Ocular injuries

The ophthalmic assistant and associated allied personnel in ophthalmology should have knowledge about the prevention of eye accidents and the first-aid therapy of trauma in industry, as well as at home. Reports from the National Society for the Prevention of Blindness reveal that ocular injury is responsible for 5% of all blindness in children of school and preschool age. Many athletic activities, including racquet sports, boxing, and hockey, carry the risk of visual casualties. Industrial eye injuries are virtually a daily occurrence in every ophthalmologist’s office and in every emergency center of a hospital.

The escalation of traumatic eye injuries is partly attributable to the progress achieved in the field of transportation, to the development of potentially dangerous consumer home products and children’s toys, and to advancements in industrial mechanization, without corresponding advances in personal safety devices. Only in large industrial plants have safety programs been inaugurated to detect visual disabilities and to prevent eye accidents. Prevent Blindness America, formerly known as the National Society to Prevent Blindness, launched Wise Owl Club in 1948, an industrial and school eye safety incentive program. The program recognized over 85,000 cases who have had one or both eyes saved from a serious injury by the use of protective lenses. Guidelines for preventing eye injuries are published on their website www.preventblindness.org/preventing-eye-injuries .

Despite rigid precautionary safety measures, however, eye accidents will continue to occur because of carelessness, chance, and the tendency of people to ignore the safety measures provided for them.

This chapter deals with first-aid therapy of eye injuries and preventive measures to help reduce the loss of vision from trauma.

Diagnosis of ocular injury

The diagnosis of an eye injury can be made by a careful history of the injury in relation to the time and type of injury. A history of discomfort and reduction in vision may indicate the severity of injury. Objective signs require careful external examination that includes comparison with the unaffected eye. Pressure should never be exerted in separating the eyelids, but the upper lid should be pushed up against the bone under the eyebrow and the lower lid depressed with pressure only on the bone of the cheek below. All injuries to the globe, until proved otherwise, should be examined as if the globe has been ruptured. If magnification is required, a × 2 loupe or slit-lamp microscope can detect areas of damage not otherwise discovered.

Conjunctival and corneal foreign bodies

Despite the many anatomic and physiologic protective factors around the eye, nearly everyone at one time or another has had a foreign body in the eye. In most instances, the ensuing tearing and blinking of the lids have been sufficient to dislodge the irritant. It is when these natural mechanisms fail to remove a foreign body that one has to have it located and removed ( Figs. 21.1 and 21.2 ).

Fig. 21.1

Metallic foreign body of the superficial cornea with surrounding cellular infiltration.

(From Kanski J, Bowling B. Clinical Ophthalmology—A Systematic Approach . 7th ed. Edinburgh: Saunders; 2011.)

Fig. 21.2

Redness, foreign body sensation, and photophobia occur in the presence of a corneal foreign body.

(From Stein HA, Slatt BJ, Stein RM. A Primer in Ophthalmology: A Textbook for Students . St Louis: Mosby; 1992.)

When a foreign body has lodged in the cornea, examination should always begin by determining the patient’s best-corrected visual acuity of the injured eye with glasses on or with the addition of a pinhole disc if the vision is reduced. In this way, any preexisting visual impairment will not be attributed to the trauma and removal of the foreign body. In taking the history, the examiner should attempt to ascertain the source of the fragment because the type of foreign body will influence the amount of tissue destruction and rate of repair. Particles of copper and brass are notoriously more irritating to the eye than are iron and steel. High-velocity foreign bodies—that is, those catapulted by hammering, chiseling, or lathing—are prone to penetrate the cornea deeply, or even to perforate it, as opposed to the wind-blown particle that embeds itself in the superficial corneal epithelium.

It usually is expedient to place two or three drops of a local anesthetic, such as proparacaine hydrochloride 0.5% (Alcaine) or tetracaine hydrochloride 0.5% (Altacaine), into the lower conjunctival sac to facilitate surface anesthesia. This makes the patient more comfortable and allows the examiner to scrutinize the injured eye with ease. The best instrument for examining the cornea is the slit-lamp microscope because it offers simultaneously high magnification and strong focal illumination. If a foreign body cannot be seen, a strip of fluorescein paper can be placed in the eye to stain the surface of the cornea because foreign bodies become visible when surrounded by the stain. If the foreign body has become dislodged by the patient’s blinking and tearing, the fluorescein will stain the resultant corneal defect. In many cases, the cornea will show many surface scratches and the foreign body will be located on the undersurface of the upper or lower lid. Routinely, an examination of the palpebral conjunctiva lining both the upper and lower lids should be performed. Inspection of the conjunctiva lining the lower lid is carried out simply by depressing the lower lid. The undersurface of the upper lid is examined by everting it. The patient is asked to look down while the eyelashes are grasped and pulled over a glass rod, toothpick, or cotton tip applicator ( Fig. 21.3 ). Alternatively, this examination can be accomplished by everting the upper lid over a transilluminator or muscle light. The foreign body is usually revealed as an opaque speck in the red glow of the lid tissue.

