Corneal edema, hyphema, and angle recession after air bag inflation

Computer Modelling Study of Volume Kinetics in Intraocular Segments Following Airbag Impact Using Finite Element Analysis

Background

We have previously studied the physiological and mechanical responses of the eye to blunt trauma in various situations using finite element analysis (FEA). In this study, we evaluated the volume kinetics of an airbag impact on the eye using FEA to sequentially determine the volume change rates of intraocular segments at various airbag deployment velocities.

Methods

The human eye model we created was used in simulations with the FEA program PAM-GENERISTM (Nihon ESI, Tokyo, Japan). Different airbag deployment velocities, 30, 40, 50, 60 and 70 m/s, were applied in the forward direction. The volume of the deformed eye impacted by the airbag was calculated as the integrated value of all meshes in each segment, and the decrease rate was calculated as the ratio of the decreased volume of each segment at particular timepoints to the value before the airbag impact.

Results

The minimum volume of the anterior chamber was 63%, 69% and 50% at 50, 60 and 70 m/s airbag impact velocity, respectively, showing a curve with a sharp decline followed by gradual recovery. In contrast to the anterior chamber, the volume of the lens recovered promptly, reaching 80-90% at the end of observation, except for the case of 60 m/s. Following the decrease, the volume increased to more than that of baseline at 60 m/s. The rate of volume change of the vitreous was distributed in a narrow range, 99.2-100.4%.

Conclusion

In this study, we found a large, prolonged decrease of volume in the anterior chamber, a similar large decrease followed by prompt recovery of volume in the lens, and a time-lag in the volume decrease between these tissues. These novel findings may provide an important insight into the pathophysiological mechanism of airbag ocular injuries through this further evaluation, employing a refined FEA model representing cuboidal deformation, to develop a more safe airbag system.

Simulation of Changes in Tensile Strain by Airbag Impact on Eyes After Trabeculectomy by Using Finite Element Analysis

Purpose

We studied the kinetic phenomenon of an airbag impact on eyes after trabeculectomy using finite element analysis (FEA), a computerized method for predicting how an object reacts to real-world physical effects and showing whether an object will break, to sequentially determine the responses at various airbag deployment velocities.

Methods

A human eye model was used in the simulations using the FEA program PAM-GENERISTM (Nihon ESI, Tokyo, Japan). A half-thickness incised scleral flap was created on the limbus and the strength of its adhesion to the outer sclera was set at 30%, 50%, and 100%. The airbag was set to hit the surface of the post-trabeculectomy eye at various velocities in two directions: perpendicular to the corneal center or perpendicular to the scleral flap (30° gaze-down position), at initial velocities of 20, 30, 40, 50, and 60 m/s.

Results

When the airbag impacted at 20 m/s or 30 m/s, the strain on the cornea and sclera did not reach the mechanical threshold and globe rupture was not observed. Scleral flap lacerations were observed at 40 m/s or more in any eye position, and scleral rupture extending posteriorly from the scleral flap edge and rupture of the scleral flap resulting from extension of the corneal laceration through limbal damage were observed. Even in the case of 100% scleral flap adhesion strength, scleral flap rupture occurred at 50 m/s impact velocity in the 30° gaze-down position, whereas in eyes with 30% or 50% scleral flap adhesion strength, scleral rupture was observed at an impact velocity of 40 m/s or more in both eye positions.

Conclusion

An airbag impact of ≥40 m/s might induce scleral flap rupture, indicating that current airbags may induce globe rupture in the eyes after trabeculectomy. The considerable damage caused by an airbag on the eyes of short-stature patients with glaucoma who have undergone trabeculectomy might indicate the necessity of ocular protection to avoid permanent eye damage.

Finite Element Analysis of Changes in Deformation of Intraocular Segments by Airbag Impact in Eyes of Various Axial Lengths

Background

We studied the kinetic phenomenon of an airbag impact on eyes with different axial lengths using finite element analysis (FEA) to sequentially determine the physical and mechanical responses of intraocular segments at various airbag deployment velocities.

Methods

The human eye model we created was used in simulations with the FEA program PAM-GENERISTM. The airbag was set to impact eyes with axial lengths of 21.85 mm (hyperopia), 23.85 mm (emmetropia) and 25.85 mm (myopia), at initial velocities of 20, 30, 40, 50 and 60 m/s. The deformation rate was calculated as the ratio of the length of three segments, anterior chamber, lens and vitreous, to that at the baseline from 0.2 ms to 2.0 ms after the airbag impact.

