AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Corneal abrasion is probably the most common eye injury and perhaps one of the most neglected. It occurs because of a disruption in the integrity of the corneal epithelium or because the corneal surface scraped away or denuded as a result of physical external forces. Corneal epithelial abrasions can be small or large, but they usually heal without serious sequelae. However, deep corneal involvement may result in facet formation in the epithelium or scar formation in the stroma.

Abrasions of the corneal epithelium are common and frequently missed. Because they heal rapidly, they are considered of little consequence. Corneal abrasions occur in any situation that causes epithelial compromise. Examples include corneal or epithelial disease (eg, dry eye), superficial corneal injury or ocular injuries (eg, those due to foreign bodies), and contact lens wear (eg, daily disposable soft lenses, extended-wear soft lenses, gas permeable lenses, hard polymethylmethacrylate lenses). Spontaneous corneal abrasions may be associated with map-dot-fingerprint dystrophy or recurrent corneal erosion syndrome.

Corneal abrasions can be classified as traumatic, foreign body related, contact lens related, or spontaneous. Spontaneous corneal abrasions are also known as recurrent erosions.

Pathophysiology

Anatomy and physiology of corneal abrasion

Abrasion is a defect in the surface of the cornea that is limited to the epithelial layers and that does not penetrate the Bowman membrane. In some cases, the bulbar conjunctiva is also involved. Corneal abrasion results from physical or chemical trauma. Severe corneal injuries can also involve the deeper, thicker stromal layer; in this situation, the term corneal ulcer may be used.

The conjunctival response to corneal wounding has been known since Mann first observed that peripheral corneal abrasions heal by the sliding of limbal cells to cover the epithelial defect.¹ This response is split into 2 phases: (1) the response of the limbal epithelium, which is the source of the corneal epithelial stem cells, and (2) the response of the conjunctival epithelium itself.

Under normal circumstances, the limbal epithelium acts as a barrier and exerts an inhibitory growth pressure that prevents the migration of conjunctival epithelial cells onto the cornea. Like the rest of the surface of the body, the conjunctiva and the cornea are in a constant state of turnover. Corneal epithelial cells are continuously shed into the tear pool, and they are simultaneously replenished by cells moving centrally from the limbus and anteriorly from the basal layer of the epithelium. Movement from the basal to superficial layers is relatively rapid, requiring 7-10 days; however, movement from the limbus to the center of the cornea is slow and may require months.

This normal physiologic process is exaggerated in the case of a corneal abrasion. During corneal healing of a lesion, corneal epithelial cells become flattened, they spread, and they move across the defect until they cover it completely. Cell proliferation, which is independent of cell migration, begins approximately 24 hours after injury. Stem cells from the limbus also respond by proliferating to give rise to daughter cells called transient amplifying cells. These cells migrate to heal the corneal defect and proliferate to replenish the wounded area.

The observation of limbal pigment migrating onto the clear cornea provided additional evidence of this process. The concept that the limbal cells form a barrier to conjunctival cells was supported further by the observation that rabbit eyes treated for 120 seconds with N-heptanal, which removed the corneal and conjunctival epithelium but left the limbal basal cells intact, healed with the corneal epithelium and had unvascularized corneas. However, when the entire limbal zone was surgically removed along with N-heptanal treatment, corneal vascularization and conjunctivalization was observed.

Demonstration of the centripetal migration of limbal cells (marked by India ink) provided more direct evidence of this concept. These cells migrate in masses as a continuous, coherent sheet, with most cells retaining their positions relative to each other, much like the movement of a herd of cattle.

Rearrangement of intracellular actin filaments plays a role in movement. Cell migration can be inhibited by blocking polymerization of actin, indicating that actin filaments actively participate in the mechanism of cell motion. Some authors believe that conjunctival and limbal epithelial cells may contribute to the regeneration of corneal epithelium. Marked proliferative responses in the conjunctiva after a central corneal epithelium abrasion have been described.

Why the conjunctival epithelium should proliferate in response to a central corneal wound is unknown. One possibility is that the proliferation replenishes the number of goblet cells, which decreases by up to 50% after corneal wounding. However, proliferation occurs at high levels in the bulbar conjunctiva, which contains few if any goblet cells. The apparent decrease in cell number is more likely the result of mucin secretion rather than actual loss of goblet cells. Alternately, conjunctival cells may migrate into the limbus or cornea to help replenish the wound area. No firm data suggest that conjunctival epithelium migrates onto the corneal surface in the presence of intact limbal epithelium. Last, healing of the corneal epithelial wound is not complete until the newly regenerated epithelium has firmly anchored itself to the underlying connective tissue.

