Abrasion

BASICS


DESCRIPTION


• A corneal epithelial defect from several possible causes:


– Traumatic (most common)


– Nontraumatic


RISK FACTORS


• Related to trauma:


– Athletes without suitable eye protection


– Contact lens wearers


– Industrial workers without suitable eye protection:


Machine operators


Construction trades


Welders


• Poor adhesion of epithelium to basement membrane/Bowman’s layer:


– Previous injury to Bowman’s layer:


– Trauma involving the subepithelium


– Previous ocular surgery, especially refractive surgery


– Recurrent corneal erosion from organic matter:


– Fingernail


– Tree branch


– Corneal dystrophy, especially epithelial and anterior membrane:


Map-dot-fingerprint dystrophy (Cogan’s microcystic) (most common)


Reis–Bucklers, Meesmann’s dystrophy (much less common)


Stromal and endothelial dystrophies have also been described (rare)


Genetics


• Dominant inheritance in many of the corneal dystrophies:


– Cogan’s: Dominant with variable penetrance


– Reis–Bucklers’ autosomal dominant


GENERAL PREVENTION


• Industrial or agricultural workers should wear safety glasses or goggles as appropriate.


• Athletes should consider wearing eye protectors.


• Eyelids should be taped closed in patients undergoing general anesthesia.


PATHOPHYSIOLOGY


Previous injury to Bowman’s layer or certain corneal dystrophies can cause recurrent corneal abrasion months after the initial trauma due to poor adhesion between the epithelium and basement membrane (1)[B].


ETIOLOGY


• Blunt or penetrating trauma:


– Retained conjunctival foreign body


– Paper cut


– Defective contact lens


– Vigorous eye rubbing from unrelated ocular irritation, such as allergic conjunctivitis


COMMONLY ASSOCIATED CONDITIONS


• Eyelid, ocular, orbital trauma:


– Eyelid laceration


– Hyphema/microhyphema


– Orbital fracture


DIAGNOSIS


HISTORY


• Patients almost always can describe the exact time and circumstances of the event that caused the abrasion. If they cannot and the time of onset is vague and the pain seemed to occur spontaneously, you should question a traumatic Dx and be more suspicious of an infectious etiology, e.g., herpes simplex (H. simplex).


– Severe pain


– Redness


– Foreign body sensation


– Photophobia


– Pain on blinking


– Tearing


– Pain worsens with blinking and improves with lids closed


– Visual acuity may be decreased


• Recurrent corneal abrasion patients frequently have a history of prior corneal abrasion(s) in that same eye:


– May have had multiple previous episodes of corneal abrasion in the same eye


– Symptoms frequently occur upon awakening as the eyelids are opened.


– Abrasion may be caused by minimal trauma such as eye rubbing.


PHYSICAL EXAM


• Fluorescein, viewed under cobalt blue light, stains basement membrane revealing the area of absent epithelium:


– Abrasions usually irregular in shape; should measure and diagram to chart progress


– Should not flood the eye with fluorescein. This can cause “pooling” and give the impression of staining where none exists


• A drop of topical anesthetic greatly aids patient comfort and cooperation during the exam. However, do not send the patient home with a prescription for topical anesthetic. This impedes healing.


• Vertical staining lines on the cornea are highly suggestive of a foreign body on the tarsal conjunctiva of the upper lid. Be sure to evert the lid with a cotton stick or with a lid everter.


• Examine both eyes for dystrophic changes, such as map-like lines, microcysts or fingerprint lines. The fellow eye may provide a valuable clue of anterior membrane dystrophy.


• The underlying stroma should be clear. A whitish infiltrate is a sign of infection.


• Examine the eye carefully for other evidence of ocular trauma.


• If the eye was examined over 24 h after the trauma, the abrasion may have healed and the diagnosis of corneal abrasion may only be presumed.


DIFFERENTIAL DIAGNOSIS


• Conjunctival laceration


• Corneal or conjunctival foreign body


• Traumatic iritis


• Infectious keratitis or conjunctivitis:


– H. simplex


– Epidemic keratoconjunctivitis (pink eye)


TREATMENT


MEDICATION


First Line


• Topical antibiotic drops [e.g., polymyxin B/trimethoprim (polytrim), aminoglycoside, or fluoroquinolone] q.i.d.


– Drops have the advantage of allowing better vision during healing.


• Topical antibiotic ointment (e.g., erythromycin, bacitracin, aminoglycoside, or fluoroquinolone) q.i.d.


