General Medical Information

Superficial Injuries of the Cornea and Conjunctiva

Jean Edwards Holt

The cornea and conjunctiva, although important, are considered superficial eye structures, and injuries to them often can be managed by a primary care physician. Subconjunctival hemorrhage usually is without sequelae, behaving as a bruise elsewhere on the body. The patient should be reassured that the blood clears over a 10- to 20-day period. The hemorrhages can be caused by minor trauma or by coughing or sneezing. They also can occur spontaneously. There is little or no value in performing hematologic or blood coagulation studies for patients with spontaneous subconjunctival hemorrhages unless a history of frequent recurrence is given. In those cases, the possibility of blood dyscrasia should be considered. These patients have a bright red eye, normal vision, and no pain. If subconjunctival hemorrhage is a manifestation of severe trauma, however, the physician always must rule out more serious injuries to the deeper ocular structures.

Corneal or conjunctival foreign bodies first should be approached with irrigation. If this is not successful, they can be brushed with a cotton-tipped applicator or nudged out with a small pick or needle. One drop of topical anesthetic solution usually is all that is necessary to manipulate the object. If a foreign body is not seen, but the symptoms or history indicate the presence of one, fluorescein stain can be used to outline a corneal abrasion. A small strip of fluorescein paper is moistened with sterile water, and this strip is applied to the inferior cul-de-sac while the patient looks up or the superior cul-de-sac while the patient looks down. When a cobalt blue penlight or Wood lamp is used, fluorescence may outline the abrasion. If the patient wears soft contact lenses, use of fluorescein should be avoided, because the dye can permanently stain the lenses. The pain of corneal abrasion is sharp and stabbing. It is aggravated when the patient opens and closes his or her eyes and is associated with marked photophobia, unlike the deep ache of iritis and the superficial mild and intermittent discomfort of conjunctivitis.
If the abrasion is vertical over the cornea, the lid should be everted, and often a foreign body is found under the upper lid. For lid eversion, the patient looks down while a cotton-tipped applicator handle, pencil eraser, or finger is placed just beneath the orbital rim. The eyelashes are grasped with the other hand and pulled straight out from the globe, the lashes are pulled up and forward, and the eyelid flipped over with the applicator stick, pencil, or the base of the finger as a fulcrum. The everted lid is held against the orbital margin, and the underlying structures are examined. Approaching the patient with confidence makes this procedure simple.

Overwearing contact lenses or excess exposure to an ultraviolet sunlamp can cause severe punctate corneal damage with eyelid edema. Treatment usually is observation. Symptoms appear 6 to 12 hours after exposure or after the contact lenses are taken out. The patients experience marked light sensitivity and a feeling of sand or grit in the eyes. Superficial pain can be severe. There is marked spasm of the lids and associated tearing. Both eyes usually are involved.

Misplacement of contact lenses is a common emergency. The lens usually can be found with adequate evaluation in the deep folds of the conjunctival fornices. The patient should be reminded that if it is not found, the lens did not migrate posteriorly into the intracranial structures but rather dropped out.
Therapy for corneal abrasions, including treatment after removal of a foreign body, consists of antibiotic eyedrops. This is recommended if the injury was caused by contaminated material, such as a fingernail or branch. If there is a large abrasion and the eye is quite inflamed, a cycloplegic agent can be used to reduce the ciliary spasm and pain. The eye often is patched for comfort and to speed healing. Glucocorticoids or glucocorticoids-antibiotic combinations should not be prescribed, and topical anesthetics should not be given for home use. Most small abrasions heal in 24 hours and larger ones in less than 1 week.