Fig. 21.3

(A) Eversion of the upper eyelid over an applicator. (B) Identification of foreign body on underside of eyelid.

The treatment of corneal foreign bodies is total removal. A superficial foreign body can sometimes be dislodged by a gentle stream of saline solution delivered from an irrigator, or it can be wiped off by moist cotton tip applicator. If these measures fail, a nonpenetrating superficial foreign body can be carefully dislodged using the tip of a 27- or 25-gauge needle or it can be lifted from its base by the use of a sterile jeweler’s forceps. The upper and lower eyelids must be immobilized using a speculum or by gently holding them in place. After 6 to 8 hours, a metallic foreign body may form a brownish-orange rust ring in the corneal tissue. This rust spot can be difficult to remove because it becomes adherent to the surrounding corneal stroma. It can be lifted with a needle, jeweler’s forceps or it can be smoothened out by a corneal spud or burr ( Fig. 21.4 ), under magnification by a slit-lamp microscope ( Fig. 21.5 ). In such cases, it can help to have a corneal burr on hand to remove the rust ring. Small dental drills make excellent corneal burrs. The tenacity of the rust is so great that often the corneal spud will only fragment the rusted spot. The goal is to remove as much of the rust ring as possible without causing too much tissue disruption or corneal perforation.

Fig. 21.4

Rotating burr for removal of rust rings.

Fig. 21.5

Removal of foreign body under magnification of the slit-lamp microscope.

After the removal of a foreign body, the patient is cautioned about the discomfort caused by the epithelial defect from the foreign body and the removal process. Broad-spectrum topical antibiotics are prescribed and the patient is seen the next day. Rarely, in the case of severe discomfort, a bandage contact lens can be used with the precaution that this can promote an infective process; antibiotics and next day follow-up are essential if this is done. A short-acting topical cycloplegic drop can be used to alleviate any pain resulting from iris spasm. A pressure patch can be used cautiously but is not usually necessary. A corneal foreign body should be treated as an ocular emergency. It is desirable, but not mandatory, that the foreign body be removed as soon after the mishap as possible. If there are extenuating circumstances, however, such as the ophthalmologists being involved in surgery, the injured eye should receive some antibiotic drops until the patient is seen. It is imperative, however, to relieve the patient’s symptoms. The discomfort of a corneal foreign body can be intense. Some relief of pain can be obtained with over-the-counter medications, such as acetaminophen (Tylenol) or ibuprofen (Advil). The patient should never be given a local anesthetic ointment or drops to take home because local anesthetics only interfere with wound healing and mask complications.

If the foreign body becomes dislodged by forceful and frequent blinking and the profusion of tears, the patient may still feel that something is in the eye. This is because injury to the cornea, whether it is caused by inflammation, a foreign body, or an abrasion, yields the same symptom: a foreign body sensation.

Conjunctival foreign bodies do not, as a rule, give rise to pain or discomfort in the eye. If they lodge in the bulbar conjunctiva, they usually are easily visible because of the white background of the underlying sclera. Exceptions that are not visible are chips of glass and plastic from a broken contact lens. Superficial conjunctival foreign bodies are removed either by the application of a moistened cotton-tipped applicator or by gentle irrigation with saline solution. Occasionally, forceps may be required if there is blood around the foreign body; the ophthalmic assistant should be aware that penetration of the eye may have occurred.

Corneal abrasions

Corneal abrasions are superficial scratches and erosions of the cornea ( Figs. 21.6 and 21.7 ). They are found after corneal foreign bodies have been removed, either spontaneously or with treatment. They are most commonly found after injuries caused by paper, fingernails, wires, and so forth. A corneal abrasion, unless it is large, cannot be seen with the naked eye. Patients with a corneal abrasion complain of a foreign body sensation of the eye. Often these patients are seen by a nurse or a friend and told that there is nothing in their eye and as a result they suffer until they are finally seen by the ophthalmologist. Any patient who complains of a foreign body sensation of the eye should be seen. Fluorescein strips should be placed in the eye ( Figs. 21.8 and 21.9 ) to stain the area of the corneal defect. Careful assessment of the eye with eversion of eyelids, as mentioned before, is necessary. A dilated fundus examination is essential in the case of a history suggestive of a penetrating foreign body.

