Continuing Education Activity

The consequences of ocular trauma range from complete recovery to irreversible blindness and greatly depend on the mechanism and type of injury. Understanding ocular anatomy, types of ocular trauma, and the variety of inciting events and sequelae is essential to appropriately assess, triage, manage, and ultimately reduce morbidity, blindness, and recurrence. This article will discuss the types of ocular trauma, epidemiology and risk factors, national trends, and practice patterns, as well as prognosis and prevention with an emphasis on patient counseling. Additionally, this activity will highlight the importance of the interprofessional team in evaluating, managing, and reducing the risk of visually significant ocular injuries.

Objectives:

• Describe the mechanisms of ocular trauma with their sequelae.
• Review the epidemiology of ocular trauma and resulting complications.
• Outline methods and guidelines to reduce the risk of severe ocular trauma and to appropriately triage traumatic injuries.
• Summarize recommendations and counseling strategies to reduce the risk of blindness in monocular and other high-risk patients.

Introduction

The consequences of ocular trauma range from complete recovery to irreversible blindness, with or without loss of the eye. Trauma is the most common cause of non-congenital unilateral blindness in children.[1] The US government and World Health Organization define blindness as best-corrected visual acuity worse than 20/200. Vision loss after trauma is typically defined as best-corrected visual acuity less than 20/40, or visually significant scotomas, visual field defects, or loss of contrast sensitivity.

Depending on the mechanism of injury, initial symptoms of ocular trauma vary and include pain, burning, acute loss of vision, diplopia, and physical disfigurement. This article will discuss the types of ocular trauma, epidemiology and risk factors, national trends, practice patterns, and prognosis and prevention with an emphasis on patient counseling. Understanding ocular anatomy, types of ocular trauma, and the variety of inciting events and sequelae is essential to assess appropriately, triage, manage, and ultimately reduce morbidity, blindness, and recurrence.

Issues of Concern

Types of Ocular Trauma

Chemical exposure to the ocular surface results in a variable degree of injury depending on the type of exposure. It is essential to identify the time course, degree of exposure, and pH of the causative agent. Alkali injuries, which often occur in the home, workplace, or rarely as a weapon of assault, are especially devastating with the potential to cause permanent blindness despite rapid treatment due to the ability of alkalis to penetrate deeply into the ocular tissue. On the other hand, acids denature proteins, forming a barrier to prevent further penetration. Concurrent chemical and mechanical injuries are possible, and it is important not to overlook chemical exposure during the emergency evaluation of ocular injuries.

Thermal and UV exposure can lead to severe keratitis, corneal melt, and future ocular surface dysfunction and disfigurement. Although less common, they can result from exposure to household appliances such as curling irons, UV light exposure, including UV-disinfectant lights, solar exposure, fire-related injuries, and welding or other occupational injuries. In cases of severe periocular burns or systemic burns with rapid fluid resuscitation, dramatic increases in intraorbital pressure can lead to vision-threatening orbital compartment syndrome.[2] 

Mechanical globe trauma can be characterized as either blunt or lacerating trauma. Blunt trauma is the most common type of ocular trauma and occurs after either direct or indirect impact to the globe or orbit. Common causes include motor vehicle crashes with concurrent head injury or airbag deployment, falls, physical assault, and sports-related injuries. Blunt trauma with globe contusion can result in subconjunctival hemorrhage, hyphema, commotio retinae, retinal or vitreous hemorrhage, and even retinal tears or detachment. On the other hand, lacerating globe trauma occurs with either direct contact with sharp objects or from the transmission of forces resulting in avulsion or rupture of structures.

Small subconjunctival hemorrhages in the absence of other globe injuries typically self-resolve without the need for intervention.[3] A diffuse bullous subconjunctival hemorrhage should raise suspicion for deeper globe injury, including laceration or open-globe injury.

The presence of a hyphema, or bleeding in the anterior chamber of the eye, typically results from damage to the microvasculature of the iris. Rarely a hyphema can represent blood collection from bleeding in the posterior chamber. Initial management includes eye shielding, maintaining an upright position, and prompt ophthalmology referral.[4]

Vitreous hemorrhage, or bleeding in the posterior chamber, typically presents with acute vision loss due to obscuration of the fundus.[5] Underlying retinopathy in the setting of diabetes or sickle cell disease increases the risk of vitreous hemorrhage after trauma. Vitreous hemorrhage in young and myopic patients without underlying retinopathy should raise suspicion for an underlying retinal tear.