Results

Deformation rate of the anterior chamber was greater than that of other segments, especially in the early phase, 0.2-0.4 ms after the impact (P < 0.001), and it reached its peak, 80%, at 0.8 ms. A higher deformation rate in the anterior chamber was found in hyperopia compared with other axial length eyes in the first half period, 0.2-0.8 ms, followed by the rate in emmetropia (P < 0.001). The lens deformation rate was low, its peak ranging from 40% to 75%, and exceeded that of the anterior chamber at 1.4 ms and 1.6 ms after the impact (P < 0.01). The vitreous deformation rate was lower throughout the simulation period than that of the other segments and ranged from a negative value (elongation) in the later phase.

Conclusion

Airbag impact on the eyeball causes evident deformation, especially in the anterior chamber. The results obtained in this study, such as the time lag of the peak deformation between the anterior chamber and lens, suggest a clue to the pathophysiological mechanism of airbag ocular injury.

Effect of Head Trauma-Related Deaths on Corneal Endothelial Cell Loss in Eye Bank Donors

PURPOSE

The purpose of this study was to examine the effect of head trauma-related deaths on corneal endothelial cell density (ECD) in eye bank donors.

METHODS

This is a retrospective study of 287 corneas from donors with causes of death secondary to motor vehicle accident with sustained head trauma (n = 50), gunshot wound to the head (n = 138), fall with sustained head trauma (n = 2), and non-head-related traumatic causes of death (n = 97). Donors older than age 50 years were excluded due to concern for undiagnosed Fuchs endothelial dystrophy as a potential confounder for the cause of endothelial cell loss. Donor characteristics, ECD, and focal endothelial cell loss on specular microscopy were compared between the groups. Donors in the head trauma and nonhead trauma groups were matched by age; there were 42 age-matched donors in both groups.

RESULTS

Age and ECD were negatively correlated (Pearson correlation coefficient = -0.57). Death-to-preservation time was not significantly different between the 2 groups ( P value = 0.59). The mean ECD in the head trauma group was 2859 ± 370 cells/mm 2 and 3041 ± 464 cells/mm 2 in the nonhead trauma group. The head trauma group had a lower ECD (178 ± 70 cells/mm 2 , P value = 0.013). After matching for age, the difference in ECD between the 2 groups was -94 ± 82 cells/mm 2 ( P value = 0.26). The adjusted odds of having focal endothelial cell loss was not statistically significant ( P value = 0.50) between the groups.

CONCLUSIONS

After statistical adjustments, there were no differences between the head trauma and nonhead trauma groups.

Bilateral Angle Recession and Chronic Post-Traumatic Glaucoma: A Review of the Literature and a Case Report

Ocular trauma affects millions of people worldwide and is a leading cause of secondary glaucoma. Angle recession is the main cause of post-traumatic glaucoma after blunt eye trauma, and it is usually unilateral. The aim of this paper is to investigate the possible causes of angle recession with a bilateral presentation. Airbag activation during traffic accidents is a likely cause to be ruled out, along with repeated head or eye trauma, due to contact sports or a history of physical abuse. These aspects can aid in early detection, appropriate management, and improved outcomes for patients with ocular trauma. Finally, we report the case of a 75-year-old Caucasian man who developed a bilateral angle recession after an airbag impact, with advanced glaucoma in the right eye and ocular hypertension in the left eye. To our knowledge, this is the first case in the literature of chronic post-traumatic glaucoma probably caused by an airbag.

Air Bag-Associated Retinal Tear

We report a case of a patient seen after a minor traffic accident, showing an ocular injury due to the air-bag, with minimal corneal edema and a retinal tear. When faced with the traumatic alterations caused by an inflated air-bag, we recommended detailed exploration of the peripheral retina.

Acute corneal edema without epithelium compromise. A case report and literature review

El edema de córnea es una entidad que se produce por un gran número de causas y tiene diversas formas de presentación y diferentes grados de afección. En este artículo se reporta el caso de un hombre con edema de córnea agudo sin compromiso epitelial, en el que el cuadro clínico, el examen oftalmológico y los estudios de extensión no lograron establecer su etiología. Además, se hace una revisión de la literatura disponible respecto a todas las posibles causas de edema de córnea agudo, agrupándolas en aquellas que ocasionan el edema por lesión o inflamación epitelial o estromal, por disfunción endotelial o por un aumento en la presión intraocular.

