Ocular Trauma

OCULAR TRAUMA

Ocular trauma is the leading cause of blindness among children and young adults, especially male trauma victims. The most com-mon circumstances of ocular trauma are occupational injuries (eg, construction industry), sports (eg, baseball, basketball, racket sports, boxing), weapons (eg, air guns, BB guns), assault, motor vehicle crashes (eg, broken windshields), and war (eg, blast fragments).

For the nonophthalmic practitioner, initial intervention is performed in only two conditions: chemical burns, for which irrigation of the eye with normal saline solution or even plain tap water must occur immediately, and a foreign body, for whichabsolutely no attempt is made to remove the foreign material, small or big, or apply pressure or patch to the injured eye. The eye must be protected using a metal shield, if available, or a stiff paper cup (Fig. 58-17). All traumatic eye injuries should be properly shielded.

Assessment and Diagnostic Findings

A thorough history is obtained, particularly assessing the patient’s ocular history, such as preinjury vision in the affected eye or past ocular surgery. Details related to the injury that help in the diag-nosis and assessment of need for further tests include the nature of the ocular injury (ie, blunt or penetrating trauma), the type of activity causing the injury to determine the nature of the force striking the eye, and whether onset of vision loss was sudden, slow, or progressive. For chemical eye burns, the chemical agent must be identified and tested for pH if a sample is available. The corneal surface is examined for foreign bodies, wounds, and abra-sions, after which the other external structures of the eye are ex-amined. Pupillary size, shape, and light reaction of the pupil of the affected eye are compared with the other eye. Ocular motil-ity, which is the ability of the eyes to move synchronously up, down, right, and left, is also assessed.

Medical Management

SPLASH INJURIES

Splash injuries are irrigated with normal saline solution before further evaluation. In cases of ruptured globe, cycloplegic agents (ie, agents that paralyze the ciliary muscle) or topical antibiotics must be deferred because of potential toxicity to exposed intra-ocular tissues. Further manipulation of the eye must be avoided until the patient is under general anesthesia. Parenteral, broad-spectrum antibiotics are initiated. Tetanus antitoxin is adminis-tered, if indicated, as well as analgesics. (Tetanus prophylaxis is recommended for full-thickness ocular and skin wounds.) Any topical medication (eg, anesthetic, dyes) must be sterile.

FOREIGN BODIES AND CORNEAL ABRASIONS

After removal of a foreign body from the surface of the eye, an antibiotic ointment is applied, and the eye is patched. The eye is examined daily for evidence of infection until the wound is com-pletely healed.Contact lens wear is a common cause of corneal abrasion. The patient experiences severe pain and photophobia (ie, ocular pain on exposure to light).

Corneal epithelial defects are treated with antibiotic ointment and a pressure patch to immobilize the eye-lids. It is of utmost importance that topical anesthetic eye drops are not given to a patient for repeated use after corneal injury be-cause their effects mask further damage, delay healing, and can lead to permanent corneal scarring. Corticosteroids are avoided while the epithelial defect exists.

Penetrating Injuries and Contusions of the Eyeball

Sharp penetrating injury or blunt contusion force can rupture the eyeball. When the eye wall, cornea, and sclera rupture, rapid de-compression or herniation of the orbital contents into adjacent sinuses can occur. In general, blunt traumatic injuries (with an increased incidence of retinal detachment, intraocular tissue avul-sion, and herniation) have a worse prognosis than penetrating in-juries. Most penetrating injuries result in marked loss of vision with the following signs: hemorrhagic chemosis (ie, edema of the conjunctiva), conjunctival laceration, shallow anterior chamber with or without an eccentrically placed pupil, hyphema (ie, hem-orrhage within the chamber), or vitreous hemorrhage.

Hyphema is caused by contusion forces that tear the vessels of the iris and damage the anterior chamber angle. Preventing re-bleeding and prolonged increased IOP are the goals of treatment for hyphema. In severe cases in which patient compliance is ques-tionable, the patient is hospitalized with moderate activity re-striction. An eye shield is applied. Topical corticosteroids are prescribed to reduce inflammation. An antifibrinolytic agent, aminocaproic acid (Amicar), stabilizes clot formation at the site of hemorrhage. Aspirin is contraindicated.

A ruptured globe and severe injuries with intraocular hemor-rhage require surgical intervention. Vitrectomy is performed for traumatic retinal detachments. Primary enucleation (ie, com-plete removal of the eyeball and part of the optic nerve) is con-sidered only if the globe is irreparable and has no light perception. It is a general rule that enucleation is performed within 2 weeks of the initial injury (in an eye that has no useful vision after sus-taining penetrating injury) to prevent the risk of sympatheticophthalmia, an inflammation created in the fellow eye by theaffected eye that can result in blindness of the fellow eye.

Intraocular Foreign Bodies

A patient who complains of blurred vision and discomfort should be questioned carefully about recent injuries and exposures. Patients may be injured in a number of different situations and suffer an intraocular foreign body (IOFB). Precipitating cir-cumstances can include working in construction, striking metal against metal, being involved in motor vehicle crashes with facial injury, gunshot wounds, and grinding-wheel work.

IOFB is diagnosed and localized by slit-lamp biomicroscopy and indirect ophthalmoscopy, as well as CT or ultrasonography. MRI is contraindicated because most foreign bodies are metallic and magnetic. 

It is important to determine the composition, size, and location of the IOFB and affected eye structures. Every effort should be made to identify the type of IOFB and whether it is magnetic. Iron, steel, copper, and vegetable matter cause intense inflammatory reactions. The incidence of endophthalmitis is also high. If the cornea is perforated, tetanus prophylaxis and intra-venous antibiotics are administered. The extraction route (ie, sur-gical incision) of the foreign body depends on its location and composition and associated ocular injuries. Specially designed IOFB forceps and magnets are used to grasp and remove the for-eign body. Any damaged area of the retina is treated to prevent retinal detachment.