Ocular related sports injuries

Introduction

Ocular injuries occur frequently in sports and are a source of significant morbidity. Sports-related injuries are a common complaint in the emergency department,^1,2 and account for a significant percentage of all penetrating eye-injuries.³ They disproportionally affect younger males, likely due to high participation rates in sports amongst this population. Different sports carry variable ocular risks which are dependent on many factors: the level of contact involved, the type of equipment involved (which can cause blunt or penetrating trauma),^4,5 and the size, velocity and weight/density of the game-object. These each play important roles in the level of severity of the ocular injury. The sports with the highest incidence of ocular injuries differ between countries and regions, a reflection of the variable popularity in those areas. In the United States the most common sports associated with ocular injuries include basketball, baseball, softball, football, racquetball and soccer.⁶ In Brazil, indoor and outdoor soccer are most common causes of ocular injury⁷, and in Finland, floorball is the leading culprit.⁸

It is estimated that 90% of all sport-related ocular injuries are preventable with suitable eye protection. A joint policy statement by the American Academy of Pediatrics and American Academy of Ophthalmology strongly advocates for the use of protective eyewear for all participants in sports in which there is risk of eye injury.⁹ Still, more than 42,000 annual sport- and recreation-related eye injuries are reported in the US, ¹⁰ with over 20,000 of those in the pediatric population,² despite repeated calls over the past 40 years for increased eye-protection in certain high-risk sports.

Ocular Injury Mechanisms

Sport-related eye injuries can affect the globe, the surrounding soft tissues (including the optic nerve), and the orbital bony structure.¹⁰

Open globe injuries

Open globe injuries include a full thickness break in the cornea and/or sclera of the globe (Figure 1). They compose a small minority of all sport-related ocular injury, but carry a grave visual prognosis.¹¹

Figure 1.

Intraocular contents have extruded onto the lower lid of a patient with a ruptured globe (full thickness break in the inferotemporal cornea). Photo courtesy of Benjamin Lin, MD.

Any suspected open globe injury requires urgent ophthalmological evaluation and surgical intervention. Patients often complain of severe pain and reduced vision. Initial findings can be dramatic, such as globe deformation, or more subtle, such as a small corneal or scleral laceration.

Open globe injuries are further classified into rupture, penetration (single full-thickness laceration of the globe) or perforation (two full thickness lacerations of the globe corresponding to entry- and exit-wounds). The pathogenesis of a ruptured globe differs from a penetrating or perforating injury. In a rupture, the forces from a blunt trauma to the globe lead to an increase of pressure within the globe. This causes the sclera to expand equatorially, producing corneo-scleral stress that leads to a full thickness break in the globe.¹² Breaks arise in areas where the structural integrity of the globe is weakest: at the equator behind the extraocular muscle insertions and at the corneo-scleral junction. Penetrating and perforating injuries are usually caused by a sharp object or missile and localized to the site of impact. These injuries are most commonly seen in the visualized anterior half of the globe. Such injuries usually stem from trauma from smaller sports-related equipment or equipment with sharp edges such as paintball pellets,¹³ a badminton shuttlecock,¹⁴ or darts¹⁵, however they can also be secondary to broken materials, including the patient’s own broken glasses.^16–18 These small pieces may also be confined within the globe, an entity that is referred to as a retained intraocular foreign body. These must be ruled out before pursuing surgical intervention. Imaging studies (CT orbits without contrast with fine cuts for presumed metallic foreign bodies; MRI orbits without contrast for non-metallic foreign bodies) are very a critical component to fully evaluate for this.

Prompt evaluation and treatment is critical to reduce risk of infection and to prevent further loss of vision. In the time between injury and evaluation the patient should be given an eye shield to prevent additional pressure of the globe possibly furthering globe content expression through the break. Even with prompt surgical repair visual prognosis of such injuries is grave and complications can arise after surgery, including cataract, retinal detachment, endophthalmitis, and sympathetic ophthalmia.¹¹ The Ocular Trauma Score (OTS),¹⁹ which is used to predict the visual outcome of patients after open globe ocular trauma, is an effective tool (80% predictive) to counsel patients and their families and to manage their expectations for visual recovery. It also aids the clinician with surgical decision making before pursuing complex, costly interventions, particularly in resource-limited settings.

