Automobile air bags: friend or foe? A case of air bag-associated ocular trauma and a related literature review

Head and Neck Airbag Penetrating Injuries

BACKGROUND

Airbags have significantly decreased fatalities in frontal vehicle accidents, but their deployment can lead to more severe injuries and rarely death. The authors present a case of a penetrating injury causing tissue loss in the left cheek, an "explosion" of the zygomatic arch, and facial nerve damage, discussing the management in the contest of literature examining similar injuries in the head and neck region.

MATERIALS AND METHODS

Reviewing English literature from 1995 to 2023, 9 patients experienced severe airbag-related penetrating head and neck injuries, in 3 cases resulting in death. In addition, we describe the case of a young male reporting a deep cheek laceration with facial nerve damage, tissue loss, and comminuted maxilla-zygomatic fracture; 48 hours after trauma, he underwent surgical reconstruction using a bilobed flap, direct suture of the resected masseter muscle, closed reduction of the comminuted zygomatic arch fracture, and direct neurorrhaphy of the lacerated facial nerve.

RESULTS

Five months after surgery, facial nerve function recovery was observed. Mouth opening was restored, but a mixed low-medium hearing loss persisted for high frequencies. In another case marginal nerve damage was reported, but management is not described.

CONCLUSION

The use of seat belts and airbags has led to a significant reduction in the incidence of facial fractures and fatalities after motor vehicle accidents, but at the same time, in some cases, complex facial trauma and/or penetrating injury can be observed. In case of suspected or certain facial nerve damage, it is mandatory to perform exploration and eventual reconstruction within 72 hours.

A case of retinal detachment resulting from air bag deployment

ABSTRACT A motor vehicle accident (MVA) can result in death or serious injury to the driver and passengers in case the airbags are not deployed. There are, however, several reasons why an airbag can injure a passenger even when there is no accident involved. A 41-year-old female patient who suffered facial bone fractures and an retinal perforation after her air bag deflated during a minor car accident. The complaints of the patient on admission to the emergency department (ED) were facial pain, swelling and redness in the eye. Orbital CT imaging revealed fragmented fracture line displaced into the maxillary sinus at the floor of right orbit, posttraumatic changes in preorbital skin and In the right globe vitreous, an appearance thought to belong to hyperdense hemorrhage. The patient was taken to emergency operation due to corneal perforation in the right eye. All patients who present with air bag-related ocular trauma should undergo a complete ophthalmologic examination because ocular injuries that may be more serious than they initially appear.

Corneal endothelial decompensation due to airbag injury

PURPOSE

We report a case of localized endothelial decompensation due to airbag deployment during a motor vehicle accident.

CASE REPORT

A middle-aged woman involved in a motor vehicle accident presented with diminution of vision in left eye. Initial ocular examination revealed corneal abrasion, localized central corneal edema and mild anterior chamber reaction. An anterior-segment ocular coherence tomography (AS-OCT) revealed focal paracentral corneal edema. Patient was managed with lubricating eye drops and antibiotic steroid combination. Significant endothelial cell loss compared to right eye was noted on specular examination. At one- month follow-up, visual acuity recovered to 6/6 but the pleomorphism and polymegathism persisted.

CONCLUSION

Airbag-related localized corneal endothelial decompensation is a less known occurrence. This case emphasizes on the fact that serial monitoring of endothelial counts and conservative management can prove beneficial in such scenarios.

Facial injuries: Triage and applying damage control principles

Facial trauma varies widely in its severity and is also frequently associated with other injuries which can make prioritisation of injuries difficult. An effective method of triage is important to ensure this. This article describes one such approach and discusses the application of damage control principles to facial injuries. Both these issues commonly impact on the management of multiply injured patients with coexisting facial injuries during the initial stages of resuscitation or soon afterwards. Understanding facial trauma is based in part, on parallels with orthopaedic trauma.

Vehicle occupant restraint systems impact on eye injuries: a review

Vehicle occupant trauma to the eyes and associated facial structures has evolved rapidly in conjunction with safety-oriented vehicle design, including restraint systems. Trends vary worldwide with culture, personal factors, vehicle safety equipment, and the traffic environment-including physical, legislative, and enforcement. Wearing safety belts is essential to occupant protection. Airbags were designed as a supplement to protect the head from hard surfaces in frontal crashes, not as a primary countermeasure. Even where vehicle fleets are new with high airbag prevalence, but safety culture and knowledge of restraints is less than robust, injury attributable to not wearing seatbelts is frequent, especially in countries where high-powered vehicles are prevalent. Upper bodies of rapidly forward-moving unrestrained occupants collide with rearward-accelerating airbags. Airbag deployment produces injuries such as corneal abrasions, alkali burns, and the effects of globe compression.

