic techniques can harm vision, a new case study illustrates.
A case report — now featuring in the American Journal of Ophthalmology Case Reports — has analyzed the situation of a 59-year-old woman who experienced patchy vision after receiving chiropractic intervention.
She noted that she had a "tadpole-shaped" spot in her vision soon after having undergone high-velocity cervical spine manipulation, which she sought in order to relieve a problem with headaches.
The following day, the woman's eyesight got even worse.
Dr. Yannis Paulus, a retina specialist at the University of Michigan Kellogg Eye Center in Ann Arbor, analyzed the woman's case with Dr. Nicolas Belil, her optometrist, who referred her to the Kellogg Eye Center.
Drs. Paulus and Belil explain that, although the chance of something like this happening is low, at times, particularly forceful movements performed in high-velocity manipulation can damage the blood vessels in the retina.
The retina is the layer of tissue that sits at the back of the eye, which contains the type of cells that convert light into neural signals that will later be sent to the brain for "decoding."
If there is bleeding inside the retina, it can result in a measure of vision loss. In the case discussed in the recent study, the woman regained her normal vision within approximately 2 months without requiring any treatment.
Some techniques may cause bleeding
Specialists found that chiropractic treatment can bring serious risks for cardiovascular health; it may damage important blood vessels. One of the most notable risks is cervical artery dissection, which can lead to stroke.
In 2014, the American Heart Association (AHA) issued a warning statement, calling for practitioners to be aware that cervical artery dissection could occur and to clearly inform their patients of the risks involved.
Forceful manipulation of the bones in the neck, Dr. Paulus points out, can cause artery walls to tear, leading to some bleeding. If a blood clot forms at the site and it later happens to become dislodged, it may end up blocking a blood vessel in the brain and causing a stroke.
This may also lead to problems with eyesight, such as double vision or the occlusion of the central retinal artery, which is the main blood vessel that carries oxygen to the nerve cells found in the retina.
Now, the case study that Drs. Paulus and Belil analyzed suggests that the motion of high-velocity neck manipulation can actually cause more direct damage to the eye.
For instance, such motions can lead to preretinal hemorrhage, which is bleeding in the vitreous humor. This is the transparent tissue that fills the eye between the lens at the front and the retina at the back.
The high-velocity technique might also result in what is known as "posterior vitreous detachment," which takes place when the vitreous humor is dislodged from the retina.
Although posterior vitreous detachment requires no special treatment and the vision problems it causes tend to improve on their own within 3 months, the event can sometimes cause serious complications. In those cases, laser treatment or surgery must be done to repair the tear.
For this reason, Dr. Paulus urges people who seek chiropractic care to alert their doctors of their choices.
He also urges chiropractors to remember that some of their patients may need them "to modify techniques" in order to avoid events such as the one reported in the case study.