Permanent anchoring units are not formed until the wound defect is covered completely. Epithelial cells migrate rapidly and develop strong, permanent adhesions within 1 week when the basement membrane is regularly formed and released during the cell migration process.

Although transient attachments are regularly formed and released during the cell migration process, formation of normal adhesions takes 6 weeks, according to Dua et al.² Tiny buds of corneal epithelium are present along the contact line between the normal corneal epithelium and the migrating conjunctival epithelium. These buds arise from the corneal epithelium, and normal corneal epithelium appears to replace the conjunctival epithelium by gradually pushing it toward the limbus. The magnitude and extent of both the conjunctival and corneal regenerative responses to a corneal abrasion are correlated with the size of the wound. Large erosions were reported to induce a pronounced response in the rate of epithelial cell migration and mitosis at the limbus.

Insults caused by chemical injuries, Stevens-Johnson syndrome, contact lens–induced keratopathy, and aniridia result in limbal damage. These insults cause delayed healing of the cornea, recurrent epithelial erosions, corneal vascularizations, and conjunctival epithelial ingrowth.

Role of the epithelial defect

A long-standing clinical observation is that corneal abrasions and bacterial corneal infections do not occur in patients with an intact, healthy epithelium. Bacterial keratitis and abrasions develop in 1 of 3 types of patients: (1) those with trauma to the cornea; (2) those with epithelial defects due to intrinsic disease (eg, dry eye, exposure keratitis, neurotrophic keratitis, postinfectious persistent epithelial defects); and (3) those who wear contact lenses, especially extended-wear hydrophilic lenses.

The common feature among the 3 groups is a defect in the corneal epithelium to which the bacteria must adhere to start the infection. Mechanisms underlying the development of epithelial defects in the first 2 groups are self-evident. In the third group, contact lenses may lead to epithelial injury in different ways. The cornea can be injured by insertion or removal of the lens, by trauma from defects in or deposits on the lens, by lens-induced hypoxia, or by chemical toxicity from contact-lens disinfectants.

Defects in the epithelium need not be full thickness. Overnight wearing of soft lenses, which do provide inadequate oxygen transmissibility to prevent hypoxia, causes superficial desquamation of epithelium and increases the propensity for abrasions. Corneal swelling induced by overnight wearing of contact lenses is the most important factor. The cornea normally swells 2-4% during sleep. With a contact lens, overnight swelling is increased to an average of 15%, and gross stromal edema can be present on awakening. In some patients, induced corneal swelling can be sufficient to cause bullae; these can rupture, leading to epithelial defects.

Frequency

United States

Corneal abrasions are the most common eye injuries and especially prevalent among people who wear contact lenses. Although corneal abrasions account for about 10% of eye-related emergency visits, the estimated incidence varies by population and depends on how they are defined and the activities involved in the mechanism of injury.

A sampling of diagnoses in the offices of family practice clinicians, internists, and pediatricians in the United States in 1985 found that eye complaints constituted 2% of all patient visits; traumatic conditions and foreign bodies were the reason for 8% of these visits.

Workplace eye injuries cause significant yet avoidable (with protective eyewear) morbidity and lost productivity. A study of eye injuries in a major US automotive corporation found an annual incidence of 15 eye injuries per 1000 employees. The eye injuries comprised 6% of total injuries, and corneal foreign bodies and abrasions were 87% of eye injuries. One third of eye injuries resulted in the inability of workers to resume normal duties for at least 1 day. In another report, most patients with corneal foreign bodies did not take more than 1 day off work, and up to 30% sought treatment outside of working hours to avoid lost time from work. See also the Mortality/Morbidity section. 

International

The incidence of nonpenetrating injuries to the eye, which includes corneal abrasions, is 1.57% per year.

Corneal abrasions are common, accounting for 12-13% of new cases seen in 2 different eye emergency units in the United Kingdom in 1981 and in 1995. They are also frequent presenting problems in general hospital emergency departments. In 1983, at a general hospital emergency department in the United Kingdom, 6% of all new cases were eye cases. Trauma accounted for 66% of these cases, or 4% of all cases; corneal abrasions or corneal or conjunctival foreign bodies accounted for 80% of eye trauma cases, or 3% of all cases.

Mortality/Morbidity

Although corneal abrasions are often regarded as inconsequential (especially by patients who are poor), these injuries can cause significant ocular and visual morbidity.

