The Southern Walkingstick (Anisomorpha buprestoides) is an inconspicuous insect known for slow movement and camouflage. They are found in the southern United States, Florida and Texas for example, and feed on Oak leaves, Rhododendron leaves, and brambles. While otherwise harmless, this insect has a defense mechanism of spraying a toxic substance at potential predators, such as flying birds. It is known to have excellent marksmanship, often hitting the eyes of the predator. This report is of a significant ocular injury sustained by a child sprayed in the eye by a Southern Walkingstick.

An 8 year old boy was playing in his backyard when he discovered a Southern Walkingstick approximately one foot from his face in a bush. The insect sprayed a red fluid into his face that caused immediate pain and blurred vision in the right eye. The eye was flushed with water at home and in the emergency room.
The following day, he was examined by an ophthalmologist for continued blurred vision and foreign body sensation. A corneal abrasion involving about 30% of the cornea, and a large adjacent conjunctival abrasion were seen. The abrasion slowly healed over a 6 day period with no permanent effects or loss of vision.

The venom of the Southern Walkingstick is known to be locally toxic to mucous membranes, and is painfully irritating if inhaled. Fortunately, the toxin seems to cause only superficial damage, and no reports of permanent scarring has been observed in humans. There is one case involving a dog who subsequently developed a corneal ulcer after injury. Thus, exposure to the toxin should be followed by copious irrigation at the site of injury, with follow-up in the emergency room for further treatment.

INTERVENTION: The patient was treated with cyclopentolate 1% and underwent daily examinations until the corneal and conjunctival epithelial defects resolved.

MAIN OUTCOME MEASURE: Resolution of corneal and conjunctival epithelial defects.

RESULTS: The corneal and conjunctival epithelial defects slowly resolved over 6 days. Visual acuity improved to 20/20 in the affected eye. No residual corneal scarring was evident.

CONCLUSIONS: Slowly resolving corneal and conjunctival epithelial defects can occur from direct contact with the venom from the Southern walkingstick, A. buprestoides; therefore, this insect should be approached with caution.