This blog has covered many topics related to traumatic brain injury (TBI) and vision. So this is an interesting look at how TBI prevention can actually place the eye at risk.
Everyone knows airbags were developed mostly to prevent drivers and passengers from striking the steering wheel or dashboard in head-on auto collisions. Seat and shoulder belts were simply not enough.
Airbags have reduced the amount of serious brain injuries and deaths from motor vehicle accidents. This is a good thing, but airbags can also cause injuries, especially to the eye.
In order for an airbag to work it must open explosively, before the severe whiplash jerks the head forward. The airbag frequently comes into direct contact with the eyes- there is not even enough time to blink.
Sometimes the injuries are minor, but they can be vision threatening.
Patients often complain of immediate redness, pain, and decreased vision after airbag deployment. The direct force of the bag can damage the front surfaces of the eye, in particular the cornea and conjunctiva. Corneal abrasions are common and need to be evaluated. The impact can result in bleeding in the front of eye (called a hyphema) or the back of the eye (called a vitreous hemorrhage). These are serious injuries and need immediate evaluation and treatment. Of even greater concern- airbag blunt force can cause silent retinal tears which can later lead to retinal detachment and loss of vision.
In addition, a chemical dispersant is rapidly released into the air as the bag deploys. This helps lubricate the bag for rapid expansion. Passengers frequently notice a fine white or grey powder, it has a distinct smell.
Also, air from inside the bag can escape from small openings in the bag itself. This mix of chemicals frequently includes sodium hydroxide which is chemically toxic to the eye.
If victims get powder in their eyes, the best initial treatment is irrigation (pouring water in the eyes). But chemical injuries should be evaluated by an ophthalmologist.
Car accident victims are frequently overwhelmed at the time of an accident and are simply unaware of ocular injuries. If an airbag goes off in an auto accident, the occupants are definitely aware, it’s dramatic. I’m sure many people reading this blog recall the experience.
The take-away message is to ask individuals who have experienced airbag deployment about their eyes. If someone actually asks (in a standard emergency room visit it generally doesn’t come up), then the answer is often yes, the eyes are affected. Most of the time the injury is going to be minor and self-healing, but these victims need a complete eye exam. It may not be an immediate emergency, but hidden damage can occur. If the eyes are red and irritated, then they definitely need to be seen. I have seen many eye airbag injuries in my busy ophthalmology practice and always ask car accident victims if the airbags went off.
Airbags may save lives, but they can injure eyes. That’s the take home message. The head gets cushioned but the eyes can get popped. The first step, ask the victims about the airbag and inquire about the eyes. If there is any question, a thorough eye exam is indicated.