• Minor injuries (eg, superficial foreign body injuries, corneal abrasions) can lead to blindness; the degree depends on the circumstances of the injury and the treatment received. Information about minor injuries is not available from hospital-based data, and population-based interviews are usually required to obtain data regarding treated and untreated eye injuries.
• Minor injuries may place substantial economic burdens on otherwise healthy people because of time lost from work or school. Foreign body sensation and pain can result in loss of productivity. These abrasions usually heal with time, but in people who are poorly nourished or who have compromised corneas, this problem can be devastating.
• Close follow-up care is necessary because of the ever-present danger of the abrasion progressing to an ulcer. Essentially all corneal ulcers begin with an abrasion. Abrasions involving exposure to vegetable matter are at a high risk for becoming fungal ulcers. Abrasions resulting from contact lens wear should be watched for pseudomonal and amebic keratitis.
• Significant morbidity is uncommon and mostly observed with infectious complications or allergies to medications used for treatment. Recurrent erosions are common complications of abrasions, particularly in patients with dystrophy of the epithelial basement membrane.

Race

Rates of corneal abrasion are equal in all races.

Sex

More males than females are treated for corneal abrasions.

Age

The incidence is increased among those of working age because younger people are more active than older people; however, people of all ages can have a corneal abrasion.

CLINICAL

Section 3 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

The patient's history typically includes trauma to the eye due to either a foreign object or a contact lens.

In general, symptoms of a corneal abrasion include foreign body sensation, pain, and photophobia. Symptoms range from mild foreign body sensation in cases of small abrasions to severe pain in large abrasions. Symptoms typically begin instantly after trauma occurs and can last minutes to days depending on the size of the abrasion. Other symptoms include photophobia, especially if secondary traumatic iritis is present. Excessive tearing may occur. Conjunctival injection and eyelid swelling may be present.

• Patients with concomitant ocular injury, such as a traumatic iritis, can usually clearly distinguish between the aching discomfort ciliary spasm causes and the foreign body sensation or scratchy discomfort superficial corneal injury causes.
• Some patients have recurrent corneal abrasions days to years after the original abrasion heals. This is called recurrent corneal erosion syndrome. 
• • Symptoms include foreign body sensation, pain, and photophobia.
  • Sharp, severe pain; photophobia; and lacrimation most commonly occur when the eyelids are opened during or immediately after awakening from sleep.
  • Clinical signs are those of a corneal abrasion, but they may be minimal, especially if the patient is examined several hours after the onset of pain.
• In patients with recurrent erosions, areas of erosion are occasionally slow to heal, but the primary concern is their recurrent nature.  
• • Therapeutic efforts have included micropunctures of the Bowman membrane to expose the regenerating epithelial basement membrane to type I collagen in the corneal stroma.
  • Other treatment options to prevent erosions from recurring include diamond-bur polishing of the Bowman membrane and excimer laser phototherapeutic keratectomy (PTK).
• Unconscious patients are prone to iatrogenic corneal abrasions, as their eye remains open for some time and becomes dry; the nursing staff may inadvertently rub it while giving a face bath, abrading the cornea with a napkin or towel.
• Toxic chemicals (eg, ear drops) accidentally instilled into the eye can cause corneal abrasions.
• The author saw a patient with multiple abrasions on the cornea. While pruning a cactus plant, white, milky fluid from the cactus splashed into the patient’s eye and caused corneal abrasions, resulting in extreme discomfort for several days.

Physical

In some cases, the findings are missed because of the insignificant nature of the causative agent or because of insignificant discomfort; however, the majority of patients with corneal abrasions have the same clinical presentation. The corneal epithelium is richly innervated with sensory pain fibers from the trigeminal nerve. Thus, patients typically complain of excruciating eye pain and an inability to open the eye due to foreign body sensation. Often, patients are too uncomfortable to work, drive, or read, and the pain frequently precludes sleep. Multiple attempts by the patient to "wash out" the eye can further disrupt the epithelial surface.