Closed Globe Injuries

Non-penetrating ocular injuries can damage all the structures of the globe. The mechanism of injury can be either player-to-player contact or player-to-equipment contact. These injuries are addressed next.

Eyelid lacerations

Ocular adnexal wounds are not uncommon¹ and can range from simple lacerations to complex eyelid margin avulsion and canalicular injuries. Any such injury should raise suspicion for associated globe injuries. Lacerations involving the lid margin (Figure 2) or canalicular system, or injuries in which prolapsed orbital fat is identified should be referred for specialized ophthalmologic evaluation and surgical treatment. Such injuries might be later complicated by ptosis, epiphora and eyelid malposition, if not appropriately addressed.

Figure 2.

An 8 ball hyphema and diffuse subconjunctival hemorrhage is noted in this patient who presented after blunt trauma to the eye (A). Photo courtesy of Marissa Shoji, MD.

A hyphema can be seen layering in the bottom of the anterior chamber of this patient with a history of previous cataract surgery and placement of a glaucoma drainage implant (B). Photo courtesy of Raquel Goldhardt, MD.

Corneal abrasions

This may be the most common of the ocular injuries, occurring when inadvertent finger-eye contact is made during playing a myriad of sports.^6,16,20–23 Any break in the superficial corneal epithelium will lead to immediate severe pain, foreign body sensation and reflexive tearing. Corneal abrasions require prompt ophthalmic evaluation to rule out other injuries, including but not limited to a corneal perforation/penetration. Staining the cornea with fluorescein and subsequently shining Cobalt blue light aids in detecting such abrasions as defects in the corneal epithelium fluoresce green (Figure 3). This basic eye exam can even be performed on the sidelines at the time of injury. Topical anesthesia drops used as part of the eye evaluation usually give rapid relief and further solidifies the diagnosis. Treatment goals include prevention of infection, controlling pain and expediting healing. This is achieved through the use of topical antibiotics, in either drop or ointment form. Larger abrasions may benefit from covering the cornea either with a bandage contact lens or patching the eyelids shut. Pain can be managed by using non-steroidal anti-inflammatory drugs (NSAID) and occasionally topical cycloplegics. Topical NSAIDs should not be used for more than a few days as they can be associated with corneal toxicity.²⁴ Similarly, long term use of topical anesthetic for pain control is also toxic to the cornea and prevents healing.

Figure 3.

A corneal epithelial defect is fluorescing after cobalt blue light is being shone on an eye that has been stained with fluorescein. Photo courtesy of Alison Bozung, OD.

Athletes who had prior LASIK surgery warrant closer evaluation, as ocular trauma can cause dislocation or loss of the corneal epithelial flap created in the refractive surgery.^25,26 Such injuries can lead to significant and unexpected refractive errors, so the use of protective eye protection in this cohort of athletes is highly advisable.

Subconjunctival hemorrhage

A subconjunctival hemorrhage can occur with any kind of ocular trauma² and is the manifestation of injury/rupture of a conjunctival blood vessel and subsequent accumulation of blood in the subconjunctival space. The condition is mainly cosmetic and presents as areas of redness on the patient’s sclera. Patients do not usually have changes in vision or experience pain. No treatment is needed. Large subconjunctival hemorrhages that cover the majority of the sclera should be evaluated by an ophthalmologist as they may mask an underlying occult rupture or perforation/penetration of the globe.

