Pfeffersprayverletzungen des vorderen Augensegmentes

Noxious effects of riot control agents on the ocular surface: Pathogenic mechanisms and management

Riot Control Agents (RCAs) are chemical compounds used by law enforcement agencies to quell violent demonstrations as an alternative to lethal force and as part of police/military training. They are also known as tear gases because of the hallmark ocular irritation and lacrimation they cause. The most common RCAs include oleoresin capsicum (contained in Mace and pepper spray), chlorobenzylidene malononitrile, dibenzoxazepine, and chloroacetophenone (previously the main content of Mace); some of which have been in use for decades. Their immediate incapacitating effects are mediated through polymodal afferent fibers innervating the corneal surface, inducing the release of peptides that cause neurogenic inflammation. Although previously thought to have only transient effects on exposed patients more severe complications such as corneal stromal opacities, corneal neovascularization, neurotrophic keratopathy, conjunctival necrosis, and pseudopterygium can occur. Concerningly, the lack of research and specific therapies restrict the current management to decontamination and symptom-tailored support. This manuscript will provide an overview of the toxic mechanisms of RCAs, their clinical manifestations, and current therapy after exposure to tear gases.

Skin laceration caused by a short distance shot from a pepper spray launcher: a case report

Pepper spray launchers are more precise and wind stable compared to conventional pepper sprays and are commonly used as a self-defensive tool. With the advanced potential, they may also harbour a greater risk for injuries, especially if they are not used within the suggested safety distance. If the shooting distance is below 1.5 m, energy densities may exceed the threshold energy density for the penetration of skin leading to skin laceration. We present a case where a man is hit by the liquid jet of a JPX Jet Protector® with an estimated shooting distance of 0.3 m. The man suffered from a bleeding skin laceration, which had to be sewed in the hospital. This case report furthermore outlines the potentially dangerous effect of pepper spray launchers and thereby their role in forensic investigations.

Incidence and causative agents of chemical eye injuries in Switzerland

CONTEXT

Chemical eye injuries are ophthalmological emergencies with a high risk of secondary complications and severe visual loss. Only limited epidemiological data for such injuries are available for many countries.

PATIENTS AND METHODS

We performed two independent studies. The cause of chemical eye injuries was assessed with a prospective questionnaire study. Questionnaires were sent to all ophthalmologists in Switzerland. A total of 163 patients (205 eyes) were included, between December 2012 and October 2014. Independent of the questionnaire study, the incidence of chemical eye injuries was assessed with a retrospective cohort study design using the database of the mandatory accident insurance.

RESULTS

Ophthalmological questionnaires revealed that plaster/cement (20.5%), alkaline (12.2%) and acid (10.2%) solutions caused the highest number of chemical injuries. Only 2% of all injuries were classified as grade III and none as grade IV (Roper-Hall classification). The official toxicological information phone-hotline was contacted in 4.3% of cases. Using data from the accident insurance, an incidence of chemical eye injuries of about 50/100 000/year was found in the working population.

CONCLUSION

Here, we present data on the involved agents of chemical eye injuries in Switzerland, and also the incidence of such injuries in the working population. This may also help to assess the need for further education programs and to improve and direct preventive measures.

The decrease in aqueous tear production associated with pepper spray

PURPOSE

Pepper spray is used both by civilians and by law enforcement. Burning sensation occurs when exposed to skin, pain and temporary blindness occurs when exposed to the eyes. This study focused on the effect of pepper spray on lacrimal tear production and subsequently on corneal sensitivity in a large group after an intense exposure.

METHODS

Ninety-six people who were exposed to pepper spray during the Gezi park protests volunteered. Subjects were asked if they wore any protective goggles and if they irrigated their eyes after exposure. They were asked to record their symptoms regarding dry eye in a standardized questionnaire. Schirmer I and II tests were performed.

RESULTS

Eighty-two people wore protective goggles during exposure, whereas 14 people did not have any protection. Both Schirmer results in unprotected subjects were significantly lower than that in protected subjects. Schirmer I and II results of unprotected subjects were not statistically different, whereas they were statistically different in protected subjects. Thirty-five percent of unprotected subjects and 24% of protected subjects expressed symptoms of dry eye.

DISCUSSION

The active ingredient of pepper spray is oleoresin capsicum. It is randomly diffused to polymodal nerve terminals, leading to opening of non-selective cationic channels and block neuronal transmission. The lower results of both Schirmer in unprotected group emphasize the importance of a protective Google glass around the eyes during exposal, serving as a barrier minimalizing the contact of the spray with the eyes. The combination of the low results and lack of symptoms could suggest that corneal reflex lacrimation in our subjects was not abundant enough. The findings of this study could not fully represent long term findings but it could be assumed that our findings could be indicative of the sensory denervation and alterations demonstrated in studies investigating the long term effects of oleoresin capsicum.