• In cases of a significant abrasion, a slit lamp examination reveals a defect in the corneal epithelium. This defect can be confirmed by placing a drop of fluorescein in the inferior fornix. The fluorescein flows into the defect and appears to glow under the blue cobalt light of the slit lamp. Examination with a Wood light reveals fluorescein uptake whenever corneal epithelial cells are damaged or lost.
• Bulbar conjunctival injection is present.
• The patient's clinical presentation is usually unilateral when the corneal abrasion is associated with trauma or bilateral when it is associated with heritable or dystrophic disease.
• Most patients present with the following:  
• • Photophobia
  • Watering
  • Foreign body sensation
  • Gritty feeling
  • Pain
  • Circumcorneal injection
• In advanced cases, findings can be more drastic:  
• • Corneal edema
  • Bacterial corneal ulcers
  • Fungal, amebic, or viral corneal ulcers
  • Uveitis
• In advanced cases, the following findings are possible:  
• • Recurrent corneal erosions
  • Filamentary keratitis
  • Corneal abscess
  • Corneal perforation

Causes

• Contact lens trauma: Contact lens–induced epithelial defects or direct trauma during lens insertion or removal can cause corneal abrasions.
• • Abrasions occur more frequently with rigid lenses than with other lenses, possibly because of their small diameter and the sharp corneal defects they cause. Corneal abrasions due to soft lenses are observed most frequently with tight or extended-wear lenses. In these situations, acute epithelial hypoxia impairs attachment of the epithelium to the Bowman membrane. Treatment is the same as that for abrasions not related to contact lenses, except that patching is not used in this situation.
  • Careful examination of the contact lens and its fit is important to identify potential causes of recurrent abrasions. The patient should also be asked about his or her techniques of lens removal.
  • The most common trauma is an inferior abrasion of the cornea caused by lens removal. Sometimes, the person's fingernail slices the contact lens and also the cornea. More often, the lens becomes slightly dehydrated at the end of the day because of a lack of blinking. The lens adheres to the cornea, removing the epithelium. This area may not heal well, especially if the epithelial cells are continually torn away. After the contact lens is removed, the patient may feel discomfort; however, no pain occurs when the lens is worn because it acts as a bandage. Patients who incompletely blink and those who work in a dry environment, read most of the day, or look at TV or computer screens should be warned about this complication.
  • A foreign body may become trapped under a contact lens and produce linear scratch marks on the cornea. The total irregularity of these wavy abrasions is the clue to this cause of injury.
  • A soft lens offers no protection against blunt trauma to the eye, but it does not pose any additional jeopardy in terms of eye trauma. For example, a soft lens does not adversely affect an eye injured by a fist or a ball. In industrial settings, a soft lens is not a substitute for safety glasses.
  • Rigid contact lenses may break or chip, causing punctate epithelial keratopathy.
  • Adverse corneal events, such as corneal abrasions, have been reported with techniques of overnight corneal reshaping with orthokeratology. Lang concluded that corneal compromise and poor compliance can cause adverse events with corneal reshaping.³ The need for ongoing patient education is important in both children and adults who wear contact lenses.
• Sports-related injury: Corneal abrasions can occur in almost all sports. They most frequently occur in young people who participate in various sports.  
• • Soccer: In places where soccer is played frequently, impact with the soccer ball causes approximately one third of all sports-related eye injuries. Contrary to previous ophthalmologic teaching that balls larger than 4 inches in diameter rarely cause eye injury, 8.6-inch soccer balls cause most soccer-related eye injuries, both serious (eg, hyphema, vitreous hemorrhage, retinal tear, chorioretinal rupture, angle recession) and minor (eg, corneal abrasions, contusions).
  • Basketball: Approximately 1 in 10 college basketball players has an eye injury each year. Most basketball-related eye injuries are corneal abrasions caused by an opponent's fingers or elbows striking the player's eye.
  • Wrestling: The incidence of severe eye injuries in wrestling is low. In a study at Michigan State University, 18.4% of wrestlers had eye injuries that were relatively mild (eg, lacerated eyebrows, corneal abrasions) and that left no permanent damage. The average college team with 25 players and 2600 athlete exposures should expect 1-2 eye injuries each season, with a significant injury every 9-10 seasons.
  • Equestrian events: Although significant eye injuries are not a major risk in equestrian events other than polo, cross-country riders frequently have corneal abrasions from hitting tree branches overhanging the trail. Wearing spectacles with polycarbonate lenses offer adequate protection from this risk.
  • Skiing: Although cross-country skiing causes fewer musculoskeletal injuries than alpine skiing, cross-country skiers are more likely than alpine skiers to have eye injuries, especially corneal abrasions from contact with tree twigs. Both cross-country and downhill skiers can have solar keratopathy (snow blindness) and injuries due to accidents with ski poles.
• Trachoma: The constant corneal abrasion by lashes and inadequate tears can produce corneal erosions, ulceration, and scarring, which constitute the major pathway to blindness in trachoma.
• Lid surgery: Corneal abrasion can result from sutures inadvertently placed through the tarsus or conjunctival surface. After sutures are placed, the lid should be everted to check that they are not exposed. The globe and cornea should be protected during dissection and suture placement. A contact lens corneal protector or lid plate can be used.
• Anesthesia: General anesthesia is more likely to cause adverse systemic effects than local or ocular complications. Ocular problems that do occur are usually not serious and include corneal abrasion, chemical keratitis, hemorrhagic retinopathy, and retinal ischemia (rare).
• • The incidence of corneal abrasion from general anesthesia is as high as 44%.
  • Simple precautions, such as instilling a bland ointment or taping the lids of the inoperative eye closed, may prevent surface trauma produced by the surgical drape, anesthetic mask, or exposure. Decreased tear production under general anesthesia, proptosis, and a poor Bell phenomenon may worsen corneal exposure, requiring eyelid suturing in some susceptible patients.
• Argon laser trabeculoplasty: Complications of argon laser trabeculoplasty include discomfort, acutely elevated intraocular pressure (IOP), progressive visual field loss, peripheral anterior synechiae, iritis, sector palsy of the pupillary sphincter, corneal abrasion, corneal edema, endothelial damage, and vasovagal reaction.
• Tonometry: The plunger can cause corneal abrasion if the eye or tonometer moves during measurement.  
• • In addition, if the disinfectant solution (eg, alcohol) is not removed from the plunger, it can cause a local chemical keratitis where it touches the cornea.
  • The Schiötz tonometer must be used in the supine position or in the sitting position with the head back far enough to be horizontal. An initial blink or avoidance reaction may occur as the patient sees the tonometer descending toward the eye.
• Other causes include the following:  
• • Eyelid margin injuries and avulsions
  • Punctal and canalicular lacerations
  • Injury due to fingers, fingernails, paper, eye makeup brushes, self-inflicted rubbing, or exposure to toxic sprays
  • Blowing dust, sand, or debris
  • Iatrogenic factors - Unconsciousness, accidental injury by health care workers, improper eyelid patching in patients with Bell palsy, and other neuropathies in which the eyelid cannot be closed voluntarily
  • Corneal foreign bodies that are difficult to see (eg, small glass fragments)
  • UV keratitis - History of exposure to electric arc welding or tanning beds without proper eye protection, history of prolonged exposure to bright sunlight without sunglasses (eg, snow blindness)

