Clinical effects of oleoresin capsicum (pepper spray) on the human cornea and conjunctiva.
OBJECTIVE
To evaluate the effects of oleoresin capsicum (OC) on the human cornea and conjunctiva and to test the effectiveness of topical anesthetics for relief of pain.


METHODS
Prospective, randomized clinical trial.


METHODS
Forty-seven subjects were examined before and at 10 minutes and 1 hour after exposure to pepper spray during a training exercise. Eleven subjects were reexamined at 1 week after exposure. A short, subjective questionnaire was given asking subjects to rate their pain, blurring of vision, and tearing. After exposure, subjects were randomly given a placebo, a topical nonsteroidal antiinflammatory agent, or a topical anesthetic.


METHODS
Visual acuity and corneal sensitivity with a Cochet-Bonnet aesthesiometer (scale of 1-6 cm) was measured and the eyes were examined with a portable slit lamp using fluorescein. Symptoms of pain, blurring of vision, and tearing were recorded in a ranking of 0 to 10.


RESULTS
Visual acuity was unaffected by exposure to pepper spray. Corneal sensitivity was reduced from a pretest mean of 5.7 cm to a posttest mean of 0.6 cm 10 minutes after exposure. At 1 hour, the mean corneal sensitivity had recovered to 2.9 cm. Twenty-one percent of eyes had evidence of punctate epithelial erosions, but no corneal abrasions were found. All subjects reported significant pain, blurring of vision, and tearing at 10 minutes that was much improved by 1 hour. Topical flurbiprofen 0.03% improved symptoms in two of 11 subjects, whereas topical proparacaine hydrochloride 0.5% improved symptoms in 16 of 29 eyes. At 1 week after exposure, corneal sensation returned to baseline, and no corneal abnormalities were noted.


CONCLUSIONS
The predominant symptom after exposure to OC was pain. Topical flurbiprofen was not helpful in reducing symptoms of exposure, whereas topical proparacaine was effective in relieving pain in most subjects. Corneal sensitivity was dramatically reduced at 10 minutes after exposure and was improved after 1 hour. At 1 week, corneal sensation had returned to normal, as had slit-lamp appearance on all subjects examined.
Zollman
T M
TM
Department of Ophthalmology, University of Washington, Seattle, Washington, USA.
Bragg
R M
RM
Harrison
D A
DA
D000328:Adult; D000700:Analgesics / Q000627:therapeutic use; D000779:Anesthetics, Local / Q000627:therapeutic use; D003228:Conjunctiva / Q000187:drug effects*; D003315:Cornea / Q000187:drug effects*; D005260:Female; D005480:Flurbiprofen / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D010146:Pain / Q000139:chemically induced* / Q000188:drug therapy; D010936:Plant Extracts / Q000009:adverse effects*; D016495:Police; D011430:Propoxycaine / Q000627:therapeutic use; D012678:Sensation Disorders / Q000139:chemically induced* / Q000188:drug therapy; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000139:chemically induced* / Q000188:drug therapy
D000700:Analgesics; D000779:Anesthetics, Local; D010936:Plant Extracts; C018620:oleoresins; D005480:Flurbiprofen; C005717:proxymetacaine; D011430:Propoxycaine