CHAPTER 13

Clinical Aspects of Toxic and Traumatic Injuries of the Anterior Segment

Injuries Caused by Temperature and Radiation

Thermal Burns

Heat

Rapid-reflex eyelid closure, Bell phenomenon, and reflex movement away from the source of intense heat usually limit damage to the globe from flames. Burns from molten metal that stays in contact with the eye are more likely to cause corneal injuries that result in permanent scarring. Heat is a major inducer of inflammation and stromal protease expression and can lead to collagen melt if severe. The major objectives of therapy for burns caused by heat are the following:

Relieve discomfort.

Prevent secondary corneal inflammation, ulceration, and perforation from infection or from exposure caused by eyelid damage.

Minimize eyelid scarring and resultant malfunction.

A cycloplegic agent can help relieve discomfort from secondary ciliary spasm or iridocyclitis. Prophylactic antibiotics (topical and/or systemic) can help prevent infection of burned eyelids and/or reduce the chances of infectious corneal ulceration. Limited debridement of devitalized tissues and granulation tissue, used with full-​thickness skin grafts and tarsorrhaphy, helps minimize eyelid scarring and ectropion. Burned ocular tissue can be protected temporarily by covering the eye with a lubricant and a piece of sterile plastic wrap. Topical corticosteroids help suppress any associated iridocyclitis, but they can also inhibit corneal wound healing and must be used with caution and, in general, for short periods.

Hair-curling irons are a common household cause of corneal burns. These burns are usually limited to the epithelium and generally require only a brief period of antibiotic and cycloplegic therapy.

Ocular electrical injury can cause corneal epithelial erosion.

Freezing