DIFFERENTIALS

Section 4 of 11  

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• Clinical
• Differentials
• Workup
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• Follow-up
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Other Problems to be Considered

Dendritic keratopathy: Corneal epithelial changes characterized by a branching pattern are referred to as dendriform or dendritic keratopathy. The foremost entity with a branching pattern is herpes simplex dendritic keratitis. Few other conditions create this pattern, but they should be considered in the differential diagnosis of healing epithelial abrasions. These conditions include dendritic plaques in herpes zoster ophthalmicus and the rare condition of dendriform keratopathy in tyrosinemia. In addition to creating complex dendritic and vortex patterns, healing corneal abrasions may have a simple linear pattern at the forefront of epithelial migration. Such lines are easy to diagnose on the basis of the history and their rapid evolution.

Conjunctiva and cornea: Diabetes affects the cornea by interfering with the hemidesmosomes that anchor the epithelium to its basement membrane. The number of hemidesmosomes in people with diabetes is markedly reduced, a phenomenon that may be due to altered extracellular matrix. As a consequence of this reduction, the epithelium is removed relatively easily, and minimal trauma can lead to corneal abrasions. Moreover, reepithelialization takes longer in people with diabetes than in those without diabetes, and these patients may develop recurrent erosion syndrome. This is a particular problem in patients undergoing vitrectomy because the entire epithelium may be removed at surgery for visualization, delaying healing.

Related conditions include a painful eye and tearing.

WORKUP

Section 5 of 11  

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• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• If a corneal ulcer is suspected, consider ordering bacterial cultures before instilling antibiotics.

Procedures

• Slit lamp examination  
• • Use of a topical anesthetic (eg, proparacaine, tetracaine) may facilitate the examination.
  • In cases of severe photophobia that causes blepharospasm, instillation of a cycloplegic agent (eg, Cyclogyl, homatropine) 20-30 minutes before the examination may be required.
  • Perform fluorescein instillation and examination with blue light. (Fluorescein can permanently stain soft contact lenses. Do not forget to remove such lenses before applying the stain.)
  • Examine the anterior chamber for evidence of iritis (cells and flare).
• Evert the eyelid to look for blepharoconjunctival foreign bodies.