Fig. 21.6

(A) Deep corneal erosion. (B) Vertical corneal scratches from foreign body under upper lid.

Fig. 21.7

Corneal abrasion as a result of thermal burn from hair curler.

Fig. 21.8

Corneal abrasion is characterized by ciliary injection and an epithelial defect (which stains with fluorescein).

(From Stein HA, Slatt BJ, Stein RM. A Primer in Ophthalmology: A Textbook for Students . St Louis: Mosby; 1992.)

Fig. 21.9

Application of moistened fluorescein paper strip. Some practitioners find the lower cul-de-sac easier to use.

Most corneal abrasions heal spontaneously. Some ophthalmologists choose to prescribe broad-spectrum topical antibiotics as a prophylactic measure. The larger the abrasion, the more time it takes to heal. Follow-up is usually to ensure no infection has occurred and the cornea has healed well. The same principles mentioned earlier apply with regards to the use of a bandage contact lens.

Aftercare of patients with superficial injuries

The following points summarize the aftercare of a patient with a superficial corneal and conjunctival injury:

  • 1.

    Arrangements should be made to have the patient driven home.

    • The patient should be warned that discomfort in the eye may occur an hour or two after office treatment. This is the length of time that the local anesthetic given in the office usually remains effective. If a feeling of irritation continues, the patient should be instructed to take a pain-relieving drug.

  • 2.

    Medication other than some general analgesics should not be given. The patient also should be told that it is best to return home and rest.

  • 3.

    The rate of healing depends on the area of the tissue injured, the amount of tissue devitalized, the presence or absence of infection, and the nature of the injuring agent.

  • 4.

    The patient should be instructed to return to their follow-up as planned or earlier if there is significant worsening in vision, pain, or discharge.

Intraocular foreign bodies

Intraocular foreign bodies constitute a surgical emergency. Often the site of penetration is not visible externally ( Fig. 21.10 ). The ophthalmic assistant should not make a judgment on the gravity of a foreign body injury on the basis of the eye’s external appearance.

Fig. 21.10

Intraocular foreign bodies can be found in a variety of sites: in the anterior chamber, lens, vitreous, or retina.

(From Stein HA, Slatt BJ, Stein RM. A Primer in Ophthalmology: A Textbook for Students . St Louis: Mosby; 1992.)

Because the severity of the intraocular damage depends on the size, shape, and composition of the foreign body, the assistant should attempt to obtain an accurate description of the nature of the type of metal embedded. Often, it is possible to ascertain the source of the fragment. This is very important because the success of the operative procedure depends to a large extent on whether the fragment is magnetic. The patient should be reassured that everything possible will be done, but should not be promised a full recovery of the eye because eyes injured by foreign bodies, particularly those lodged in the posterior pole (i.e., in the retina or vitreous), often do poorly.

One can serve the patient best by making sure that this type of injury is seen by the attending ophthalmologist immediately. Relatives should be notified and the hospital, particularly the operating room personnel, should be informed of the emergency. Transportation to the hospital should be arranged so that the patient is not kept waiting in the office. A protective shield should be placed over the patient, primarily to prevent from causing further damage to the eye by rubbing it or by cleaning it with a dirty handkerchief.

The ophthalmic assistant should always be aware of the possibility of the presence of an intraocular foreign body. Intraocular foreign bodies usually are high-velocity small missiles and should be suspected in accidents in which striking, grinding, or cutting force is applied to metal. Fast-moving particles may penetrate the eye without producing any pain, discomfort, or gross visible signs and yet still may cause severe damage to the eye. Fig. 21.11 shows an air pellet in the eye that passed through the upper eyelid.

Fig. 21.11

Intraocular foreign body. Air pellet entry into the globe.

Contusion of the eyelids: black eye

A black eye is the result of an injury to the orbital margin or eyelids from a blunt object, such as a fist ( Fig. 21.12 ). The appearance of a black eye is quite alarming to the patient because of the large extravasation of blood underneath the skin. A patient with this type of injury should be seen immediately because examination of the globe is easiest in the period following the injury. After 1 or 2 hours, the lids become so swollen and taut that examination of the underlying eye becomes very difficult. The orbital rim should be palpated to make sure there are no broken chips.

