|CORNEAL ABRASION AND RECURRENT CORNEAL EROSION
SIGNS AND SYMPTOMS
Recurrent corneal erosion (RCE) is characterized by repeated, spontaneous disruption of the corneal epithelium. In most cases, the malady is preceded by mechanical trauma, such as a corneal abrasion caused by a fingernail.
Patients with RCE usually present to the office with a history of corneal abrasion in the involved eye, often months or years previously, and a chief complaint of recurrent episodes of ocular pain that may also include foreign body sensation, photophobia, blepharospasm, decreased vision or lacrimation upon awakening or following eye rubbing or eye opening.
Clinical signs include a localized, visible roughening of the corneal epithelium which stains superficially with fluorescein dye. The lesions are typically unilateral and in the vicinity of the original corneal defect. Bilateral or idiopathic lesions suggest a basement membrane dystrophy. The phenomenon may occur as frequently as daily or as sparsely as biweekly or monthly.
Epithelial basement dystrophy is an associated finding in many cases. It is marked by small, intra-epithelial dots and subepithelial ridges and lines (maps, fingerprints), representing poor adhesion of the epithelial basement membrane and Bowmans layer.
The cornea has remarkable healing properties. The epithelium adjacent to any insult expands in size to fill in the defect, usually within 24 to 48 hours. Lesions that are purely epithelial often heal quickly and completely without scarring. Lesions that extend below Bowmans are more likely to leave a permanent scar.
The epithelial healing process begins when basal epithelial cells undergo mitosis, producing new cells that occupy fresh wounds. Basal cells adhere the epithelium to the stroma in two ways: they secrete the basement membrane and they contain hemidesmosomes, which are essentially linchpins that protrude through the posterior surface of basal cells and into the stroma; each is held in place by an anchoring fibril. Any disruption to basal cell production will make the eye more prone to recurrent erosion.
Begin treatment with cycloplegia (atropine 1% for the worst cases, homatropine 5% for moderate cases and cyclopentolate 1% for the mildest) and a topical antibiotic such as Polytrim, gentamicin or tobramycin (Tobrex). Recommend bed-rest, inactivity and OTC analgesics. If pain is severe, prescribe a topical nonsteroidal anti-inflammatory (Voltaren, Acular or Ocufen, b.i.d. to q.i.d.) and/or a thin, low-water content bandage contact lens.
Today, pressure patching is somewhat controversial. When patients are not in a great deal of discomfort, most abrasions do not require patching. Larger abrasions may fare better with patching. The medicinal and homeostatic effects of patching help to keep patients still, quiet and more comfortable. Reevaluate the patient every 24 hours until the abrasion is re-epithelialized. Bandage soft contact lenses have nearly supplanted the traditional pressure patch in the management of corneal abrasions.
Treat recurrent erosions in much the same way. But bear in mind that, in this instance, larger defects may require patching. If pressure patching is unnecessary or contraindicated, prescribe a topical antibiotic drop q.i.d. with an antibiotic ointment at bed-time.
If the corneal epithelium is not healing properly within 24 to 48 hours, debride the area to give the epithelium a clean slate on which to regenerate. Instill a topical anesthetic, then remove the involved epithelium with a cotton-tipped applicator soaked in saline. Any of the above steps can be followed after the procedure.
The most severe, recalcitrant cases may require anterior stromal puncture (purposeful scarring of the involved area using a 23- to 25-gauge bent needle). This is accomplished by anesthetizing the cornea, then using the needle to puncture the epithelium to the levels of Bowmans membrane or anterior stroma in the affected area.
The final step in managing RCE is hypertonic therapy. Sodium chloride drops and ointments (2% and 5%) applied to the eye q.i.d./q3h during the day and at bedtime will help to reduce corneal swelling, lubricate the corneal surface and promote epithelial adherence. Interestingly, they also may help to restore vision.
Other reports in this section
Eyelids & Eyelashes | Conjunctiva & Sclera | Cornea
Uvea | Vitreous & Retina | Optic Nerve & Brain | Oculosystemic Disease
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