Howard Palte, MBChB
University of Miami System of Health 

Ocular trauma is common arising secondary to sports injury, road accidents, assault and leisure. The quoted incidence is imprecise because estimates are retrospective and drawn from hospital records and population surveys. However, the World Health Organization (WHO) estimates there are 55 million injuries globally with more than 2.5 million occurring in the United States, alone. The majority (90%) occur in males, particularly those in the 15-24-year age group.

The Ocular Trauma Study Group divides eye trauma into open and closed globe injury with further classification according to type, grade, pupil response and zone of injury (Table 1). Moreover, the area affected is divided into three zones, viz. zone I (limited to the cornea and limbus), zone II (< 5mm posterior to limbus) and zone III ( > 5mm posterior to limbus).

The primary considerations in the management of eye trauma are control of intraocular pressure (IOP) and preservation of ocular integrity by preventing extrusion of ocular contents. In brief, the primary factors affecting IOP are changes in intraocular volume (blood and aqueous humor), orbit compliance and external compressive forces. Intraoperative coughing, straining and retching result in massive increases in IOP and pose significant threat to visual outcome.

Anesthesia management of ocular trauma extends beyond the eye., The preoperative evaluation is important because there may be additional factors that modify the anesthesia plan. The provider should determine the mechanism of injury and examine for associated injuries, especially head trauma. In certain instances, additional investigations  such as, CT scan orbit and head and metabolic panel may be warranted.

For decades, general anesthesia (GA) has been preferred for repair of open globe injuries (OGI) because it provides ocular akinesia, lowered IOP, airway control and eliminates the peril of unexpected patient movement. Anecdotal reports, dating back to the 1950s, stressed avoidance of succinylcholine because of elevations in IOP and extrusion of ocular contents. However, succinylcholine  may be considered in select OGI when airway control or aspiration is of concern because it produces moderate and transient increases in IOP (9mmHg), and not an implicated precursor of vitreous expulsion. The drawbacks of GA  include risk of regurgitation, increased nausea and vomiting and significant increases in IOP with coughing and bucking.

Regional anesthesia (RA) with monitored anesthesia care (MAC) is an alternative option in select open globe injuries. A retrospective review at a leading eye institute examined outcomes of eye injuries managed under RA + MAC in terms of  long-term visual acuity. It found that anterior (Zone I & II) injuries and intraocular foreign bodies (IOFB) managed under RA & MAC resulted in reduced operative times, and no statistical difference in visual acuity at 2-month follow-up.

The regional anesthesia technique used in open globe injuries requires modification in order to prevent fluctuations in IOP. Eyelid squeezing causes massive increases in IOP and is attenuated by performance of a facial nerve (VII) block, commonly adopting a modified van Lint approach. The subsequent extraconal (peribulbar) block is performed using a restricted volume (5-6 ml) of LA injected in small aliquots over 2-3 minutes (limiting external compressive forces on the globe).

Eye injuries in children require operative repair under GA. It is estimated that 90% of these injuries are preventable because the majority occur at home when there is no parental supervision.  The mechanism varies with age with cleaning products injuring toddlers and older children more likely to sustain sports and projectile insults.

Primary closure of open globe injuries is optimally achieved within 24 hours. Long-term visual outcomes are determined by initial visual acuity . The US Eye Injury Register indicates that long-term visual acuity is determined by presenting light perception. Ultimately, 3 /4 patients retain a degree of vision and 20% regain normal light perception.