Corneal Injury

Presented byAtul Lawrence

M.Sc Nursing 1st yearRPCON

AnatomyThe cornea is a transparent cover over

the anterior part of the eye that serves several purposes: protection, refraction, and filtration of some ultraviolet light. It has no blood vessels and receives nutrients through tears as well as from the aqueous humor. It is innervated primarily by the ophthalmic division of the trigeminal nerve as well as the oculomotor nerve.

Cont… The cornea is composed of the

following 5 layers (anterior to posterior):

Corneal epithelium Bowman layer Corneal stroma Descemet membrane Corneal endothelium

Corneal injuryCorneal injury describes an injury to the cornea. The cornea is the crystal clear (transparent) tissue covering the front of the eye. It works with the lens of the eye to focus images on the retina.

Causes Injuries to the outer surface of the cornea, called

corneal abrasions, may be caused by: Chemical irritation from almost any fluid that gets into

the eye Overuse of contact lenses or lenses that don't fit

correctly Reaction or sensitivity to contact lens solutions and

cosmetics Scratches or scrapes on the surface of the cornea

(called an abrasion) Something getting into the eye (such as sand or dust) Sunlight, sun lamps, snow or water reflections, or arc-

welding

Cont.. Infections may also damage the cornea. You are more likely to develop a corneal injury if

you: Are exposed to sunlight or artificial ultraviolet

light for long periods of time Have ill-fitting contact lenses or overuse your

contact lenses Have very dry eyes Work in a dusty environment High-speed particles, such as chips from

hammering metal on metal, may become embedded in the surface of the cornea. Rarely, they may pass through the cornea and go deeper into the eye.

Corneal abrasion

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

Cont… Corneal abrasions usually heal rapidly, without

serious sequelae. But deep corneal involvement may result in facet formation in the epithelium or scar formation in the stroma.

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).

Pathophysiology

Potential causes of corneal abrasion include the following:

Injury (eg, fingers, fingernails, paper, mascara brushes, tree branches, self-inflicted rubbing, pepper-spray exposure, automotive frontal air bags)

Blowing dust, sand, or debris Extended contact lens wear Ocular foreign bodies embedded under an eyelid Iatrogenic - Unconscious patients, 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

Cont… 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)

In persons with trachoma, the constant corneal abrasion by lashes and inadequate tears can produce corneal erosions, ulceration, and scarring. These constitute the major pathway to blindness in trachoma.

Contact lens trauma Contact lens–induced epithelial defects or direct trauma

during lens insertion or removal can cause corneal abrasions.

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 insufficient 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.

Cont…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.

overnight wearing of soft lenses, which do not provide sufficient 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 increases 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.

Sports-related injury Corneal abrasions can occur in almost all

sports. They most frequently occur in young people.

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

Cont…

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 finger or elbow striking the player's eye.

The incidence of severe eye injuries in wrestling is low.

Eyelid surgery In patients undergoing eyelid 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 nonoperative 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.

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 Schiøtz 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.

Physical Examination Visual acuity should be assessed. If the abrasion affects

the visual axis, there may be a deficit in acuity that should be apparent when compared to the uninjured eye.

If the examination is limited by pain, a topical anesthetic such as tetracaine or proparacaine may be used. The amount of anesthetic used should be minimal, as these agents have been shown to slow wound healing.

Visual inspection for foreign objects should be performed. Both upper and lower eyelids should be flipped in order to look for foreign bodies that may be lodged in the upper eyelid, causing injury with eye blinking.

The cornea can become hazy if there is edema due to the abrasion. Conjunctival injection, usually located near the limbus

Slit Lamp Examination

A topical anesthetic (ie, proparacaine, tetracaine) may facilitate the slit-lamp examination. Severe photophobia that causes blepharospasm may require instillation of a cycloplegic agent (ie, cyclopentolate [Cyclogyl], homatropine) 20-30 minutes prior to examination.

 fluorescein instillation 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.

Fluorescein is applied using a paper strip applicator that is gently placed over the inferior cul-de-sac of the eye and allowing saline or anesthetic solution to drop into the eye. Once the patient blinks, the dye is spread over the cornea.

TreatmentCorneal abrasions heal with time.