Hyphema

As described earlier, blunt ocular trauma causes the eye to expand equatorially. In the case of hyphema, the subsequent shearing forces can cause significant damage inside the globe. Iris and/or ciliary body vessels can rupture and bleed into the anterior chamber, referred to as a hyphema (Figure 4). Hyphema can vary in severity from floating red blood cells in the anterior chamber to complete filling of the anterior chamber with blood (the so called “8-ball hyphema”). Examination of the patient can show layering of blood in the anterior chamber. Complications of hyphema are vast and sight threatening,²⁷ so management by an ophthalmologist is prudent. Hyphemas can be complicated by elevated intra-ocular pressure (IOP) from a variety of mechanisms, the most common being a blockage of the trabecular meshwork which drains aqueous from the eye. Secondary bleeding can occurs as an initially clotted vessel can re-rupture. Very high pressures in the eye leads to an entity known as corneal blood staining where red blood cells are pushed into the cornea from the anterior chamber. Prolonged elevations in intraocular pressure can lead to optic nerve atrophy.²⁷ Acute management is directed towards accelerating blood absorption while also monitoring and controlling intraocular pressure. Bed rest and eye-protection are commonly advised. Topical treatments include mydriatics, cycloplegics, and steroids. Mydriasis and cycloplegia provide a theoretical benefit of immobilizing the iris and thereby reducing the risk of secondary bleeding²⁸ and controlling pain that may arise from spasm of the iris. Topical steroids have also been shown to reduce the rate of secondary bleeding²⁹ while also controlling intraocular inflammation. In severe cases the patient may need a surgical procedure (anterior chamber wash out) to clear the blood from the anterior chamber. Return to play or practice should be guided by an ophthalmologist.

Figure 4.

A full thickness lower lid laceration is demonstrated in this patient with a history of blunt trauma to the face (A) and after surgical repair (B). Photo courtesy of Marissa Shoji, MD.

Posterior segment injuries

The same pathophysiological mechanisms described so far can cause significant posterior chamber injuries. Traumatic cataract, commotion retinae (bruising of the retina), retinal breaks, retinal detachment³⁰ and choroidal breaks³¹ are only a few manifestations of ocular trauma.¹² Court-side examination of posterior chamber injury are not feasible as they require a dilated fundus examination, therefore any complaint of visual disturbance or changes, or complaints of seeing flashes and floaters after ocular trauma should be promptly referred to an ophthalmologist for a complete and thorough evaluation.

Retrobulbar Hematoma

Bleeding within the confines of the orbit can result in orbital compartment syndrome (OCS), leading to vision loss via increased orbital pressure that can cause occlusion of the central retinal artery and/or can directly compress the optic nerve or can compress the orbital vasculature.³² Such acute increase in orbital pressure is an ophthalmological emergency, as permanent ischemic changes begin within 60 minutes of visual dysfunction.³² While most retrobulbar hemorrhages occur as a consequence of significant craniofacial trauma, it can also occur with mild trauma, or even spontaneously in the setting of chronic anti-coagulation.

Definite diagnosis of OCS requires observation of reduced perfusion of the optic nerve or retina through a dilated fundus examination, a challenging exam to perform on site of the injury. Initial evaluation showing relative proptosis, difficulty opening the eyelids using finger pressure and a relative afferent pupillary defect should raise the possibility of OCS and serious consideration must be given to performing a lateral canthotomy and inferior cantholysis, thereby reliving the OCS and allowing for rapid reduction of orbital pressure.³³ It is also important to avoid blood thinners at the time of the incident in these patients (eg. avoid NSAIDS for pain management) and attempt to reverse anticoagulation, if possible.

Traumatic optic neuropathy

Damage to the optic nerve secondary to head trauma can cause traumatic optic neuropathy (TON), where the optic nerve is compromised by either direct or indirect trauma.³⁴ In particular, the optic nerve is fixed to the bone when traversing the optic canal, thus any deformation specifically within or near the optic canal can cause grave optic nerve insult. Patients usually present with immediate visual deterioration, however, delayed cases have been reported. In a large series of pediatric TON, sport-related trauma was second only to trauma from vehicle accidents.³⁵ A brief exam in the field will likely show a relative afferent pupillary defect. These patients should be referred for immediate ophthalmological evaluation. In most cases the optic nerve appears normal, suggesting damage to the intracranial, intra-canalicular or posterior orbital parts of the optic nerve, however, some cases may show signs of optic nerve head swelling. Treatment is controversial and various medical and surgical modalities have been reported, ranging from high dose intravenous steroids to surgical optic canal decompression. Unfortunately over 50% of the patients do not recover vision.³⁴