Histologic Findings

On histopathologic examination, intercellular and intracellular epithelial edema is associated with intraepithelial cysts, cellular debris, and intermittent pyknotic nuclei. Intraepithelial basement membrane formation may be present. Basement membrane under regenerating epithelium may appear thickened and multilaminar. Hemidesmosomes tend to be absent or form late in the course of epithelial healing.

Corneal abrasion and inflammation, paracentesis, intraocular infection, and uveal inflammation all cause a breakdown of the blood-aqueous barrier so that plasma proteins and inflammatory cells pour into the anterior chamber. As a result, inflamed aqueous humor has increased levels of serum proteins, including immunoglobulins and complement components C1-C7.

TREATMENT

Section 6 of 11  

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Medical Care

• Although use of prophylactic antibiotics after trauma or surgery is sometimes discouraged in general medicine, ophthalmologists appear justified in prescribing a topical antibiotic for even minor corneal abrasions to prevent bacterial infection or a corneal ulcer.  
• • De-epithelialized cornea is more susceptible than intact cornea to infection, especially if the eye is patched. The injured cornea is vulnerable not only to pathogens contaminating any foreign body that produced the abrasion but also to potential pathogens present in the normal conjunctival flora.
  • The use of prophylactic periocular injections or systemic administration of antibiotics after corneal abrasions is controversial. Although systemic antibiotics may not be given prophylactically, local antibiotic drops are often administered in cases of corneal abrasions.
• Small abrasions can be managed on an outpatient basis. Ice compresses should be used for 24-48 hours to reduce postoperative edema. Warm compresses can be used thereafter.
• • Inform patients about the signs of wound infection, including increasing pain, erythema, edema, and purulent discharge. This helps in making the decision for early antibiotic intervention.
  • Patients must be informed about the signs and symptoms, such as foreign body sensation, conjunctival injection, and decreased vision, so that complications can be treated promptly.
• Corneal abrasions heal with time.
• • The pain may be severe and should be treated with nonsteroidal anti-inflammatory drops and, if necessary, a soft bandage contact lens. Narcotic analgesia is occasionally required on a short-term basis. Prophylactic antibiotics may be prescribed.
  • Patching the eye may or may not be performed; however, patching should not be performed in patients at high risk of infection, such as those who wear contact lenses and those with trauma caused by vegetable matter.
• Close follow-up care of corneal abrasions is necessary because of the ever-present danger of the abrasion progressing to an ulcer. Essentially all corneal ulcers begin with an abrasion.
• • Abrasions resulting from vegetable matter are at high risk for fungal ulcers. Abrasions resulting from contact lens wear should be monitored for Pseudomonas infection and amebic keratitis.
  • Patients with abrasions should receive follow-up care until healing is complete and no staining with fluorescein occurs.
• Traditionally, noninfected corneal abrasions not related to contact lenses are treated with a topical antibiotic for infection prophylaxis. Sometimes, they are treated with a topical cycloplegic for patient comfort and with a pressure patch. Patching may relieve some of the pain associated with corneal abrasion. The benefit of pressure patching is questionable.  
• • To the authors' knowledge, no randomized double-blind placebo-controlled trials have been conducted to evaluate the advantage of prophylactic antibiotics for noninfected corneal abrasions. Because the incidence of microbial keratitis in this setting is low, such a study is unlikely.
  • Topical fluoroquinolones are used widely and probably the most common prophylactic agents in corneal abrasions. Ofloxacin has been shown to be effective for treating external ocular infection. Other broad-spectrum antibiotics, such as ciprofloxacin drops or ointment, polymyxin/trimethoprim drops, erythromycin ointment, bacitracin ointment, and bacitracin/polymyxin ointment, may also be used.
  • The estimated annual incidence of ulcerative keratitis is 0.13-0.21% for people who wear extended-wear soft contact lenses and 0.02-0.04% for those using daily-wear soft contact lenses. Pseudomonas organisms are the most common causes of infection in patients who wear these lenses.
  • Patching for corneal abrasions in patients who wear contact lenses is not recommended because of potential incubation of infecting organisms and promoting subsequent infectious keratitis.
• Although the use of slowly dissolving lenses made of porcine collagen is an excellent concept, this treatment is not widely used. A therapeutic lens that dissolves after 1-3 days is appealing, but most clinical indications require use of the lens for more than 3 days. An exception might be an uncomplicated corneal abrasion in which a collagen lens could be an alternative to a pressure dressing.
• • One study showed that, with common corneal abrasions, collagen lenses resulted in unexpected discomfort rather than decreased symptoms. In most applications, collagen lenses have failed to find acceptance because of their expense, induced discomfort, difficulty in handling, and lack of optical clarity. Furthermore, the lenses must be constantly replaced in applications in which more than 3 days of wear is required.
  • Another study demonstrated that collagen lenses were not helpful in healing persistent epithelial defects after penetrating keratoplasty.
• Emergency department care
• • Apply topical anesthetic and/or cycloplegic to increase the patient's comfort and to facilitate examination.
  • In 1998, Flynn et al conducted meta-analysis of several studies of patching for corneal abrasions.⁴ Six groups had evaluated pain; 4 found no difference, whereas 2 favored not patching. Complication rates did not differ between use and no use of patches. Flynn et al noted: "Eye patching was not found to improve healing rates or reduce pain in patients with corneal abrasions. Given the theoretical harm of loss of binocular vision and possible increased pain, the route of harmless nonintervention in treating corneal abrasions is recommended."⁴