Constitutive behavior of ocular tissues over a range of strain rates

The constitutive behavior of bovine scleral and corneal tissues is measured in tension and compression, at quasi-static and moderate strain rates. Experiments are conducted at strain rates up to about 50 strain per second by a pneumatic testing system developed to overcome noise and measurement difficulties associated with the time dependent test of low impedance materials. Results for the tissues at room and the natural bovine body temperatures are similar and indicate that ocular tissue exhibits nonlinear stiffening for increasing strain rates, a phenomena termed rate hardening. For example, at a tensile strain rate of 29/s, corneal tissue is found to develop 10 times the stress that it does quasi-statically at the same strain. Thus, conventional constitutive models will grossly underpredict stresses occurring in the corneo-scleral shell due to moderate dynamic events. This has implication to the accuracy of ocular injury models, the study of the stress field in the corneo-scleral shell for glaucoma research and tonometry measurements. The measured data at various strain rates is represented using the general framework of a constitutive model that has been used to represent biological tissue mechanical data. Here it is extended to represent the measured data of the ocular tissues over the range of tested strain rates. Its form allows for straightforward incorporation in various numerical codes. The experimental and analytical methods developed here are felt to be applicable to the test of human ocular tissue.

Sensorineural Hearing Loss due to Air Bag Deployment

Deployment of the air bag in a passenger vehicle accident rarely causes otologic injuries. However, sensorineural hearing loss induced by air bag deployment is extremely rare, with only a few cases reported in the English literature. A 38-year-old man involved in a traffic accident while driving his car at 40 km/hour presented with right sensorineural hearing loss and tinnitus, without associated vertigo. Pure-tone audiometry demonstrated elevated thresholds of 30 dB and 25 dB at 4 kHz and 8 kHz, respectively, on the right side. Air bag deployment in car accidents is associated with the risk of development of sensorineural hearing loss.

Simultaneous injuries to both eyes in traffic accidents

BACKGROUND

In traffic accidents, eye injuries occur as isolated or with polytrauma. They may involve just one eye, but simultaneous injuries to both eyes do happen occasionally. The aim of our paper was to reveal the risk factors, in an effort to reduce the number of such accidents and to prevent bilateral ocular damage.

METHODS

All patients hospitalized at the Clinic of Eye Diseases, Clinical Center of Serbia, Belgrade, due to traffic accidents with bilateral eye injuries in a period of 9 years from the beginning of 2000 to the end of 2008 were analyzed.

RESULTS

In this 9-year period, a total of 36 patients were hospitalized and treated for bilateral ocular injury (72 eyes). There were 23 males among them, the male-female ratio being 1.8:1. Mean age was 33.9 years. The occupations of injured persons were the following: the most common were workers--15, followed by clerks--seven, while less common were pupils, students, pensioners and housewives-three of each of them, and farmers--two. Front-seat passengers were the most common among the injured--20 (55.6%), then drivers--15 (41.7%), with only one passenger from the back seat on the right side (2.7%). As many as 33 (91.7%) of them failed to fasten their seat belts, while 18 (50.0%) were drunk. Penetrating bulbar injuries or eyeball ruptures were predominant--66.7%, while blunt injuries were found in only two (2.8%) eyes in one single person; but in 22 cases (30.5%) there was adnexal damage, too. Visual acuity at discharge and subsequent controls was as follows: amaurosis in 21 (29.2%), less than 0.3 in nine (5.6%), 0.4 and better in 42 (58.1%), and normal visual acuity of 1.0 in 28 patients (38.3%).

CONCLUSION

The major risk factors for getting bilateral eye injuries in traffic accidents proved to be: sitting in the front car seats, not fastening the seat belt and alcohol intoxication. Prevention of these risk factors would result in a decrease in such a large number of bilateral eye injuries.

Airbag-induced corneal flap

PURPOSE

To describe a case of airbag-induced corneal flap in a previously normal cornea.

METHODS

Case report.

RESULTS

A 27-year-old woman presented with complete loss of vision in her left eye following a road traffic accident which involved airbag deployment. There was no previous ocular history. Examination revealed a large corneal flap of 6mm in diameter, extending to the depth of anterior stroma. This was accompanied by a traumatic optic neuropathy. One month follow-up revealed complete reattachment of the corneal flap.

CONCLUSIONS

This is the first reported case of a corneal flap induced by airbag deployment in a cornea with previously normal architecture.

Air bag-associated burn

Burns due to the deployment of air bags have been occasionally described in recent years. Most reports are about injuries in the USA. However, there have been few reports of this type of injury in Australia. This case report details such an injury that took place in a road traffic accident in Melbourne, Australia.

Corneal abrasion and alkali burn secondary to automobile air bag inflation

A 59-year-old woman self presented to the emergency department with a painful right eye following a motor vehicle accident. She had reduced visual acuity and the eye had an alkaline pH with complete corneal uptake of fluorescein. Diagnosis of corneal abrasion and alkali burn to her right eye secondary to inflation of a driver's automobile airbag was made. The eye was irrigated with normal saline. Such injuries, although rare, can easily be identified within the emergency department by the history of exposure, evidence of facial injuries or burns, and an alkaline pH in the inferior cul-de-sac of the eye. Early detection and management with ophthalmology review is therefore imperative to prevent irreversible visual impairment.

Airbag induced corneal ectasia

PURPOSE

To report a case of airbag induced corneal ectasia.

METHODS

Case report.

RESULTS

A patient 3 years post-LASIK developed bilateral corneal ectasia worse in the right eye following airbag deployment in a road traffic accident. At last follow up, best corrected vision was 20/40 with -4.00/-4.00 x 25 in the right eye and 20/25 with -1.25/-0.50 x 135 in the left eye.

CONCLUSIONS

This is a rare presentation of trauma induced ectasia in a patient post-LASIK. It is possible that reduction in biomechanical integrity of the cornea from prior refractive surgery contributed to this presentation.