Severe upper extremity injuries in frontal automobile crashes: the effects of depowered airbags

BACKGROUND

The purpose of this study was to determine the effects of depowered frontal airbags on the incidence of severe upper extremity injuries.

METHODS

The National Automotive Sampling System database files from 1993 to 2000 were examined in a study that included 2,413,347 occupants who were exposed to an airbag deployment in the United States.

RESULTS

Occupants exposed to a depowered airbag deployment were significantly more likely to sustain a severe upper extremity injury (3.9%) than those occupants exposed to a full-powered airbag deployment (2.5%) (P=.01). Full-powered systems resulted in an injury distribution of 89.2% fractures and 7.9% dislocations compared with depowered systems with 55.3% fractures and 44.3% dislocations.

CONCLUSIONS

Although depowered airbags were designed to reduce the risk of injuries, they appear to have increased the overall incidence of severe upper extremity injuries through a shift from long bone fractures to joint dislocations.

The Effects of Depowered Airbags on Skin Injuries in Frontal Automobile Crashes

The purpose of this study was to determine the effects of depowered frontal airbags on the incidence of skin injuries. The National Automotive Sampling System database files from 1993 to 2000 were examined in a study including 2,246,524 occupants exposed to airbag deployment in the United States. There was no significant difference between full-powered and depowered airbags, with 60.2 percent of those exposed to a full-powered deployment sustaining a skin injury versus 59.5 percent of occupants exposed to a depowered airbag (p = 0.19). Whether occupants were exposed to a full-powered airbag (1,936,485 occupants) or a depowered airbay (310,039 occupants), the majority of skin injuries were to the upper extremity and the face. Regardless of airbag power, the overwhelming majority of the skin injuries were minor (99.8 percent). There was not a significantly greater risk of injury from any source for occupants exposed to a depowered airbag or a full-powered airbag (p = 0.87). The data suggest that the implementation of depowered airbags did not affect the number, seriousness, location, or source of skin injuries.

The effects of depowered airbags on eye injuries in frontal automobile crashes

The purpose of this study was to investigate eye injuries resulting from frontal automobile crashes and to determine the effects of depowered airbags. The National Automotive Sampling System database files from 1993 to 2000 were examined in a 3-part investigation of 22 236 individual crashes. Of the 2 103 308 occupants exposed to a full powered deployment, 3.7% sustained an eye injury compared to 1.7% of the 310 039 occupants exposed to a depowered airbag deployment. Occupants were at a significantly higher risk to sustain an airbag-induced eye injury when exposed to a full powered airbag compared with occupants exposed to a depowered airbag deployment ( P = .04). Approximately, 90% of the eye injuries in full powered airbag deployments were caused by the airbag, compared to only 35% of the depowered airbag eye injuries.

A Case of Air-bag Associated Severe Ocular Injury

Air-bags have received widespread support as an effective means of enhancing automotive safety, and they are becoming more common as standard automobile equipment on many cars. Although air-bag induced ocular injuries are rare, they present a serious concern because of the possibility of permanent damage or visual impairment. To date, most reports have investigated ocular injury from high velocity motor vehicle accidents and reports of ocular injury from low speed motor vehicle accidents have been rare. We describe a patient who sustained severe ocular injury, including periorbital fracture, hyphema, vitreous hemorrhage, and choroidal rupture of the macular area, due to an inflated air-bag in a low speed motor vehicle accident.

Do motor vehicle airbags increase risk of ocular injuries in adults?

PURPOSE

This study was undertaken to evaluate the risk of eye injury in motor vehicle accidents in which airbags deploy. An attempt was made to assess the possible associations between eye injuries and eyewear in these accidents.

DESIGN

Retrospective observational case series and literature review with analysis.

PARTICIPANTS/METHODS

We conducted a literature review of 62 case reports and articles describing 110 adult cases of eye injury after deployment of an airbag and examined two Finnish accident cohorts. The fatal accident series (FAS; fatal injuries with one or more cars involved) included 121 individuals sitting behind an airbag that deployed (65 survivors), and the Airbag study (AB; nonfatal, relatively serious accidents) included 210 individuals (survivors).