Following a break in the retina, subsequent detachment of the neurosensory retina from the underlying retinal pigment epithelium can occur, resulting in a rhegmatogenous retinal detachment.[6] A raised, corrugated retinal appearance with subretinal fluid is classically seen on the fundus exam. Prompt surgical repair is needed to preserve vision, with improved outcomes expected when the repair is done prior to macular detachment.

Corneal abrasions are superficial injuries ranging from small epithelial defects that resolve spontaneously to visually significant lesions with subsequent development of infection, scarring, and/or astigmatism.[7] In contrast, corneal lacerations are a type of open globe injury that requires urgent surgical management.[8][9] Corneal lacerations are often accompanied by flattening of the anterior chamber, pupil peaking, and iris plugging.

Similarly, conjunctival abrasions are self-limited, in contrast with conjunctival lacerations, which may require surgical repair if large.

Scleral lacerations require surgical repair and further exploration, given the risk of penetrating globe injury. Globe rupture is an ocular emergency requiring prompt ophthalmology evaluation and surgical exploration.[10] An intraocular foreign body should be suspected based on the mechanism of injury, and CT imaging is useful to evaluate for metallic foreign bodies or suspicious patterns of globe malformation.[11]

Trauma to the orbital and periorbital structures can occur with or without an open globe injury. Understanding this intricate anatomy is important during the initial evaluation when the clinical exam must be used in conjunction with imaging to appropriately diagnose and treat patients.

In addition to eyelid lacerations, which are common traumatic injuries requiring knowledge of anatomy and meticulous repair, canalicular injuries are less obvious consequences of periocular trauma. They occur most often following assault in adults and dog bites in children.[12][13] Canalicular injuries can arise from both direct and indirect trauma with stretching of the eyelid to the point of avulsion.[14][15] Surgical repair is often required, especially in cases involving both upper and lower canaliculi, given the increased incidence of long-term epiphora and anatomical distortion. Damage to the medial or lateral canthal tendons can occur alongside canalicular injuries, especially in avulsive and lacerating injuries.

Orbital fractures frequently occur in the setting of additional facial trauma and, depending on the situation, require a multidisciplinary team of ophthalmologists, otolaryngologists, maxillofacial surgeons, and neurosurgeons. When the orbital rim is struck, the compression and transmission of intraorbital pressure can lead to a fracture at the weakest point, typically the orbital floor or medial wall, and is termed a “blowout fracture.”

A clinical exam is essential in conjunction with imaging to evaluate for signs of muscle entrapment, including eye deviation, restricted extraocular movements, bradycardia, nausea, and dizziness. Extraocular muscle entrapment requires urgent surgical correction to prevent muscle strangulation, necrosis, and further complications. Orbital roof fractures are less common and typically occur with more severe facial trauma.

Neurosurgical evaluation is required to evaluate for complications, including cerebrospinal fluid leaks, pneumocephalus, and concurrent intracranial pathology. Imaging is an important part of the initial evaluation and can suggest more severe globe injuries that require intervention. Assessment of all orbital fractures requires a thorough clinical exam to rule out globe injury, and extraocular muscle entrapment is essential and should be used in conjunction with imaging to guide treatment.

The most common cause of traumatic diplopia is extraocular muscle entrapment following an orbital fracture. In children and young adults, inferior rectus entrapment can occur without an obvious fracture on CT when an inferior fracture recoils back to its position with minimal displacement, resulting in a “trapdoor” fracture when the muscle is caught within the bony defect. Given the relative lack of other physical exam findings, many trapdoor fractures are also referred to as “white-eyed blowout fractures.”[16] EOM entrapment is a clinical diagnosis, and urgent surgical repair is indicated in most situations. In addition to entrapment, EOMs can be transected, avulsed, or retracted.[17] Understanding of orbital anatomy is needed to identify and appropriately repair such injuries.

Retrobulbar hemorrhage is a potentially vision-threatening consequence of orbital trauma that requires early diagnosis and treatment. They commonly occur in the setting of orbital fractures and can be incidentally noted on CT.[18] Significant collections due to severe trauma or systemic anticoagulation can lead to clinical findings of orbital compartment syndrome, including compressive optic neuropathy, proptosis, EOM restriction, and elevated intraocular pressure. The risk of permanent blindness is higher in retrobulbar hemorrhage in the setting of trauma compared to other etiologies.[19] Prompt decompression with a lateral orbital canthotomy and cantholysis can prevent permanent vision loss.

