History
Patients with a corneal abrasion typically complain of eye pain and an inability to open the eye because of foreign body sensation. The severity ranges from a mild foreign body sensation in cases of small abrasions to excruciating pain in large abrasions. 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.
Other symptoms include photophobia, especially if secondary traumatic iritis is present, pain with extraocular movement, or blurred vision. Excessive tearing may occur. Conjunctival injection and eyelid swelling may be present. Most patients with concomitant atraumatic iritis can clearly distinguish between the aching discomfort from ciliary spasm and the foreign body sensation or scratchy discomfort from superficial corneal injury.
The patient's history typically includes trauma to the eye due to either a foreign object or a contact lens. Toxic chemicals (eg, ear drops) accidentally instilled into the eye can cause corneal abrasions. Symptoms typically begin instantly after trauma occurs and can last minutes to days, depending on the size of the abrasion. In cases of ultraviolet-related or welding-arc–related actinic keratitis, the symptoms usually begin 6 hours after exposure to the ultraviolet light.
If the source of injury is uncertain, the clinician should take a detailed history, with questions regarding any recent sports activities, ultraviolet light exposure, makeup application, excessive rubbing of the eyes, use of contact lenses (including poorly fitting lenses and duration of use), and motor vehicle accidents. The occupation of the patient should be noted because people using power tools or striking metal with metal may have penetrating globe injuries.
Some patients have recurrent corneal epithelial breakdown days to years after the original abrasion heals. This is called recurrent corneal erosion syndrome. [19] Symptoms include foreign body sensation, pain, and photophobia. Sharp, severe pain; photophobia; and lacrimation most commonly occur when these patients open their eyes in the morning upon 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.
Unconscious patients (eg, patients in intensive care who are sedated and have lost their corneal reflexes) are prone to iatrogenic corneal abrasions, as their eyes remain open for some time and become dry. The nursing staff may inadvertently rub an eye while giving a face bath and abrading the cornea with a napkin or towel.
Physical Examination
In some cases, a corneal abrasion is overlooked because of the insignificant nature of the causative agent or because of insignificant discomfort; however, the majority of patients with corneal abrasions have a definite and consistent clinical presentation. The corneal epithelium is richly innervated with sensory pain fibers from the trigeminal nerve, so most patients with a corneal abrasion are in obvious pain.
The clinical presentation usually is unilateral when the corneal abrasion is associated with trauma. It may be bilateral when it is associated with heritable or dystrophic disease, ultraviolet burns, chemical exposure, or contact lens use.
The eyes should be opened with the lids retracted in order to get a full look at the cornea as well as conjunctiva. Extraocular movements should be assessed, and the pupillary reflex should be elicited. Occasionally, the patient may have a reactive miosis.
If there is any history or signs of globe injury with violation of ocular contents, a plastic or metal shield should be placed and an ophthalmologist should be called urgently.
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. [20] If the patient’s symptoms are relieved by the topical anesthetic and no abrasion or other cause of pain is found, it is the physician’s responsibility to not discharge the patient until the anesthetic has worn off. If the pain recurs, a cause of the pain must be found.
Visual inspection for foreign objects should be performed. The lower lid margin should be drawn downward while the patient looks up to examine the inferior fornix. Drawn downward 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. Also see Intraocular Foreign Body.
The cornea can become hazy if there is edema due to the abrasion. Conjunctival injection, usually located near the limbus, also may be present.
In advanced cases, findings can be more drastic, as follows:
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Bacterial corneal ulcers
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Fungal, amebic, or viral corneal ulcers
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Uveitis
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Recurrent corneal erosions
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Filamentary keratitis
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Corneal abscess
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Corneal perforation
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This corneal abrasion appears as a yellow-green area when stained with fluorescein and viewed with a blue light.
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Corneal abrasion.
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Large corneal abrasion.
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Corneal keratitis and staining.
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Corneal foreign body.
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Corneal foreign body after removal.
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Corneal foreign body with cobalt blue lighting showing abrasion.