Orbital fractures

Orbital fractures, commonly of the orbital floor or medial orbital wall, composes almost 10% of all sport-related ocular injuries (Figure 5).¹ Trauma can result from impact with sporting equipment, contact with other players, or from falls (the latter being seen in non-contact sports such as jogging and cycling).³⁶ Trauma is usually the result of a blunt injury with a piece of equipment that is wider than the orbital socket (approximately 4 cm). Two theories have been posited to explain the pathophysiology of traumatic orbital fractures: The hydraulic theory suggests that retropulsion of the globe secondary to a large outside force increases the intraorbital pressure, which is distributed to the orbital walls, creating a fracture; The buckling theory suggests that force is applied directly to the inferior orbital rim, then transmitted along the orbital floor and causes a fracture.³⁷ The location of most orbital fractures are along the bony walls that are thinnest. The orbital floor (particularly the roof of the infra-orbital canal) is the thinnest area of the orbital walls followed by the lamina papyracea in the medial wall.³⁸ Sport-related trauma is often not confined to the orbit, and involves complex facial fractures. A recent study found that the most common type of fracture in sport-related injuries was the zygomatico-maxillary complex fracture.³⁶ Orbital fractures can present with bruising, subconjunctival hemorrhage and periorbital ecchymosis, but also with enophthalmos (sunken appearance of globe), orbital emphysema, restricted eye movements from entrapped or bruised extraocular muscle and anesthesia in the infraorbital nerve distribution. Treatment is governed by symptoms: orbital fracture repair is generally undertaken if an extraocular muscle is entrapped, over 50% of the orbital floor is involved, or if the patient has cosmetically significant enophthalmos (>2 mm difference in projection of one globe from another).³⁹ One type of fracture seen in children, the trapdoor fracture, requires prompt surgical repair. In these types of fractures, the orbital floor buckles, allowing for the inferior rectus muscle to herniate through the fracture. Shortly thereafter the floor snaps back into place and entraps the muscle. These patients experience nausea, pain, and bradycardia as they supraduct their eyes. Looking up leads to a tug on their tethered inferior rectus muscle and activates the oculocardiac reflex (cranial nerve V to cranial nerve X). Failure to address this fracture quickly can lead to ischemia and fibrosis of the inferior rectus muscle and ultimately intractable diplopia.⁴⁰

Figure 5.

CT scan of a 14 Year old female who was struck in the left orbit by a softball, showing orbital wall fractures. (A) Coronal view: Left medial and floor fracture. Notice fracture propagation along the roof of the infra orbital canal and lamina papyracea. White arrow points to intra-orbital air. (B) Axial view better depicts the medial wall fracture. (C) Sagittal view allows better appreciation of the depressed orbital floor fracture.

Immediate orbital fracture repair is advocated in trapdoor fractures and in cases with significant vertical globe displacement.⁴¹ Controversy exists over timing of orbital fracture repair. Advocates of early repair (within 2 weeks of fracture) point to less post-traumatic soft tissue scarring and early reversal of tissue compression,⁴² while supporters of late repair show that many of isolated orbital fractures do well with conservative treatment and may not need surgical repair at all.⁴¹

Prevention

More than 30,000 sports-related ocular injuries are seen in emergency rooms in the USA annually,^1,2 most in males during late-teens and early 20s and some lead to permanent vision loss. Appropriate eye protection can reduce the risk of eye injury by 90%, however only a small minority of sport participants wear adequate eye protection.³

Prevention of ocular injuries by requiring eye-protection is extremely effective in sports that mandate such wear. The United States Squash Racquets Association required all participants in national championships to wear goggles that protect the eye from contact with a squash ball of up to 90 mph. No reports of significant ocular injuries are reported when such protection is worn during squash or racquetball.⁴³ The national hockey league mandated half visors in 2013, and a steep decline in ocular injuries followed.⁴⁴ Eye protection made of polycarbonate lenses, which can provide 20 times more protection than regular glasses, can therefore significantly reduce sports-related ocular injuries.

Other prevention strategies rely on making the surroundings safer for participants. In a study from Singapore, 90% of orbital fractures secondary to cycling occurred in non-designated cycling tracks in neighborhoods,³⁶ so increasing the availability of designated cycling tracks can possibly reduce such injuries. Targeted ocular injury prevention programs have been shown to reduce morbidity, and should be further implemented and encouraged.

In summary, sports-related ocular injuries remain a source of significant morbidity even though simple prevention methods are available. Eye protection should be encouraged as it can eliminate or reduce the severity of the majority of ocular injuries. Prompt ocular examination and treatment, as well as timely referral to an ophthalmologist can speed recovery and reduce the long term visual sequela of such injuries.