MAIN OUTCOME MEASURES

The type of eye injury, eyewear, and crash dynamics were studied in each of the reviewed case reports. The fatal accident series and AB studies were analyzed to disclose the eye injuries and use of eyewear and to estimate their possible relation to deployment of airbags.

RESULTS

Analysis of the published reports revealed that airbag-induced eye injuries were not more frequently reported among wearers of eyeglasses than among nonwearers. However, open-eye injuries were reported three times more often among eyeglass wearers (P = 0.04), whereas all injuries from airbag chemicals occurred among nonwearers. With the exception of one orbital fracture with hyphema, all eye traumas (n = 7) in the FAS and AB cohorts were mild (eyebrow laceration, lid contusion, bruising). The risk of airbag-related eye injury was 2.5% for any eye injury and 0.4% for severe eye injury. In single accidents when seat belts were used, the risks were 2.0% and 0.5%, respectively. In the accidents from the FAS data no difference was observed in the risk for eye injury between survivors in incidents involving airbag deployment and incidents not involving airbags. This risk was not found to be greater among eyeglass wearers.

CONCLUSIONS

Despite reported cases in the literature, we found that the risk of severe eye injury from airbags was very low (0.4%) in fatal or relatively serious accidents. Eyewear did not seem to increase this risk but might interfere with the injury pattern.

The effects of airbag deployment on severe upper extremity injuries in frontal automobile crashes

The purpose of this study was to investigate severe upper extremity injuries resulting from frontal automobile crashes and to determine the effects of frontal airbags. The National Automotive Sampling System database files from 1993 to 2000 were examined in a study that included 25,464 individual cases that occurred in the United States. An analysis of the cases indicated that occupants exposed to an airbag deployment were statistically more likely to sustain a severe upper extremity injury (2.7%) than those occupants not exposed to an airbag deployment (1.6%) (P =.01). In particular, 0.7% of occupants exposed to an airbag deployment sustained a severe upper extremity injury specifically from the airbag. In addition, when in crashes with an airbag deployment, older occupants were at a higher risk for severe upper extremity injury, as well as occupants in crashes with higher changes in velocity.

Incidence of ocular injuries in motor vehicle crash victims with concomitant air bag deployment

OBJECTIVE

To report the incidence of ocular and nonocular trauma in patients admitted to the Henry Ford Hospital via the emergency room since 1994 after a motor vehicle crash (MVC) with and without air bag deployment.

DESIGN

A retrospective cohort study.

METHODS

The Henry Ford Hospital Trauma Registry database was reviewed for patients involved in MVCs with and without air bag deployment since 1994.

RESULTS

From 1994 to 1999, there were only seven air bag-related ocular injuries, representing 4.4% of all MVC-related ocular injuries. From 1997 to 1999, MVC-related ocular injuries with and without air bags represented 5.0% and 12.7%, respectively, of all MVC-related injuries. For that same period, the death rate and average Injury Severity Score for MVCs with air bag deployment were 3.4% and 10.75, compared with 8% and 14.5, respectively, for MVCs without air bag deployment.

CONCLUSIONS

MVC-related ocular injuries associated with air bag deployment are rare, and the incidence of ocular injuries associated with MVCs was lower when air bags were deployed.

Air bag injuries--a literature review in consideration of demands in forensic autopsies

Air bags have been implicated in saving lives and reducing morbidity associated with motor vehicle crashes since their introduction in the mid-1970s. However, there is increasing evidence showing that air bags can be a source of injury and even death in certain circumstances. As the number of air bag-equipped vehicles increases, air bag-related injuries have occurred more frequently. Thus, a greater awareness of air bag-related injuries is required in forensic autopsies. Here, we review thoroughly the literature concerning air bag-related injuries with special regard to their nature and causative mechanisms, and summarize air bag-related injuries observed in adults, children and infants.