Epidemiology, Risk Factors, and Trends

The United States Eye Injury Registry (USEIR) collects data on ocular trauma, which is then used to identify trends and patterns to establish recommendations for prevention. A large review of patients with severe eye injuries with significant functional or structural damage from the USEIR in 1999 revealed age and gender patterns worthy of discussion. Over fifty percent of injuries occurred in patients under the age of 30 years, with an average overall male to female ratio of 4.6:1. Most injuries occurred in the home, followed by the workplace. Of the 20.5% of injuries occurring in the workplace, 96% were males, with construction as the leading occupation. Injuries affecting bystanders accounted for 20% of cases.

In this study, corneal injuries were the most common anatomical site of injury and were found in 52% of patients, followed by retinal injuries in 46%.[20] Injury from blunt objects accounted for 30% of all injuries, followed by sharp objects. Gunshot wounds and motor vehicle trauma were reported as the most frequent causes of bilateral injuries, which accounted for four percent of total injuries.

Only two percent of injuries occurred in patients wearing appropriate safety glasses or goggles, and only three percent were wearing other glasses or sunglasses, suggesting even casual eyewear provides a significant degree of protection.[20]

A retrospective cohort study of Canadian children presenting to the emergency department with eye injuries found a similar gender difference, with boys sustaining injuries three times more than girls. It has been hypothesized that risky behavior observed in boys is likely the cause for this difference. As in the overall population, injuries in children occur most frequently in the home.[21][22] An increased incidence of injuries during the summer months has also been reported, likely due to the increased time spent outdoors and without direct supervision.

Recent changes and trends in the incidence of ocular injuries have been noted in the literature. Since the 1950s, there has been a decrease in the relative incidence of workplace eye injuries, likely attributable in part to the mandatory use of protective eye devices.[20] In contrast, injuries occurring in the home have increased over time. A recent comparative cohort study found an even further increase in such injuries following the stay-at-home orders during the COVID-19 pandemic.[23] 

It was suggested that an increase in self-directed home improvement projects and other hobbies undertaken without appropriate safety regulations or eyewear has contributed to this trend. Overall, workplace injuries continue to decrease as safety protocols are implemented. At the state level, mandatory protective eyewear in adolescent sports is becoming more common and has resulted in a decrease in the incidence of head, face, and ocular injuries.[24][25]

Management & Prognosis

Management of ocular trauma depends on the initial clinical exam with attention to the mechanism of injury. A large analysis of USEIR data found that statistical predictors of ocular trauma resulting in final visual acuity <20/200 included age over 60, injury from assault, fall, gunshot, or occurring on a street or highway.[26] After systemic evaluation with verification of hemodynamic and airway stability, timely specialty consultation in such cases should be considered more urgently to expedite time to intervention. Ultimately, surgery is indicated in many cases. A large epidemiologic study using USEIR data found that 77% of severe injuries required surgery (44% requiring one and 33% requiring more than one surgery).[20]

All first responders and emergency practitioners should be educated in the basics of an ocular exam and the signs and symptoms of vision-threatening, time-sensitive injuries. In these circumstances, ophthalmic consultation should not be delayed. Studies have shown that the final visual prognosis can be improved with rapid examination and, if necessary, surgical repair. In the setting of retrobulbar hematoma, time to treatment is the most important factor in the ultimate visual outcome.[27][28]

Of all ocular trauma, injury to the posterior pole most often results in poorer visual outcomes.[20] Studies have demonstrated that vision impairment secondary to eye trauma can cause long-term personal and societal effects, including decreased quality of life, increased medical costs, and lost productivity.[29] In children, psychosocial consequences cannot be overlooked.

Prevention Strategies & Patient Counseling

The use of protective eyewear can substantially decrease the incidence of ocular injury.[30][31] Patient counseling and education aimed at assessing risk and preventing ocular trauma are essential. Occupational work with chemicals, metal, lasers, UV equipment, and other high-risk exposures require eye protection, which ideally should be supplied by employers. Workplace mandated protective eyewear can essentially eliminate the incidence of workplace injuries.[30] 

Broad recommendation and availability of protective eyewear are important now more than ever, especially with an increase in self-directed home improvement projects and a relative increase in the incidence of injuries occurring at home.[23] Eye protection for occupational purposes falls under ANSI/ISEA Z87.1. OSHA publishes specific industry standards. Emergency eyewash stations should be provided in accordance with ANSI/ISEA Z358.1.[32]