MEDICATION

Section 7 of 11  

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• Differentials
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• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

The goals of pharmacotherapy are to eradicate the infection, to reduce morbidity, and to prevent complications.

Antibiotics

Routine use of topical antibiotics for corneal abrasions remains controversial. Many emergency physicians have stopped using these agents for minor injuries, though others still treat corneal abrasions with broad-spectrum antibiotic ointments for lubrication and infection prophylaxis. Antibiotic use persists despite its unproved effectiveness and despite evidence that ointments may retard corneal epithelial healing.

Fluoroquinolones have gained popularity in ocular therapy because of their effectiveness in the treatment of bacterial corneal ulcers. Fluoroquinolones are probably the most common agents used for prophylaxis with corneal abrasions because of their broad-spectrum coverage and low toxicity and because of the low resistance of commonly acquired organisms to these drugs. Prolonged and low-frequency dosing should be avoided to discourage the emergence of resistant organisms due to subinhibitory antibiotic concentrations on the ocular surface.

Ofloxacin has effectiveness similar to that of tobramycin for external ocular infection, fortified cefazolin and tobramycin for bacterial keratitis, and fortified gentamicin and cefuroxime for microbial keratitis. Trimethoprim also provides good broad-spectrum coverage and is an excellent prophylactic agent. A combination drop of polymyxin and trimethoprim is commercially available.

Antibiotic ointments (eg, bacitracin, polymyxin/bacitracin, erythromycin, ciprofloxacin) can also be used, especially in children whose crying washes out the drops. For topical use, the sterile powder is reconstituted by adding 20-50 mL sterile water for injection or 0.9% sodium chloride solution for injection to a vial containing polymyxin 500,000 U. This mixture creates a solution with a polymyxin concentration of approximately 10,000-25,000 U/mL (10,000 U = 1 mg).

For large or dirty abrasions, many practitioners prescribe broad-spectrum antibiotic drops, such as trimethoprim/polymyxin B (Polytrim) or sulfacetamide sodium (Sulamyd, Bleph-10), which are inexpensive and least likely to cause complications. Alternatives are an aminoglycoside or a fluoroquinolone.

Abrasions due to contact lenses warrant antibiotic treatment because of their propensity to become infected corneal ulcers. Coverage for gram-negative organisms (especially Pseudomonas species) with agents such as gentamicin (Garamycin), tobramycin (Tobrex), norfloxacin (Chibroxin), or ciprofloxacin (Ciloxan) is recommended.

Avoid antibiotics containing neomycin (eg, Neosporin) because of the high incidence of allergy to neomycin in the general population.

Antibiotic drops are more comfortable than ointments but must be administered every 2-3 hours. Ointments, which retain their antibacterial effect longer than drops, can be used less often (every 4-6 h), but they are more uncomfortable because they can cause visual blurring.

Anticholinergic agents

Instillation of a long-acting cycloplegic agent can provide significant relief for patients with marked photophobia and blepharospasm. These agents relax any ciliary muscle spasm that may cause a deep, aching pain and photophobia. Cycloplegic agents are mydriatics; therefore, to prevent an episode of acute angle closure, ensure that the patient does not have narrow-angle glaucoma.

Drug Category: Antibiotics

Therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Drug Category: Anticholinergic agents - (Cycloplegics and mydriatics)

These drugs are used in large abrasions. Specific agents such as cyclopentolate or atropine or even homatropine drops or ointments are useful adjuncts.

Drug Category: Topical anesthetics

Topical anesthetics are used for analgesia to facilitate an adequate examination. These agents should never be prescribed for home use because they can cause secondary keratitis, compromise healing of the epithelial wound, and block protective corneal reflexes and sensation.

