Cornea epithelial abnormalities

Capsaicin causes conjunctivitis, periorbital edema/ erythema, ophthalmodynia, blepharospasm, blepharitis, corneal abrasions, and lacrimation. In a retrospective study of 81 patients who presented to the emergency department following aerosol exposure from law enforcement use of OC, 56% of individuals developed ophthalmodynia, 44% conjunctivitis, 40% conjunctival erythema, 13% lacrimation, and 9% comeal abrasions (Watson et al, 1996). Another study involved exposure of 47 human volunteers to OC for evaluating effects on the cornea and conjunctivae (Zolhnan et al, 2000). All subjects reported significant eye pain, blurred vision, and lacrimation 10 min after exposure to OC pepper spray, but symptoms improved by 1 h later. Comeal abrasions were not apparent, but 21% of subjects showed evidence of punctate epithelial erosions and reduced comeal sensitivity. Comeal abnormalities were absent 1 week after exposure. Another human study identified 23% of subjects (7 of 30) with comeal abrasions following aerosol exposure to OC spray (Watson et al, 1996). In mice, a single subcutaneous injection of 12.5, 25,... 

Noninfectious indolent epithelial ulcers also can occur in HSK.These ulcers, formerly referred to as metaherpetic lesions, tend to be ovoid, 2 to 8 mm in size, with smooth rolled edges. They may be caused by damage to the epithelial basement membrane due to inflammation, tear film abnormalities, neurotropic cornea, or toxicity from antiviral medications. These ulcers may be recalcitrant, resulting in neovascularization and scarring. 

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