Airbags and eye injuries: epidemiology, spectrum of injury, and analysis of risk factors

Although airbags measurably reduce the overall risk of injury to adults (including eye injury), and death from motor vehicle accidents, injuries attributed to airbag deployment have been reported. To identify reported cases of ocular trauma related to airbag deployment, a MEDLINE search from 1991 to 2000 was performed. A total of 263 injuries in 101 patients were identified. Patient demographics, details of the accident, specific ocular structures injured, and visual outcomes when available where tabulated and analyzed. The most common of these affect the eyes. Damage to the orbit and virtually every ocular and adnexal structure has been seen. Although most injuries are self-limited and do not significantly compromise vision, some result in severe, permanent visual loss. Most common is damage to anterior structures due to either blunt, contusive forces and/or chemical injury. Posterior segment trauma is less common but generally more visually devastating because of the involvement of the retina or optic nerve. Data are not available to determine whether the wearing of eyeglasses or previous intraocular surgery affects the nature, severity, or outcome of these injuries. Awareness of the spectrum of airbag-associated ocular trauma will help physicians recognize these problems early and optimize their management. Data derived from analyses of these injuries will be critical to the development of safer, more effective devices.

Ocular morbidity associated with airbag deployment: a report of seven cases and a review of the literature

PURPOSE

To review ocular injuries secondary to airbag deployment that were seen in our institution and were reported in the literature.

METHODS

Patients examined at our institution between 1997 and 2000 were evaluated for ocular injuries caused by airbags. A review of the medical literature using Medline was performed. All reports involving ocular injuries secondary to airbags were included in this study.

RESULTS

Seven cases from our medical center were identified to involve airbag-related eye injuries. The ages of the patients ranged from 4 to 73 years. Ocular injuries included corneal abrasion, corneal decompensation, corneal alkali injury, hyphema, iris sphincter tears, vitreous hemorrhage, macular retinal pigment epithelium disruption, dislocated posterior chamber intraocular lens, and commotio retinae. A review of the medical literature showed 74 cases involving 80 eyes. The ages of the patients ranged from 2 to 81 years. Males slightly outnumbered females by a ratio of 1.1 to 1.0. The speed of the vehicles ranged from 0 to 65 miles per hour, with an average reported speed of 31 miles per hour. Reported injuries ranged from mild corneal abrasions to open globes.

CONCLUSIONS

Ocular morbidity secondary to airbag deployment must be recognized as a significant risk for motor vehicle drivers and passengers. Improvements in airbag safety will include increased consumer awareness and manufacturer design modification.

Airbags and bilateral eye injury: five case reports and a review of the literature

We report five cases of bilateral eye injuries from airbag deployment in motor vehicle crashes and review the world's literature on ocular injuries associated with airbags. The cases in the literature were identified by cross-referencing Medline searches from airbags and ocular injuries. Additional cases were identified after review of references from each article in the search. An additional 89 cases from the literature were identified and are included for discussion. Patients were treated individually in a noncontrolled, nonrandomized fashion according to the nature of each injury with regular follow-up examinations in clinic. Of the 94 cases studied, 24 (27%) were bilateral eye injuries, and 15 (16%) patients were wearing spectacles at the time of the accident. The most common injuries included corneal abrasions, eyelid trauma, and hyphemas. Outcomes ranged from complete resolution of symptoms and return of normal visual acuity to primary enucleation. This report describes the wide spectrum of eye injuries that may occur after airbag deployment. We suggest a management plan for the evaluation and treatment of the ocular complications of airbag-related trauma.

Partial Dislocation of Laser in situ Keratomileusis Flap by Air Bag Injury

PURPOSE

A patient developed significant corneal complications from air bag deployment, 17 months after laser in situ keratomileusis (LASIK).

METHODS

Case report, slit-lamp microscopy, and review of the medical literature.

RESULTS

A 37-year-old woman underwent bilateral LASIK with resultant 20/20 uncorrected visual acuity. Seventeen months later, she sustained facial and ocular injuries from air bag deployment during a motor vehicle accident. Examination revealed bilateral corneal abrasions, partial dislocation of the right corneal LASIK flap, and a hyphema in the right eye. The LASIK flap was realigned, but recovery was complicated by a slowly healing epithelial defect and flap edema. One month following the injury, epithelial ingrowth beneath the LASIK flap was noted. Surgical elevation of the flap and removal of the epithelial ingrowth was performed. Eight months later, epithelial ingrowth was absent and the visual acuity was 20/40. Residual irregular astigmatism necessitated rigid gas permeable contact lens fitting to achieve 20/20 visual acuity.

CONCLUSIONS

Air bags may cause significant ocular trauma. The wound healing response of LASIK allows corneal flap separation from its stromal bed for an indeterminate time after surgery. Discussion of the possible risk of corneal trauma as part of informed consent prior to LASIK may be appropriate.