Fig. 21.12

Contusions of the eyelids with ecchymosis.

(From Kanski J. Clinical Ophthalmology . 8th ed. Oxford: Elsevier/Mosby; 2015.)

Treatment of a black eye is the application of cold compresses in the immediate phase to reduce the swelling and further bleeding and use of analgesics to relieve the pain. Usually within 5 to 7 days, the swelling subsides and the hematoma changes in color, gradually fading away as the blood decomposes underneath the skin. Although a black eye is quite innocuous, the secondary contusion to the globe can cause considerable disruption within the eye. The effects of contusion to the globe include traumatic hyphema, dislocated lens, vitreous hemorrhage, and tears in the choroid and retina.

A black eye may also be associated with a broken nose because the bones between the orbit and the nose are extremely thin. Consequently, an abnormal communication (fistula) may arise between the nose and the soft tissues of the lids. When the nose is blown, air may be forced under the pressure into the lids, causing swelling and the development of a curious crackling feeling under the skin. Because there is a risk of spreading infection from the nose into the orbit and eyelids, the patient should be instructed not to blow the nose forcefully.

Frequently, a blow to the lids and globe is sufficiently strong to cause a blow-out fracture of the orbit. The muscles on the inferior surface of the globe (the inferior rectus and inferior oblique muscles) may become incarcerated in the defect in the floor of the orbit and the eye cannot be elevated. Computed tomography (CT) scan of the orbits is required. The majority of blowout fractures do not require surgery and are typically observed for 1 to 2 weeks to allow the swelling to subside before making a decision. In an adult with a blowout fracture, surgical treatment is done if there is persistent diplopia in primary gaze, a large size fracture (>50% of the floor) or if there is enophthalmos of more than 2 mm. Surgery is done by freeing the wedged muscles and placing an implant of bone or plastic over the fracture site. Conversely, a blowout fracture in the pediatric population requires urgent repair as the entrapped inferior recture muscle can become incarcerated beneath a trapdoor fracture. The child can present with a seemingly uninjured appearance, so known as the white-eyed orbital blowout fracture . Eye motility can stimulate the oculocardiac reflex with resultant pain, nausea, and bradycardia.

Contusions of the globe

Contusions of the globe may be caused by an explosive force, such as an air blast, a blow to the bony orbit, or direct injury to the eye itself. Initially, the effects of a blow to the eye can be disastrous because perforation of the globe, with prolapse of the intraocular contents, vitreous hemorrhage, retinal detachment, and rupture of the choroid may occur as an immediate complication. If the hemorrhage is confined to the anterior chamber, it is called a hyphema. If the hemorrhage fills the entire anterior chamber, it is called a total hyphema. If the blood is dark red-black, it is sometimes called an eight-ball or black-ball hyphema. In the event that the initial injury to the eye appears to be minimal, loss of vision can result from complications occurring later, for example, glaucoma, cataract, and sympathetic ophthalmia.

Sometimes the retina may be affected. Any shadow, floaters, or loss of vision should be investigated because tears in the retina, retinal detachment, or vitreous hemorrhage may have occurred ( Figs. 21.13–21.15 ).

Fig. 21.13

Large retinal tear with associated retinal detach-ment.

(From Kanski J, Bowling B. Clinical Ophthalmology—A Systematic Approach . 7th ed. Edinburgh: Saunders; 2011.)

Fig. 21.14

In retinal detachment, the retina appears white when elevated. If the macula is detached, the central vision will be diminished.

(Modified from Stein R, Stein H, eds. Management of Ocular Emergencies . 5th ed. Montreal: Mediconcept; 2010.)

Fig. 21.15

A vitreous hemorrhage that obscures visibility of the fundus.

(Modified from Stein R, Stein H, eds. Management of Ocular Emergencies . 5th ed. Montreal: Mediconcept; 2010.)

Early complications

Early complications of contusion injuries include subconjunctival hemorrhage, hyphema (hemorrhage into the anterior chamber; Fig. 21.16 ), iris involvement (iridodialysis, i.e., separation of the iris at its base), tears of the sphincter muscle and iritis, glaucoma secondary to iritis or hyphema, dislocation of the lens, vitreous hemorrhage, retinal tears, detachment and hemorrhage, choroidal rupture, scleral rupture, and avulsion of the optic nerve.

Jun 26, 2022 | Posted by in OPHTHALMOLOGY | Comments Off on Ocular injuries
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