– Ointments have the advantage of better lubrication so as to decrease the pain that occurs during blinking.


• The dose of either of the above may be increased to per 2 h if infection is a concern.


• Short-acting cycloplegics (e.g., tropicamide or cyclopentolate) may be used if there is photophobia or if traumatic iritis is a concern.


• Topical NSAID drops (e.g., diclofenac or ketorolac) will help decrease pain. Steroids and slow healing should be avoided.


• When treating recurrent abrasions/erosions hypertonic 5% NaCl drops and/or ointment (e.g., Muro 128) q.i.d. increases the adhesion of the epithelium to the basement membrane. Should be continued for 6 months and, on occasion, indefinitely.


• Recurrent erosions are also helped by artificial tears (e.g., systane) and/or artificial tear ointment (e.g., systane PM) after the epithelium has healed. These lubricate the ocular surface to help prevent recurrence.


Second Line


• Sulfonamides have the disadvantage of serious ocular adverse reactions (e.g., Stevens–Johnson syndrome) (rare).


• Chloramphenicol is widely used in Europe but there have been a few reported cases, which some consider questionable, of blood dyscrasias. The eyedrop form has the disadvantage of requiring refrigeration.


• Fusidic acid viscous solution (fucithalmic) is widely used in Canada and Europe. Advantages are the high efficacy with gram positives, especially staph, and the b.i.d. dosage. A disadvantage is the weak efficacy with gram negatives.


ADDITIONAL TREATMENT


General Measures


Pressure patching is not necessary for small abrasions but can help healing and comfort if the abrasion is large. If the patient is more comfortable with the eye closed, then patch. If you do not know how to apply a proper pressure patch, it is better not to patch at all. A loose gauze pad over an open eye may abrade the cornea further and prevent healing or may even make the abrasion larger. If there is a suspicion of infection, i.e., if a whitish corneal infiltrate is seen or if plant matter or a fingernail was the cause of injury, then patching may worsen the infection and should not be used. If the patient is a contact lens wearer, the abrasion should be assumed to be infected and patching should not be done. The contact lens should not be worn until the cornea is healed (2)[A], (3)[A].


Issues for Referral


• Cases with noninfected abrasions and no other ocular trauma usually heal quickly and need not be referred.


• Cases with infection or which show poor or no response to the above treatment should be referred.


Additional Therapies


• Bandage contact lens


• Epithelial debridement and diamond burr polishing of Bowman’s layer (4)[B]


• Anterior stromal puncture


• Alcohol delamination/debridement


SURGERY/OTHER PROCEDURES


• Anterior stromal puncture by the Nd:YAG laser


• Excimer laser phototherapeutic keratectomy


ONGOING CARE


FOLLOW-UP RECOMMENDATIONS


• Patients should be seen daily for signs that the epithelial defect is improving. Document size of defect at every visit.


• When healing progress is certain, you may extend exam interval to 2–3 days.


• When epithelial defect is completely closed, you may extend exam interval to 3–5 days. Discontinue antibiotic. Continue NSAID and/or cycloplegic as necessary. Instruct all patients about the possibility of recurrent abrasions.


• Discharge when the epithelial surface is restored to normal. If this is a recurrent erosion, continue artificial tears and/or ointment and hypertonic saline drops and/or ointment as above. Follow-up for recurrent erosions may be extended and patients may become familiar with the symptoms of a recurrence. They should be instructed to return immediately if a recurrence is suspected.


COMPLICATIONS


Untreated corneal abrasions can progress to bacterial keratitis and corneal ulceration. All patients should be informed of this possibility and the need for immediate management if this occurs.



REFERENCES


1. Ramamurthi S, Rahman MQ, Dutton GN, et al. Pathogenesis, clinical features and management of recurrent corneal erosions. Eye (Lond) 2006;20(6):635–644.


2. Turner A, Rabiu M. Patching for corneal abrasion. Cochrane Database Syst Rev 2006;(2):CD004764.


3. Watson SL, Barker NH. Interventions for recurrent corneal erosions. Cochrane Database Syst Rev 2007;(4):CD001861.


4. Aldave AJ, Kamal KM, Vo RC, et al. Epithelial debridement and Bowman’s layer polishing for visually significant epithelial irregularity and recurrent corneal erosions. Cornea 2009;28(10):1085–1090.

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Nov 9, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on Abrasion

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