Maxillofacial fractures following airbag deployment

Maxillofacial fractures and associated lesions following airbag deployment were studied in six patients who suffered frontal or fronto-lateral car crashes. Installation of airbags in motor vehicles has reduced the morbidity and the mortality following motor vehicle accidents, but the appearance of new types of trauma directly related to airbag deployment raise questions about the potential danger of these devices when used improperly. The results of this limited study suggest that airbag injuries can be aggravated if: (1) seat belts are not worn; and (2) if the driver's chest is too close to the steering wheel as can easily happen with small people (in our study, two women). There needs to be a way of disconnecting the system.

Patterns of injury associated with automobile airbag use

The wide use of automobile airbags has undoubtedly reduced the mortality and the incidence of serious injuries from motor vehicle accidents. However, automobile airbags appear to be associated with a variety of injuries including fatal injuries, ocular injuries, upper limb and chest injuries. Further improvements in airbag design together with education of the general public in their use should help reduce airbag-related injuries.

Blow-out fracture of the orbit associated with inflation of an airbag: a case report

We report a case of blow-out fracture of the orbit in a 37-year-old woman which was caused by deployment of an airbag following collision with a stationary vehicle whilst travelling at 30 m.p.h. The fracture did not become evident until she blew her nose some hours later. She was treated with antibiotics orally and made a full and complete recovery. Therefore, refinements in the design of airbags are warranted.

Air bag-related ocular trauma

Automobile air bags have recently gained acceptance as an effective measure to reduce the morbidity and mortality associated with motor vehicle accidents. This report describes 11 cases of air bag-related ocular trauma and reviews cases previously reported in the literature, for a total of 32 patients and 39 eyes. This is the first comprehensive report on various types of ocular trauma related directly to air bag deployment. The most common type of ocular injuries seen are to the eyelids (23 patients, 28 eyes), conjunctiva (21 patients, 25 eyes), and cornea (23 patients, 28 eyes). Hyphema was frequently seen (10 patients, 11 eyes). Several serious cases of vision-threatening injuries, including retinal detachment, retinal dialysis, scleral rupture, and dislocated lens, were also reported. The following patterns were found: 55% of patients were male and 45% female; ages ranged from 2 to 81 years with a mean age of 36 years; the right eye was involved in 35% of cases, the left in 38%, and 27% were bilateral. Based on these findings, it is recommended that all patients who present with air bag-related ocular trauma undergo a complete ophthalmologic examination because the high-velocity blunt trauma causes ocular injuries that may be more serious than they initially appear. Further refinements in design and deployment need to be made to reduce the frequency and severity of air bag-related ocular injuries.

Anterior lens capsule rupture caused by air bag trauma

PURPOSE

To report a child with anterior lens capsule rupture caused by air bag inflation.

METHODS

A 10-year-old girl sustained a rupture of the right anterior lens capsule secondary to air bag deployment during a minor automobile accident. The evaluation included orbital ultrasound and orbital computed tomography.

RESULT

The right eye underwent lens aspiration with intraocular lens placement. Postoperatively, the patient did well with 20/25 best-corrected visual acuity.

CONCLUSION

Our case, in which the patient's lens capsule was ruptured by air bag inflation, illustrates that air bag deployment, even in minor low-speed accidents, can cause severe blunt trauma to the eye.

Air bag--mediated injury in the emergency department population

As the number of passenger vehicles equipped with air bags increases, the hazards associated with their use become more apparent. Certain occupants are at a greater risk of injury, depending on their size or their location in the vehicle. A predictable pattern of injury can be found; therefore a careful history and physical assessment are critical to avoid missing significant injuries.

Airbag-induced eye injuries: a report of 25 cases

OBJECTIVE

To acquire a better understanding of airbag-induced eye injuries, 25 cases are reviewed and an attempt is made to identify the causal mechanisms associated with each injury.

DESIGN AND METHODS

The National Highway Traffic Safety Administration's National Accident Sampling System for the years 1984-1994 was accessed to identify automobile accidents that included airbag deployment and injury to the ocular region. The search provided 25 such cases with detailed studies of the accident scene and medical records of the injuries. The cases were comprehensively reviewed to determine the casual mechanisms associated with each group of injuries.