Regarding recreational activities, attitudes towards protective eyewear in sports continue to improve.[33][34][35]  The American Academy of Pediatrics (AAP) and the American Academy of Ophthalmology (AAO) released guidelines surrounding protective eyewear for youth participating in sports.[36] 

Protective eyewear should be encouraged in all organized sports, with the prescription of certified equipment as indicated based on sport and fit. The consensus recommends an initial evaluation of all athletes with a discussion of the risks involved in participation, as well as the availability of eye protection. The current standards for eye protection, including ASTM recommendations, are summarized in the following table.

Particular attention should be paid to children and adolescents with a history of eye trauma or surgery, as anatomical changes place them at higher risk for severe injury and those who are functionally monocular, defined as having a best-corrected visual acuity worse than 20/40 in the poorer-seeing eye. Participants in these categories should undergo evaluation and counseling with an ophthalmologist to further discuss the risk and potential consequences of future injury. High-risk individuals should be counseled to wear polycarbonate lenses full-time to prevent unexpected injury.

The implementation of mandatory eye protection in sports is a growing trend across the United States. Despite increased attention and policy changes, outcomes data in ocular injury prevention is slowly being assessed in support. The use of eye protection in high school lacrosse and field hockey has essentially eliminated the incidence of injury to the orbits, globes, eyebrows, and eyelids. Arguments against increased protective equipment include the risk of more direct contact and aggressive play. While some studies have shown an increased incidence of concussion, others have shown no significant increase in concussion or player-player contact injuries when protective equipment is required.[24][25][24] 

It was suggested that the increase of concussions observed in this study might be the result of increased identification and diagnosis of concussion and not a direct result of rougher play when eye protection is required. 

Activity-Specific Considerations

The AAP/AAO policy statement discusses ocular risk stratification across sports, which can be used to discuss various activities and recommendations for participation in sports activities with patients.[36] The adapted sport-specific safety stratification is displayed in the table below. Sports that involve a ball larger than the diameter of the orbit, such as soccer, globe contusion is more likely to occur with both initial findings as well as delayed complications such as angle recession, retinal tears, and detachments.[37] 

Counseling patients involved in such sports should include the importance of close follow-up and monitoring. Patients should tell all future ophthalmologists about their specific injury so that the clinical exam can be appropriately tailored to identify potential pathology before further complications develop. Boxing carries a high risk of both mild and severe ocular injuries, with a prevalence of vision-threatening ocular injuries in 58%, according to one study.[38] Additionally, it was shown that the incidence of injury increases with the time spent boxing. Sports with high-velocity balls such as golf have a lower overall incidence of ocular injuries; however, they are more severe and visually significant when injuries do occur.[39]

The Monocular and High-Risk Patients

Ophthalmologists have an essential role in the diagnosis and management of ocular injuries and prevention and counseling. The AAP and AAO have specified guidelines surrounding protective measures for functionally monocular children participating in sports.[36] Most ophthalmologists advise against participation in contact sports and strongly recommend against boxing and full-contact martial arts. It is recommended that functionally monocular athletes wear appropriate eyewear for all sports, regardless of inherent risk.

Clinical Significance

Ocular trauma is a leading cause of preventable blindness. Appropriate safety regulations are important to reduce the occurrence and severity of trauma during recreational and sports activities. Both primary care and eye care professionals need to counsel patients on proper safety precautions and protective eyewear during high-risk activities.

Enhancing Healthcare Team Outcomes

Ocular trauma is largely preventable with proper counseling and using protective eyewear during high-risk activities.[24][25] [Level 3] Ocular trauma prevention is best performed with a healthcare team. A focused patient assessment and history, including discussion of high-risk activities, are important to guide appropriate counseling and review of ocular trauma prevention strategies.[30][31][20]

High numbers of non-emergent ophthalmology consultations and follow-ups may reflect a lack of comfort among emergency physicians in managing ocular trauma. For this reason, ophthalmologists need to educate and train their colleagues to recognize, triage, and appropriately refer ocular injuries, especially in low-resource settings with limited access to specialty care.

The sequelae of ocular trauma result in various degrees of vision loss with functional deficits that affect all aspects of patients’ lives. It is often up to all healthcare team members, including ophthalmologists, to advocate for patients and ensure access to essential equipment, as well as to educate patients on their rights in the workplace.