Prophylactic topical antibiotics are given in patients with abrasions from contact lenses. Traditionally, topical antibiotics were used for prophylaxis even in non-infected corneal abrasions not related to contact lenses, but this practice has been called into question.

Cont…Patching the eye has been used to help

relieve the pain associated with corneal abrasion, but research has not shown benefit from patching. 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, because of potential incubation of infecting organisms and promoting subsequent infectious keratitis.

Cont.. Some ophthalmologists advocate 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 initially. In addition, topical cycloplegics may be required to relieve pain and photophobia in patients with large abrasions until their healing is nearly complete.

Cont.

Emergent ophthalmologic consultation is warranted for suspected retained intraocular foreign bodies. Urgent consultation is needed for suspected corneal ulcerations (microbial keratitis).

Cont.Fluoroquinolones (eg, ofloxacin) 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. In addition, fluoroquinolones have proven efficacy in the treatment of bacterial corneal ulcers. Prolonged and low-frequency dosing should be avoided to discourage the emergence of resistant organisms due to subinhibitory antibiotic concentrations on the ocular surface.

Cont.. 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.

Cont..Antibiotic drops are more comfortable

than ointments but must be administered every 2-3 hours. Antibiotic ointments (eg, bacitracin, polymyxin/bacitracin, erythromycin, ciprofloxacin) retain their antibacterial effect longer than drops and thus can be used less often (every 4-6 h), but they are more uncomfortable because they can cause visual blurring. Ointments are frequently used in children whose crying washes out the drops.

Cont..

Avoid antibiotics containing neomycin (eg, Neosporin) because of the high incidence of allergy to neomycin in the general population. The use of prophylactic periocular injections or systemic administration of antibiotics after corneal abrasions is controversial.

Pain Management

The pain of corneal abrasions 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. These are continued until the pain decreases to the point that it can be managed with over-the-counter analgesics.

Cont..

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 glaucoma, ensure that the patient does not have narrow-angle glaucoma.

Management of Small Corneal Abrasions Small abrasions can be managed on an

outpatient basis. Ice compresses should be used for 24-48 hours to reduce 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 of complications, such as foreign body sensation, conjunctival injection, and decreased vision, so that treatment can be initiated promptly.

Patching

"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."

Follow-Up Care Close follow-up care of corneal abrasions is

necessary because of the 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 forPseudomonas infection and amebic keratitis.

Cont..Patients with abrasions should receive

follow-up care until healing is complete and the fluorescein stain is negative, to confirm that a corneal ulcer has not developed. However, 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.

Cont.. Advise eye rest (i.e., no reading or work that

requires substantial eye movement that might interfere with re epithelialization). Advise patients to avoid bright light or to wear sunglasses for comfort if they have notable photophobia.

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.

Nursing Diagnosis for Corneal Injury

 1. Acute Pain related to trauma, increased IOP, surgical intervention or administration of inflammatory eye drops dilatorNursing interventions:- Give the medication to control pain - Give cold compress on demand for blunt trauma- Reduce lighting levels- Encourage use of sunglasses in strong light

Cont..Risk for self-care deficit related to damage

visionNursing interventions:- Give instructions to the patient or the people closest to the signs and symptoms, complications should be immediately reported to the doctor- Provide verbal and written instructions to patients and the right means of technique in delivering drugs- Evaluate the need for assistance after discharge- Teach patients and families of sight guidance techniques

Cont.. Risk for Injury related to damage vision

Nursing interventions:- Help the patient when able to do until a stable postoperative ambulation- Orient the patient in the room- Discuss the need for the use of metal shields or goggles when necessary- Do not put pressure on the affected eye trauma- Use proper procedures when providing eye drugs

Cont..Anxiety related to damage to sensory and

lack of understanding of post-operative care, drug deliveryNursing interventions:- Assess the degree and duration of visual impairment- Orient the patient to the new environment- Describe the routine perioperative- Encourage to perform daily living habits when able- Encourage the participation of the family or the people who matter in patient care.

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Joyce m black. Medical surgical nursing. New York: web Saunders company; 2003:1245 - 1249

Gerard j tortora. Principal of anatomy and physiology. USA. JOHN wiley publisher; 2006: 686- 688

lippincott. Manual of nursing practice. Newyork: a wulter kluwers company; 2006: 962-972