RESULTS

The study determined that the injuries range from mild corneal abrasions to retinal detachment. Causation for each injury was determined and is detailed. The injuries were grouped according to location within the ocular region, and the distribution is shown.

CONCLUSIONS

Most of the injuries were induced by impact with the fully deployed airbag, but the more severe ocular trauma resulted from the actively deploying airbag striking the occupant. Thus, ocular trauma from airbags can occur in very minor impacts. Additionally, the left eye seemed more vulnerable to injury than the right. Nontethered airbags have greater inflation distances that tend to increase the probability of injury. External parameters that may also increase the severity of eye injury include an unfastened seat belt, sitting too close to the steering wheel, or wearing glasses.

Traumatic blindness after airbag deployment: bilateral lenticular dislocation

Airbags have been shown to save lives and reduce head, neck, and upper torso trauma associated with motor vehicle crashes. However, airbags have also been implicated as the source of facial and orbital injury. We report the case of a patient who suffered bilateral lenticular subluxation, anterior chamber hemorrhages, and minor facial lacerations as the result of airbag deployment.

Air bag-related corneal rupture after radial keratotomy

PURPOSE

We studied a case of air bag-associated corneal rupture in a patient who had previously undergone radial keratotomy surgery.

METHODS

The patient was struck in the right eye when his driver's side air bag inflated during a low-speed collision.

RESULTS

Inflation of the air bag resulted in rupture of the patient's right cornea. The rupture involved all but one of his old radial keratotomy wounds.

CONCLUSIONS

Patients who have undergone radial keratotomy may be at increased risk for corneal rupture caused by air bag trauma. These patients may benefit by wearing protective eyewear while driving cars equipped with air bags.

[Protective air bags in traffic accidents. Change in the injury pattern and reduction in the severity of injuries]

The effectiveness of air bags, drivers-side and passenger-side, as an additional passive safety system in motor vehicles was tested in a collective study in which 47 trauma centers in Germany participated. The inquiry was answered by 80% of 181 hospitals. The evaluation of a total of 119 air bag-protected patients involved in accidents, who were treated in German trauma centers in the year 1993 shows predominant minor injuries on the head-, cervical- and thorax-region. Some patients had superficial injuries caused by air bag in their face and chest area, such as abrasions and contusions. It is notable, that a large number of patients continue to suffer severe injuries (AIS 3+) in their lower extremities. The trend of the industry to equip more and more vehicles with air bags must be sustained. According to manufacturer statements, in 1994 already more than 60% of all mass produced vehicles in Germany will be provided with this modern passive safety system.

Ocular injuries associated with eyeglass wear and airbag inflation

OBJECTIVE

The purpose of this report is to detail three cases of serious ocular injury associated with eyeglass wear during airbag inflation following motor vehicle crashes.

DESIGN

Although there were too few cases to provide valid statistics, an attempt was made to determine if there were characteristics common to the glasses or accidents that would provide preventive information.

MATERIALS AND METHODS

The emergency room records were reviewed for a 4-year period and cases were extracted involving ocular injuries related to airbag inflation. Fourteen cases were found, and three patients were wearing glasses. These cases were studied in detail.

MEASUREMENTS AND MAIN RESULTS

All three patients sustained serious, vision-compromising ocular damage.

CONCLUSIONS

Eyeglass wear presents an additional risk factor for ocular injury during airbag inflation. Frame damage and lens shatter provide potential for both blunt and penetrating types of ocular injury.

Airbag deployment and eye perforation by a tobacco pipe

Airbags have been shown to reduce injuries and save the lives of car occupants in a crash. Like any protection system, airbags potentially introduce some new risks if no appropriate countermeasures are taken. A case of a relatively moderate frontal impact is described where the driver of an airbag-equipped car suffered a severe penetrating eye injury after the airbag deployed. Since the airbag fabric itself was excluded as an injury-producing structure, other objects such as eyeglasses, a wrist-watch, a bracelet, and a large finger ring had to be assessed. The investigation of the car interior as well as the morphologic details of the injuries to the eye and the face revealed that the most likely candidate for the injury was a tobacco pipe, which was probably being held in one hand and was broken apart by the deploying airbag and projected into the face of the driver. This case illustrates the hazard of having any rigid object between the occupant and the deploying airbag. The desirability of warning car occupants of the potential hazards which can result from today's protection systems is also discussed.