Drug Category: Analgesics

Some ophthalmologists are advocating the use of diclofenac (Voltaren) or ketorolac (Acular) drops with a disposable soft contact lens in addition to antibiotic drops. This therapy may be an effective alternative to patching, as it allows the patient to maintain binocular vision during treatment and reduces inflammation. Patients with all but the most minor abrasions usually require a strong oral narcotic analgesic.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Further Outpatient Care

• Patients with any corneal abrasions should receive follow-up care, especially until the fluorescein stain is negative, to determine if a corneal ulcer has developed.
• Minor abrasions should heal within 24-48 hours and do not require follow-up if the patient is completely asymptomatic at 48 hours. Reexamine large abrasions frequently until reepithelialization occurs and the potential for infection no longer exists.
• Advise eye rest (ie, no reading or work that requires substantial eye movement that might interfere with reepithelialization).
• Advise patients to avoid light or to wear sunglasses for comfort if they have notable photophobia.

In/Out Patient Meds

• Antibiotics should be continued until the patient is asymptomatic.
• Narcotic analgesics (eg, oxycodone, hydrocodone) are often needed to treat severe pain until it can be managed with over-the-counter analgesics.
• Twice-daily cycloplegics may be required to treat large abrasions until their healing is nearly complete.

Deterrence/Prevention

• People must be educated to protect their eyes during activities and work, especially if they are at jobs that increase the risk of corneal abrasion or UV exposure or when hiking through areas of tall foliage (as during farming), for example.
• If patients are unconscious or if they cannot voluntarily close their eyelids (eg, because of Bell palsy or other neuropathies), tape their eyelids closed.

Complications

• If left untreated, corneal abrasions can lead to blinding corneal ulcers.
• Because of shearing injury (eg, due to a fingernail or mascara brush), recurrent epithelial erosion sometimes occurs days to weeks after an abrasion heals.
• • These erosions may be caused by damage to the basement membrane (to which the newly healed overlying cells do not adhere well) and subsequent sloughing due to mild hypoxia that occurs during sleep.
  • Patients are typically awakened in the early morning by the same symptoms as those of a corneal abrasion.
  • Ophthalmologic follow-up care and observation are indicated.
• Corneal ulcerations due to infection are more common after contact lens–related abrasions than after those due to other causes.
• Ocular tetanus is rare.
• Allergic conjunctivitis may occur secondary to ocular medications, particularly neomycin.
• Use of mydriatics in patients with glaucoma may precipitate acute narrow-angle glaucoma.

Prognosis

• The prognosis is usually good, with full recovery of vision if treatment is prompt; however, if a corneal abrasion is left untreated, the outcome can be devastating.
• Some deep abrasions (eg, those involving the corneal stromal layer) in the central visual axis (ie, the central area of the cornea directly over the pupil) heal, but they leave a scar. In these instances, visual acuity may be permanently lost.
• Healing of minor abrasions is expected within 24-48 hours. Extensive or deep abrasions may require a week to heal.

Patient Education

• Although most abrasions do not cause damage, they can lead to blinding corneal infections if they are not treated promptly.
• For excellent patient education resources, visit eMedicine's Eye and Vision Center. Also, see eMedicine's patient education articles Corneal Abrasion; Foreign Body, Eye; and Eye Injuries.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Failure to diagnose the corneal abrasion, failure to treat it adequately, failure to monitor the patient until the abrasion is healed, and failure to diagnose potentially devastating sequelae (eg, corneal ulcers) are pitfalls.
• Strongly consider use of a slit lamp and fluorescein to diagnose a corneal abrasion in ambulatory patients; without the magnification of the slit lamp, small abrasions can be missed.
• In patients with nonhealing abrasions, abuse of topical anesthetics must be considered.
• Failure to consider the possibility of an intraocular foreign body or an ocular perforation, as warranted by the patient's history (eg, use of a string trimmer, metal-on-metal hammering), is a pitfall.
• Failure to identify corneal ulceration and to treat it with appropriate antibiotics is a pitfall.
• Use of mydriatics in patients with known glaucoma or failure to obtain the pertinent history is a pitfall.

Special Concerns

• Patient with corneal abrasions that do not resolve with the use of routine prophylactic antibiotics must be evaluated for conditions that impede healing; examples are infection, neurotrophic keratopathy, and topical anesthetic abuse.

MULTIMEDIA

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  This corneal abrasion appears as a yellow-green area when stained with fluorescein and viewed with a blue light.
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Media type:  Photo

Media file 2:  Corneal abrasion.
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Media type:  Photo

Media file 3:  Corneal abrasion.
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Media type:  Photo

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous