Definition

Eye injuries are most commonly caused by a foreign body (35% of cases), open wounds (25% of cases), contusions (25% of cases), and burns (15% of cases). Approximately 35% of eye injuries occur in patients younger than 17 years old. Eye injury is the most common cause of monocular blindness in the United States.

Recognition

Generally, the diagnosis of open globe injury can be surmised from the history and physical examination. Trauma to the head or face, foreign bodies such as metal or wood pieces, and industrial accidents are usually identified during the initial assessment.

In any patient who sustains trauma to the head, the globe and vision must be evaluated.

Risk Assessment

The goals of anesthesia for eye surgery are to provide anesthesia and profound analgesia; avoid coughing, retching, or vomiting; and avoid forceful blinking or crying. Damaging increases in intraocular pressure (IOP) ( Box 67.1 ) can cause extrusion of the ocular contents in patients with an open globe.

The most common risk and concern associated with open globe injury besides extrusion of the eye contents is a full stomach. This risk involves not only the possibility of aspiration of gastric contents but also the fact that drugs or maneuvers used to manage the patient can cause an increase in IOP. Another significant concern is the occurrence of endophthalmitis. Most guidelines recommend that the eye should be repaired within 24 hours of the eye injury. Antibiotics should be started as soon as possible.

Normal blinking increases IOP by approximately 5 to 10 mm Hg from baseline (normal IOP ranges from 10 to 20 mm Hg). Hypoxemia may raise IOP via vasodilation of the choroidal arteries. Sustained hypertension may increase IOP, and induced hypotension may decrease IOP. Vomiting, coughing, or “bucking” causes the most dramatic increase in IOP by causing congestion in the venous system, impeding the outflow of aqueous humor, and increasing the volume of choroidal blood. This increase in pressure may be as high as 30 to 40 mm Hg. In poorly anesthetized patients, laryngoscopy can increase IOP by up to 20 mm Hg.

Implications

Following induction of anesthesia, the administration of succinylcholine increases IOP by approximately 5 to 10 mm Hg for about 5 to 10 minutes. IOP returns to baseline after that period of time. In the open globe, however, the IOP is atmospheric pressure. There are no reports of extrusion of ocular contents in patients who presented with a ruptured globe and received succinylcholine for intubation.